ABSTRACT. It is well known that climate change is mainly due to greenhouse gas emissions from human activities. One of the most important consequences is the modification of the hydrologic cycle with significant implications for water resources Extreme precipitation is very erratic and its trends are less spatially coherent than those in average rainfall. On a global scale there are significant unevenness and places where heavy rainfalls are increasing seem to prevail over areas where they are decreasing. The analysis of trends in annual maximum rainfall depths, Hd, for a given duration, d, should be performed only for long-term rainfall data recorded, for example, from the earliest decades of the last century. Furthermore, analyses on the Hd series for d<1 h are rarely available since, in the last century, all rainfall data have been recorded adopting different temporal aggregations (or time resolutions), ta, dependent on changes in the recording systems through time. Currently, rainfall amounts are measured by tipping bucket sensors and recorded in a data-logger for each tip-time associated with a fixed rainfall depth, but until the last decades of the 21st century they were recorded only over paper rolls (pluviograph), generally with hourly ta. In addition, in many years, especially before the Second World War, only daily rainfalls are available, recorded each day at a specific local time and measuring the accumulated depth during the previous 24 h. On this basis it can be deduced that before the advent of data-loggers rainfall data were always characterized by coarse temporal aggregation, with probable effects on analyses based on their use. In fact, in some cases the correct values of Hd can be significantly underestimated up to 50%, especially when d=1 h and 24 h due to the high probability of the presence of values with ta/d=1 (Morbidelli et al., 2018). Moreover, long series of Hd values, together with a percentage of values obtained from continuous data (more recently recorded), always contain a percentage of elements derived from data characterized by coarse temporal aggregation, that are therefore potentially underestimated. This problematic, as well as the replacement of stations, the use of various rain gauge types with time and the change of surrounding near the equipment, could produce important effects on associated analyses, including the determination of rainfall depth-intensity-frequency curves and trend evaluation of intense rainfalls. By using some of the more common climatic trend tests characterized by very different approaches the main objective of this work is to evaluate the effect of time-resolution of rainfall data on trend estimation for annual maximum depths with duration 24 hours. We focus our attention on the Hd series with d=24 hours because they are among the longest and most frequently available series for analyses of climate trends. However, similar analyses could be carried out for different d.

ABSTRACT. In arid regions, such as Israel, surface hydrology is characterized by flash floods which are usually intensive, rapid and responsible for the most fluvio-morphological changes. Water discharge (Q) is one of the key parameters needed for characterized and understanding the dynamics of the stream environment. Q could be calculated by multiplying the wetted cross-sectional area by the mean flow velocity. Using direct and intrusive measuring instruments for determining the flow velocity (e.g., Mechanical Current Meter and ADCP) is very common. However, these instruments required being inside the flow, hence safety and logistic issues limit the applicability of measuring intensive flows. Consequently, discharge estimation is based mainly on hydrological models. These models, such as Manning, have a significant inaccuracy derives primarily from the velocity component and the difficulty in accurately determining the roughness coefficient. Our research objective is to improve both the accuracy of discharge estimation and the ability to monitor flash floods. The stream flow velocity is determined by remote sensing method named LSPIV. This method is based on photograph recording and determination of the displacement of natural objects in the flow. The LSPIV produces a two-dimensional velocity field of the water surface and its significant advantage is the ability to measure automatically, continuously and during all flow conditions. Four LSPIV stations were deployed at streams with wide range of bed roughness. The examined streams from the smoothest to the roughest are Shiqma, Ramon, Zin and Arugot, Israel. During the 2020 2021 winter, four flood events were captured at the LSPIV gauging stations. The documented video frames were analyzed to calculate surface water velocities and in one event were validated with a Surface Velocity Radar measurements. Thereafter, the variation of water discharge and roughness coefficients were determined.

ABSTRACT. Precipitation data is the critical for flood monitoring and prediction applications. Relying on ground measurements from rain gauges is limited by the spatial and temporal coverage. Satellite precipitation products have been known to provide accurate and real-time precipitation data. The accuracy of SPPs for flood monitoring and prediction has been tested across the globe by comparing them to ground observations. This leaves a knowledge gap with regards to evaluating and comparing the performance of different SPPs under diverse settings. In this article, an evaluation of the application of various SPPs for flood monitoring and prediction under diverse settings was conducted. A meta-data analysis extracted data from all previous studies to be able to derive general observations on the performance of SPPs in flood monitoring and prediction. Results showed that SPPs have their uncertainties and discrepancies along with their strengths. However, the performance of SPPs for flood monitoring and prediction is primarily influenced by many factors and needs to be enhanced before their adoption in various applications.

ABSTRACT. Tracer techniques based on the infrared thermography and fluorescent properties of quinine can help on the visualization of shallow flows and allow a quantitative measurement of overland flow velocities. Experiments were conducted to compare the traditional dye tracer, thermal tracer techniques and fluorescent (quinine) tracer by injecting a hot quinine solution into shallow flowing surface water. The leading-edge tracer velocities were estimated from videos of the experiments. The results show that the quinine tracer can be used to estimate both overland and rill flow velocities, since measurements are similar to those resulting from other commonly used tracers. The main advantage of thermal tracers is the visibility of the leading edge in the presence of mulch. The main advantage of using the quinine tracer is the higher visibility of the injected tracer under ultraviolet A (UVA) light, under low luminosity conditions (e.g. night conditions).

ABSTRACT. In most hyperarid regions, surface water is only available in rare, short-lived flood events. To promote agriculture in the Arava Valley in southern Israel and increase water availability, six water reservoirs were established along the Arava with a total potential 10 million m3 capacity. The establishment of these reservoirs was based on the premise that accumulated floodwaters could be used directly for irrigation of agricultural fields and for upper alluvial aquifer replenishment. These goals were not achieved. First, water accumulating in the reservoirs did not meet the agricultural needs due to salinity differences between floodwater and groundwater. More relevantly, the reservoirs were sealed due to the accumulation of silty-clay layers, hence groundwater enrichment could not take place. The accumulated water therefore evaporated instead of being used for agriculture. Moreover, the reservoirs, affected the natural flow pattern of the local Arava River and, thus, indirectly damaged agricultural farms. Long-term sediment accumulation in the reservoirs decreased their capacity – thus their life expectancy, and large, extreme flood events overflowed the reservoirs damaging their structure and agriculture downstream. For reservoir planning and maintenance, there is need to estimate the rate of sediment deposition.

Sediment yield from the Nahal Nehushtan watershed (11.9 km2) located in the Timna Valley in southern Israel, was determined by assessing stratigraphic sections in its 60-year reservoir deposits. Stratigraphic correlation between event couplets allowed quantification of sediment yields representing 13 former flow and flood events. Based on the sediment volume in the reservoir, the 29.8 t km-2 y-1 average sediment yield is one of the lowest among other studied warm deserts. Based on event reservoir sedimentation from watersheds located in several hyper-arid areas in the Middle East and North America, we demonstrate that sediment load increases with drainage area as expected, and that mean annual sediment yield increases with flood frequency in hyper-arid areas. Our quantitative results together with previous studies of hyper-arid areas provide complementary evidence of the drivers influencing fluvial sediment yields, an important key-player in planning the long term efficiency of reservoirs in hyper arid areas.

ABSTRACT. Siltation is currently a concern of water projectors and operators in Tunisia and in the Mediterranean region, as national demand for water is still growing. In this paper we present the results of quantifying and assessing the siltation of Sidi Salem Dam by P.I.S.A model using input data of year 2006. The dam is located in the High Valley of Medjerda which is characterized by a semi-arid climate and steep slopes. It covers an area of 8649 km2, in the Tunisian part. Using Thiessen polygon in ArcGis applied on a series of rain, for 16 rain gauges stations, ranging from 1980/81 to 2014/15, the annual average of rainfall is estimated to 477 mm. The evolution of the silt in Sidi Salem dam is conditioned by climatic, morphological and physical factors of the watershed that are considered by the model. In our case, first application of P.I.S.A. model gave negative value; we explained this result by the important area of the watershed. We proceed, then, to a sensitivity study; the eroded area (which depends on the area of the watershed and land cover) has a significant influence on the rate of sedimentation compared to the other 4 parameters. Based on these two points, we proceed to subdivide the basin into 7 sub-basins. Then, the model was applied on each sub-basin after determining the specifics parameters. By adding up the siltation indices of each sub-basin, we obtain a cumulative sedimentation rate equal to 414.76 Mm3. This result is overestimated by 2.45 times compared to the bathymetric survey (169 Mm3).

ABSTRACT. Hydrological models have been developed for many different reasons and therefore have many different forms. The basic assumption of all hydrological models is that the hydrological processes, as well as the relationship of precipitation and runoff, are stationary over time. Climate change and human activities have altered the process of terrestrial hydrological cycles and rendered the precipitation and runoff relationship nonstationary. Applicability of existing hydrological models in the changing conditions needs to be assessed using more advanced statistical methods that account for this non-stationarity. This presentation reviews the progress towards the development and application of the model evaluation methods and discusses the future perspective of this new emerging area of hydrological modeling under changing environmental conditions.

ABSTRACT. With the growing shift of population centres towards the coast, water abstraction from coastal aquifers is, in many parts of the globe, now an essential part of life. In nearshore areas with higher tidal ranges, lenses of saltwater can form above freshwater, as a result of infiltration during high tides or storm surges to impact groundwater quality. This is in addition to the classical deep, dense saltwater wedge often observed in coastal aquifers. In such areas, particularly those in Southeast Asia, abstraction wells are often open-topped and are therefore particularly susceptible to increases in sea-level and tropical storm surges associated with climate change, and frequently contaminated with salt. The interplay between the saltwater and freshwater dynamics in these regions can present significant economic and feasibility concerns, particularly around the issue of saltwater intrusion due to pumping. Typically, it is understood that deeper wells prove more susceptible to saline intrusion (SI), due to pumping inducing up-coning of the deep saltwater wedge, however with the presence of an upper lens of saltwater, this may not always be the case. Electrical resistivity imaging (ERI) has been proven to be an effective and popular tool to monitor dynamic subsurface water interactions, especially in the field of saltwater intrusion. By measuring changes in electrical resistivity, the contrast in that of salt and freshwater renders it particularly suited to such a task. This study employs temporal three-dimensional ERI and water conductivity sensors within a pumping test in the nearshore part of a homogenous coastal aquifer to establish the feasibility of water extraction in this type of environment. Using this approach, it has been possible not only to characterise the aquifer, but also to establish the parts of the aquifer which are best suited to water abstraction. Findings have enabled identification of an often-overlooked source of groundwater, and the development of appropriate well design to optimise its use. More specifically, ERI enabled the significance of an upper saline cell to be better defined, suggesting that deeper abstraction wells will yield less-saline water if pumped appropriately, within the saltwater limits for drinking water.

ABSTRACT. The moisture content of the soil plays an essential role in terrestrial ecosystems' hydrological cycles and it is a crucial ecological aspect in sandy environments. The spatial variance in soil water content is caused by a variety of factors: dynamic or fast-changing variables and static or slowly changing factors. A detailed analysis of the vadose zone and topsoil in the coastal dunes of arid regions is needed as it determines the ecohydrology of the desert environment. The objective of this study was to investigate soil hydrology if the coastal dunes (Nabkhas), in particular, observe the moisture content redistribution after a 13 mm rainfall event. The field investigation was done in the Al-Hail North area, Oman. The area is a sabkha landform that is affected by a shallow water table (about 1.4 m below the land surface). Coastal dunes (Nabkhas) are abundant there. Three different Nabkhas, N1, N2, and N3, were investigated. The length (L) and height (H) of each Nabkha were measured. The native plants were found in all selected Nabkhas. The native plant in N1 was a live shrub (Haloxylon salicornicum). In N3 the same type of shrub was dead. For N2, the native plant was (Salvadora persica). Profile excavations were made for three Nabkhas, and soil samples were collected from the interdune and from the core of Nabkhas to be analyzed for grain size distribution. Decagon EC-05 sensors were inserted at the depths (0, 20 cm) in the vertical excavations of N1, N2, and N3 to monitor the diurnal variations of ϴv along the Nabkha vertical profile. The variation of ϴv shows a significant increase of ϴv in the top sensor immediately after the rain event. While the bottom sensor has a trivial increase with time. The value of ϴv in the top sensor kept increasing and reached the maximum ϴv= 0.1 m3/m3 on the last day of the rain event. Then, ϴv started to decrease again and reached the minimum value ϴv= 0.054 m3/m3 after 8 days as the evaporation took place during the post-rain time. On the other hand, the bottom sensor approached the maximum ϴv = 0.58 m3/m3 on the last day of recording. This spatial and temporal variation of ϴv in Nabkhas is also strongly affected by the condensation of water from the humid ambient air and around the native shrubs. The high moisture content at the top layers of dunes has a strong impact on the vegetation patterns. This study will aid in the restoration of desert vegetation and in the apprehending of the resilience of soil-water-plant small-scale ecosystems in arid regions. Additional study on soils, water availability, and microclimate in Nabkhas is necessary to better understand the process of plants’ distribution and functioning in these landforms.

ABSTRACT. The objective of this study is to conduct life cycle assessment (LCA) to evaluate the environmental impact and benefits of treating municipal wastewater to tertiary quality compared to conventional water production for agricultural use. The conventional method compared is the dominant seawater desalination using multistage flash distillation (MSF) as its intended to save on its production, but for agricultural use. The study follows the ISO 14040/44 standards and uses a functional unit of 1 Mm^3of tertiary treated effluent (TTE). The modeling concept adopts the cradle-to-gate consequential paradigm. The life cycle inventory include: infrastructure, grid, materials, energy requirements, chemical additives and sludge disposal, for primary, secondary and tertiary treatment. The life cycle impact assessment is applied on both the characterized and normalized level using the ReCiPe method.

ABSTRACT. The objective of this study is to evaluate two local SWRO DPs environmentally using life cycle assessment (LCA). Statistical analysis investigates the correlation between different seawater parameters: salinity and turbidity, and the environmental and economic impacts. The results indicate that the environmental impact for SWRO DPs in Kuwait is at least 40% higher than a typical RO plant with respect to of Fossil Depletion (FD), Climate Change (CC) and Particulate Matter Formation (PMF). The regression analysis indicates the significant contribution of turbidity to the consumption of ferric chloride, sulfuric acid and anti-scant.

ABSTRACT. Typhoon Ulysses (Vamco) brought about more than 300 flooding incidents in November 2020. Region II (Cagayan Valley)had the highest worth of damages to infrastructure and agriculture. This study analyzed the effect of Typhoon Ulysses in Cagayan province using satellite imagery. The VV and VH bands of Sentinel 1 were used to capture the flood inundated areas before (November 1) and after (November 13) the typhoon. Larger flooded areas and agricultural areas were detected by the VH band (72,722.30 and 37,736.70 ha, respectively) than that by the VV band (69,501.12 and 35,606.59 ha, respectively). Studying the backscatter intensity of the two polarizations before and during flooding on representative points showed that VV polarization is more suitable in monitoring vegetation while the VH polarization is more suitable in determining flood extent. The observed flooding in Cagayan could be attributed by the low elevation and slope of the affected areas, high rainfall (200-300 mm) received, and the amount of water released from Magat Dam. A significant part of the 35,000 ha flooded agricultural area was observed to be in Alcala town. Using MODIS, Sentinel 1 and 2 a threshold NDVI of 0.3, results showed that the standing crops in Alcala during the typhoon (660.55 ha) increased after the typhoon (923.16 ha) when the flood subsided. Furthermore, majority of the crops were at the maturity stage before the typhoon, reaching the harvest stage several days after the typhoon.

ABSTRACT. Groundwater monitoring and data acquisition are pre-requisites for the effective management of groundwater resources. Monitoring makes groundwater visible. Typically, quantitative data monitored are groundwater levels and groundwater discharges and recharges (e.g., wells abstraction rates), while qualitative data monitored are those related to groundwater quality, such as salinity and concerned case-specific pollutants. Groundwater levels and groundwater quality provide information on the conditions of groundwater, hence termed groundwater “state variables”, while groundwater recharges and discharges provide information on the groundwater budget and explain the conditions of these two state variables. Continuous information obtained from monitoring networks of a given groundwater resource is used as significant indicators for the status of that resource, and subsequently, management schemes are made in order to develop and utilize this resource on a sustainable basis. In this study, the existing groundwater level and quality monitoring networks in the Kingdom of Bahrain are analyzed for their comprehensiveness and effectiveness in providing adequate information on the groundwater system in the Kingdom, and recommendations for their upgrade are made along with legislation requirements and operational procedures to optimize the network operation and cost-effectiveness. The upgrade of the network is based on optimizing the existing monitoring network using the geostatistical method of kriging and GIS. In this approach, the estimation variance is used as criteria in the design process, and variance reduction is used as a measure of network performance. Variance reduction involved a methodical search for the number and locations of sampling sites that minimize the variance of estimation error of the state variable in the aquifer domain. The search stops when adding new locations does not have a significant impact on reducing the variance, meaning that adding more observation points would not provide significant information and would not decrease uncertainty. The uncertainty criteria are coupled with the constraints of landmass availability and government land ownership, and are further supported by an expert judgment on the aquifer geometry, flow directions, and groundwater limit. The main recommendations for upgrading and enhancing the cost-effectiveness of the groundwater monitoring system in Bahrain and for maximizing its obtained information are as follows: 1) groundwater level: installation of a wireless groundwater monitoring system for water levels and adding a number of piezometers in the up-gradient parts of the aquifer; 2) groundwater quality: internalize the cost of monitoring on groundwater consumers through users self-reporting by all industrial and commercial wells, and to add a number of farmers wells to the network; and 3) data management: establish a dedicated management information system for groundwater monitoring data. Furthermore, it is recommended to optimize the groundwater monitoring network temporally, i.e., sampling frequency.

ABSTRACT. Groundwater is a critical water resource worldwide, used for a range of purposes and requiring active management to strike an appropriate balance between economic, environmental and social outcomes. In addition, groundwater is an indicator of climate variability and human impacts on the environment.

In Australia, groundwater is a significant component of the agricultural, mining and energy sectors, as well as being a source for drinking water for many communities. Balancing outcomes through government groundwater management frameworks is complex and is often hindered by incomplete/ timely delivery of data.

Accurate water-related data is sparse across much of rural and regional Australia and water authorities are facing the challenge of having to monitor and manage water with out-of-date and incomplete information. Providing the coverage and timeliness of water data that stakeholders increasingly seek in a constrained resource environment is a key challenge for the South Australian Government Department of Water and Environment (DEW). DEW is responsible for the operation and management of an extensive network of groundwater monitoring bores, and despite having invested significant R&D in reliable, standardised ‘plug and play’ solutions for the instrumentation and telecommunications of its water monitoring sites, only 6% of their 3500 groundwater bores monitored are currently instrumented. This means that data collection is infrequent and expensive, particularly in harsh and remote locations which require field visits. Currently, the department uses data loggers, which can supports high frequency of data measurement (e.g. hourly) but due to remoteness of many sites and lack of terrestrial data transmission networks, data from loggers can only be collected infrequently – often only once or twice a year for remote sites.

The SIG Water project, described in this paper, was aimed at providing an affordable and reliable solution, to enable DEW to improve the serviceability in providing water information at optimal time intervals for users of the data. The key benefit of SIGWater lie in the ability to access the data reliably and almost as it is measured in the remote location, as well as a significant cost saving over current in-field data collection practice.

The SIG Water project developed a pilot to demonstrate the use of an Internet-of-Things (IoT) satellite telecommunications solution as an end-to-end cost-effective means to transmit and aggregate, in near real time, automatically collected information from ground water bores in rural and regional areas. To this end, the project tested the technical feasibility, reliability and cost-effectiveness of deploying an end-to-end IoT satcoms solution in a remote and harsh environment – including evaluating, procuring and deploying sensor technologies to measure groundwater levels, pressure, salinity, temperature and flow in groundwater stations/bores and assessing the feasibility of these to operate autonomously. The pilot covered a total of 73 sites, across the Great Artesian Basin and within the Eyre Peninsula in South Australia.

ABSTRACT. For many years, background leakage has been an unseen problem costing money and wasting resource. Acquiring, treating and transporting water uses significant amounts of energy. The water lost through leakages has been sourced, treated and pumped at least once to get into our supply systems thereby increasing carbon emissions via its electricity drain and also threatening water security. Many water companies operate to an economic level of leakage which simply put means, if it costs more to fix it than it costs to waste it, then the leakage is an acceptable loss. Using L-Band SAR data, ASTERRA processes the satellite data with patented and proven technology to locate leaks and helps to shift the dial on this economic argument benefiting companies bottom line and the environment. More broadly, this allows utilities to shift focus from new infrastructure to investment in existing infrastructure. ASTERRA’s Recover product, utilizes radar signals taken from a SAR satellite to scan the area of interest and collect the resulting reflected signals. These signals are analysed and processed to identify specific indicators of wet soil saturated with potable water, screening out the signal noise and other interferences. The result is a map showing likely leak locations (LLLs). The Recover analysis typically highlights 5-10% of the entire system length, and only these locations where there is expected to be a leak are inspected by field leak detection teams. Thus, the time and resource cost of leak detection is much lower than traditional leak detection approaches (e.g., full-system, random, systematic, or block map). This presentation will discuss a specific ASTERRA customer case study within the Middle East, the lost water identified and recovered, and report on the value proposition to the utility and customer. The presentation will present benchmark data from other projects to compare results achieved using the Recover product.

ABSTRACT. Existing Variable Rate Irrigation (VRI) practices use soil electrical conductivity, historical yields, and topographic maps to delineate variable rate zones. However, these methods are not conducive to tracking within season variability in crop water demands. With increasing remote sensing data availability, in-season maps of crop coefficients and evapotranspiration (ET) may help inform variable rate irrigation schedules. Although, the amount of spatial and temporal variation in crop coefficients at the sub-field level has not been widely researched. This study aims to compare subfield ET estimates from two remote sensing platforms and quantify spatial and temporal variations in sub-field level ET. Vegetation indices and reference ET data were collected at Kansas State University’s Southwest Research Extension Center (SWREC) and two Water Technology Farms during the 2020 corn growing season. Weekly maps of the normalized difference vegetation index (NDVI) and the soil-adjusted vegetation index (SAVI) from manned aerial imagery were combined with empirical equations to estimate both basal and combined crop coefficients at a 1-meter resolution. These coefficients were combined with local reference ET estimates, aggregated to a 30-meter resolution, and compared to the Landsat Provisional Actual Evapotranspiration dataset. Finally, actual ET estimates from aerial images were aggregated using K-means clustering and stationary variable speed zones to determine if there is enough variation in actual ET at the sub-field level to build variable rate irrigation schedules. An equivalence test demonstrated that the aerial imagery and Landsat data sources produce significantly different crop coefficient estimates. However, the two datasets were moderately correlated with Pearson’s product-moment correlation coefficients ranging from -0.95 at the SWREC to 0.63 and 0.86 at the two Water Technology Farms. Both the aerial imaging and Landsat datasets showed high variability in crop coefficients during the first 5-6 weeks after emergence, with these coefficients becoming more spatially uniform later in the growing season. These crop coefficients may help irrigators make more informed irrigation management decisions during the growing season. However, more research is needed to validate these remotely sensed ET estimates and integrate them into an irrigation decision support system.

ABSTRACT. Actual evapotranspiration (AET) is generally the largest ‘consumptive’ component in the catchment water-balance in arid and semi-arid basins. In many agricultural basins, water resource use is on an unsustainable trajectory because of overuse of surface water and groundwater for irrigation. The impact on water resources of increased irrigation and concurrent AET at policy-relevant scales –from farm scale through catchment to regional scale–has been difficult to quantify. Satellite Remote Sensing (RS) at Landsat resolution and high-performance geostatistical cloud computing in Google Earth Engine (GEE) provide an opportunity to estimate AET at resolutions amenable for detailed modelling and decision making. In a Terrestrial Ecosystem Research Network (TERN) funded project using GEE infrastructure and its petabyte catalogue of satellite data, we developed a monthly Landsat-based (30 m) gap-free Australia-wide AET product using the CMRSET reflective remote sensing model. For this purpose, CMRSET was recalibrated using AET data from 30 flux towers representing most of the climates and land covers in Australia. Optimal parameters sets were obtained for Landsat, Sentinel-2, MODIS and VIIRs satellite products. MODIS CMRSET AET was evaluated using the water balance method in 638 unimpaired catchments covering again a wide range of climates and land covers in Australia, yielding a rRMSE of 0.24 and a R2 of 0.76. In addition, MODIS CMRSET AET estimates were benchmarked against more complex MODIS AET models, yielding similar or better results. The Landsat CMRSET implementation required processing of over 141,000 Landsat images totalling over 75 Tb. Through ‘blending’ with MODIS or VIIRS reflective data, the TERN CMRSET AET product provides gap-free analysis-ready data (‘good-to-go’ from a user-perspective). The Landsat-based AET estimates can be viewed in a purpose-built GEE app available at https://tern-landscapes.earthengine.app/view/cmrset-landsat-v22. The data can be freely accessed for user-defined points and polygons from this GEE app. For more details about the TERN AET product see https://www.tern.org.au/news-australia-wide-aet-data/. CMRSET’s is a straightforward vegetation-driven model which requires only reflective and meteorological data. Geo-modellers from numerous disciplines (e.g., hydrologists, climatologists, agronomists, ecologists) can now access the monthly 30 m AET data for any part of the Australia continent, and with GEE’s infrastructure, CMRSET can be implemented for any vegetated biome across the world.

ABSTRACT. The health and quality of our inland and coastal waterways are under profound threat due to increasing human activity and climate change, as well as the environmental impact from bushfire sediment, storm events, pollution, and contamination. Water is our most precious natural resource; in a country where drought, population pressure, and water shortage are significant features of our climate and landscape, the security of clean healthy freshwater resources and coastal waterways is critical to individuals, communities, industry, and the environment.

There is a unique opportunity to use space technologies to aid in monitoring and managing water resources, and harnessing the advantage of the global nature and vantage point that these offer. With this in mind, the AquaWatch Australia (AquaWatch) Mission has been developed. It responds to growing water quality issues, both in Australia and internationally, and aims to provide accurate and timely monitoring and management of water quality in aquatic ecosystems across Australia for government, water agencies, local communities, and industrial and commercial users, that enables decision makers to best plan, manage, and monitor aquatic resources and ecosystem health. The mission is being jointly undertaken by two leading space and science research organisations in Australia: the SmartSatCRC Cooperative Research Centre and CSIRO (Commonwealth Scientific and Industrial Research Organisation), as well as Australian state government departments, the Australian Bureau of Meteorology, Geoscience Australia and early research collaborators including the University of Queensland, UNSW Canberra, Curtin University, Frontier SI, Water Research Australia and SatDek.

The goal of AquaWatch Australia is to safeguard our freshwater and coastal resources through satellite technologies and innovate analysis and modelling.

AquaWatch is being designed to monitor all inland water bodies: lakes, farm dams, reservoirs, streams, rivers, coastal lagoons, estuaries and coastal waters and coral reefs within Australia. It will be tailored to meet the specific needs of Australia, supporting improved management and health of our precious water resources. The AquaWatch system will include Earth observation satellites designed to detect optical water quality and water body extent from space. The satellite images supplement data from a real-time in situ sensing network. Dedicated data analysis and water quality modelling provides a range of data points for increased situational awareness and supporting early detection or prediction of issues.

The range of parameters that will be detectable from space, and from the remote sensing network is still being determined. However, the current work to define AquaWatch focuses on the CEOS (2018) report: 'Feasibility Study for an Aquatic Ecosystem Earth Observing System', with special consideration to the types of water bodies and common issues found in Australia.

Although the initial concept deals with Australian needs, AquaWatch is expected to have a significant role in supporting management and health of water resources around the world.

ABSTRACT. The health of our inland waters and coastal environments is essential for maintaining safe water for drinking, for use by primary industries and for preserving our natural environments. However, with increasing demand on water use under climate change conditions, water quantity as well as water quality has deteriorated worldwide over the last decades. Intensive land use and associated nutrient loading, changes in natural flow regimes associated with climate change have led to more frequent blooms of harmful algae, rise in salinity, changed turbidity levels etc. Water from reservoirs is mainly used for drinking water, irrigation, stock needs, recreation, flood mitigation and/or hydroelectricity. This demonstrates the significant socio-economic impact that water quality issues might incur. Predicting water quality characteristics in a timely and accurate manner is an essential ingredient of proactive and informed decision making against risks related to degradation in water quality, like algal blooms. To keep track of current and future changes in water quality for large areas, it is necessary to adapt our monitoring, modelling and forecasting capabilities of water quality using advanced technology. This combines new in-situ sensor technology with large scale monitoring capabilities of Earth observation systems and physics-based machine learning algorithms.

In two complementary projects, the EU Horizon 2020 funded PrimeWater and the CSIRO AquaWatch Mission, we have taken significant steps forward in establishing pathways for better management of our water resources in the future. PrimeWater integrates state-of-the-art satellite technology and in-situ monitoring with advanced hydrological and water quality modelling into a powerful decision support system to achieve operational predictive models for water quality managers (here for algal blooms). While this is done on a case-by-case base, the AquaWatch Mission establishes a pathway to combine ground sensor data, satellite imagery and hydrodynamic models on a regional to continental scale to produce a range of value-added data products, delivered through online AquaWatch web services for use by water managers.

In this presentation, we will share our learning from two Australian case studies: Lake Hume, a large reservoir often plagued with frequent harmful algal bloom outbreaks, and the Melbourne Water wastewater lagoon system with regular algal blooms. To test a monitoring and forecasting service of toxic algal blooms, we collected bio-optical properties, stratification, and blue-green algae bloom formation by combining grab sampling, continuous in-situ measurements, remote sensing technology and modelling (hydrodynamic and algal growth). For the first time, we trialled a low-cost ex-situ HydraSpectra instrument, which exploits the spectral reflectance signals emanating from algal-dominated waters corresponding to Chlorophyll-a concentration and cell counts. An operational visualisation system and the use of data-driven algorithms will also be discussed. We finally are closer to large scale early warning and forecast capabilities of water quality by using the upcoming AquaWatch Mission tools, which can be tailored to the needs and use cases of water managers to make better decisions.

ABSTRACT. Climate change, rising sea levels, excessive pumping and seawater intrusion (SWI) pose major challenges to water resource management in coastal areas. Excessive pumping is considered a major cause of SWI into coastal aquifers and rising sea levels accelerates the intrusion. The combined effects of excessive pumping and rising sea levels make the problem worse and require more attention. Therefore, SWI due to excessive pumping and rising sea levels should be predicted and controlled to protect groundwater. In this study a coupled transient density-dependent finite element model is developed to investigate the effects of excessive pumping and rising sea levels on SWI in Gaza aquifer. Three scenarios are considered; excessive pumping, rising sea levels due to climate change and combination of the two. The results show that rising sea level has a significant effect on the intrusion of saline water. However, the combination of sea level rise and excessive pumping results in more intrusion and large amounts of freshwater in the Gaza aquifer could be polluted. To manage SWI into Gaza aquifer, three scenarios have been presented including; decreasing abstraction from the aquifer and using other sources of water such as desalination, increasing recharge to the aquifer using tertiary treated wastewater and combination of the two. The results revealed that using tertiary treated wastewater to increase the recharge to Gaza aquifer combined with decreasing the abstraction from the aquifer could help in protecting the aquifer from deterioration.

ABSTRACT. In this present study, an efficient material for adsorption of methyl violet in water was synthesized. This material was developed from zinc oxide nanoparticles synthesized via a simple and cost reasonable co-precipitation technique. The zinc oxide nanoparticles were then functionalized through covalent grafting onto synthesized pyrene ligand (1-(4-hydroxyphenyl)-4-phenyl-2,3-diazo butadiene) and employed for the removal of methyl violet (MV) from water. The synthesized materials were characterized with several instruments including; FTIR, EDX, SEM, XRD and TGA. The characterization results indicate that the pyrene ligand was successfully grafted onto ZnO NPs. This material showed high efficiency for the removal of methyl violet (MV) in all batch adsorption experiments and an excellent adsorption maximum capacity (31.5 mg/g) in comparison with other adsorbents previously employed for the removal of MV was obtained. Kinetics and isotherm studies indicate that the process for the removal of this contaminant using this new material proceeded via pseudo first order and Langmuir isotherm models respectively. These results indicate that this material can serve as alternate material to already established materials for the removal of recalcitrant organic contaminants from aqueous solutions.

ABSTRACT. This study was conducted in Hadejia Metroplis, geographically situated between latitude 120 13’ – 130 60’N and longitude 90 22’ – 11’00E. The topography of the area is dominated by Hadejia River which drained into Lake Chad. This area lies on the Northern-bank which of this river, which at some points is 1-2 metres above the surrounding plains including the town. Its climate is semi-arid in nature with a total rainfall range of 600 mm to 762 mm annually, while the Sudan Savannah vegetation type is dominant. A total of 20 sampling points were selected for the study, the groundwater samples were collected in triplicate and analyzed for physicochemical and trace metals values using standard methods .The results showed that concentration range of Mn, Cr, and Pb (0.33- 19.79, 0.09- 0.30 and 0.02- 2.99 mg/L respectively) were found to be slightly higher above the maximum permissible limit of Nigerian Standard for Drinking Water Quality and World Health Organization( 0.2, 0.05 and 0.01mg/L respectively) while Fe, Cu, and Zn concentrations are below or within the permissible limit (0.3, 1.0, and 3.0 mg/L respectively) in majority of the boreholes. The values for physicochemical variables EC, pH, Temp., TDS, T/Hardness, Ca, Mg, Cl, and NO3 were found to be below or within the permissible limits. Factor Analysis (FA) was used to investigate the origin of each water quality parameters and yielded five Varimax factors with 75.28% total variance respectively, indicating the major variations are related to anthropogenic activities and natural processes. Cluster analysis results grouped the 20 sampling points into five statistically significant clusters based on their similarities. Since the parameters Cr, Mn and Pb have significant loading factor and their spatial variability imply larger impacts on the groundwater quality, so it must be carefully and accurately mapped and those boreholes with high level of these metals should be closed, while new ones constructed. Further work is recommended to correlate the presence of high level of some of the trace metals with possible health implications/outbreak that is likely occurring or expected to occur.

ABSTRACT. The vadose zone underlying land sites allocated for MAR infiltration basins or recharge dams in arid countries is commonly explored for soil’s hydraulic properties (saturated conductivity, porosity, capillary parameters) at the stage of site selection, feasibility studies, and design of a hydraulic structure. Standard testing methods for unsaturated subsurface include core sampling, infiltration tests, and geophysical surveys, which are upscalable for homogeneous or layered soils (sediments-regolith). In some situations, however, the subsurface is interspersed by animal burrows (e.g., foxholes) and holes made by the roots of dead trees (e.g., ones extirpated by Gonu-Shaheen type cyclones). Such non-standard macropores do not have distinct footprints in the above-mentioned exploration techniques. For example, the hole can be away from a plume of seeped water generated by a double or tension-disk infiltrometer. Undetected and uncounted holes severely affect infiltration and deep percolation when the hydraulic structure is operational and the whole land area is ponded. In this abstract, we investigate the impact of such holes on steady-state, 2D, Darcian seepage from a horizontal soil surface, I1I2, which is either ponded (infiltration basin) or subject to an accretion flux. Water moves to a deep drainage layer I3I4 (Fig. 1a shows a vertical cross-section, one-half of the flow domain).

We use HYDRUS-2D (Šimůnek et al., 2018). We assume that the hole is long and its axis is perpendicular to the vertical plane of Fig. 1. A circle of a radius R is centered at a depth d > R under point I1, the origin of Cartesian coordinates I1xz. The hole is either empty or filled with water up to the level of the piezometric head ht =p+z, . The arc BM of the half-circle in Fig. 1 is a constant piezometric head boundary; if 0<h_t≤2R, the arc MA is a seepage face. Along the segment I1I2 we specify either a constant ponding piezometric (pressure) head p = pp or constant infiltration e=es. Annual rainfall values (e.g., 100 mm/year for Oman) of precipitation are amended by ET (redistribution of infiltrated moisture) and return irrigation inputs (if any) to get es. The boundary flux, qi, through I1I2 is qi=qin+qb, where qi and qb are the flow rates intercepted by the hole and by-passing it, respectively.

The two-branch separatrix SuSSb in Fig. 1 splits the whole flow domain into a through-flow zone on the left and a by-pass zone on the right of this divide. A stagnation point S is located somewhere: a) along AI1 for large ht, i.e., a subsurface emitter regime is realized (Kacimov et al., 2018), b) on BI4 ¬for ht = 0, or c) on the circumference, beneath point M for moderate-small ht (as in Fig. 1). Water exfiltrates from the saturated soil into the hole with the rate qin through a seepage face segment AM, where the pressure head p=0, and a constant total head segment MS. Water infiltrates back into the soil through MB with the rate qout.

ABSTRACT. January 8, 2022 The updated extended abstract is uploaded incorporating the comments by Reviewer 1. Reviewer 2 did not ask for any modifications. The authors are thankful to both reviewers for helping to improve the quality of the extended abstract.

ABSTRACT. In the arid and semi-arid regions, flash floods are among the most destructive natural hazards in terms of human losses and economic damages. To reduce the risk of damage and loss of life from flash floods to wadi’s residents, the priority is to develop mitigation strategies. On the other hand, flash floodwater can be an important source of water in arid environments. Unfortunately, there is often a lack of data on key hydrological processes in arid areas. The main focus of this study is to develop a new approach that will help in assessing various flood mitigation scenarios in three wadi case studies from Egypt and Oman. Computation is carried out using sophisticated techniques where remote sensing data is used along with hydrological/hydraulic models to simulate several flash flood events at the studied case studies and to compare between different mitigation measures options. The adopted mitigation strategies are based on a set of concentrated and distributed dams with and without bottom outlets. The results show that a group of distributed dams could outperform a single concentrated dam when flood mitigation and water resources management aspects are considered. However, the concentrated dam scenario may have advantages due to the cost of construction and operations. Having bottom outlets secure better environmental and maintenance conditions in the proposed flood mitigation scenarios.

ABSTRACT. Flooding events cause economic, social and environmental damage and lives loss. Flood’s magnitude and its consequences are aggravated by human activities in many circumstances such as urbanization. Wadi Ain Ghazal in Amman city has serious flood problems. The purpose of this study was to assess flood hazard and risk in Wadi Ain Ghazal using GIS-Based Spatial Multi Criteria Approach given that flood hazard and risk maps are effective tools for reducing flood damage. Six flood causative factors (elevation, slope, drainage density, land use land cover, manholes, and rainfall) and three elements at risk (population, roads and cropland) were processed and assessed in GIS environment. The Fuzzy Analytic Hierarchy Process approach was used for weighing the factors and combined in a weighted overlay operation to determine the flood hazard and risk. The major findings of the study revealed that most of the lowlands in the downstream part of the sub-basin that is located in the eastern and southwestern parts are within high to very high flood hazard and flood risk level with area coverage close to 27% and 27.5% respectively. The risk assessment of flood and in particular the critical facilities (e.g. hospitals) shed light on the necessary measures to be taken by the concerned authorities to formulate their development strategies accordingly.

ABSTRACT. Fog is a visible aerosol consisting of tiny water droplets suspended in the air near the Earth's surface, and can be considered a type of low-lying cloud which is heavily influenced by nearby bodies of water, topography, and wind conditions. Due to the abundance of Fog on earth throughout the year, its harvesting has been considered an objective of many countries to compensate for the scarcity of water in most of their inhabited areas. Usually, large vertical meshes are used to help in the condensation of water droplets, hence their collection and usage. In the current study, a galvanized aluminum mesh with a microscopic surface architecture has been used for fog harvesting. The effect of chemically functionalizing their surfaces with a composite of hydrophilic and hydrophobic components on the efficiency of fog harvesting is described. Al meshes were functionalized with poly(methyl methacrylate) (PMMA) as a hydrophobic polymer, containing titanium oxide (TiO2) nanoparticles, as a hydrophilic filler. The chemically-functionalized galvanized Al meshes were characterized for their composition, surface hydrophilicity and morphology. These characteristics were related to their efficiency of fog harvesting. Our preliminary estimates of fog harvesting indicate a sustainable approach of water collecting with a pronounced efficiency that is overriding what has been shown in the literature.

ABSTRACT. The impact of urban floods represents a challenge for several cities around the world. Sharjah city in the United Arab Emirates experiences significant challenges of urban floods during and after raining evens, which can be linked to the recent cloud-seeding operations conducted in the country. This study assessed IDF curves of three meteorological stations in Sharjah emirate before and after implanting the cloud-seeding operations that started in 2010. Hourly rainfall data related to three stations, namely Sharjah Airport, Al Dhaid, and Mleiha provided by the National Center of Meteorology were used in the assessment. The developed IDF curves showed a significant increase in the values for all stations after implanting cloud-seeding operations. In addition, the estimated mean rainfall intensities for the three stations were also much higher for the cloudseeded years than for the period without cloudseeding. The study suggests updating the IDF curves values on the national level and providing them for all related government departments and consultancy firms to be considered in designing, assessing, and updating storm drainage networks.

ABSTRACT. Saltwater intrusion (SWI) in coastal aquifers is a well-documented phenomenon in many parts of the world, often manifesting as a saline wedge that can extend inland below a freshwater-saturated aquifer. This phenomenon is further complicated in some coastal aquifers, affected by tidal processes, by the occurrence of an intertidal saltwater cell (ISC); this forms in the intertidal zone when saltwater infiltrates down during high tides to impact the uppermost interval of fresh groundwater. When such coastal aquifers are pumped, saltwater can be drawn into the area of abstraction and into the well from both the DSW and ISC. Electrical resistivity imagining (ERI) provides a non-invasive geophysical technique, often used to detect and monitor subsurface structures, based on differences in their electrical properties. The change in resistivity, due to the density difference in fresh and salt water, means that this tool also represents a solution to characterising and monitoring the movement of a saltwater intrusion within an aquifer. This research will present the initial findings of a study of near-shore SWI in a coastal Northern Irish sand aquifer. It will demonstrate the values of a novel ERI system in pumping and passive gradient situations, allowing the development of a four-dimensional picture of saltwater behaviour in a tidal setting with near-real time data acquisition and interpretation using the Internet of Things. In concert with downhole level and discharge water quality measurements, this four-dimensional approach has enabled the rapid characterisation and assessment of a coastal aquifer with respect to water abstraction. Presented will be the results and comparisons with these different data sources, showing, through their corroboration, that ERI alone is a reliable source of information in assisting with the decision-making processes required to obtain freshwater from a nearshore aquifer.

ABSTRACT. Drought is a complex phenomenon caused by a lack of precipitation that affects water resources and human society. Traditional methods to assess groundwater drought events are hindered due to sparse groundwater observations on a spatio-temporal scale. These groundwater drought events are not well studied in the study area of the Indus basin irrigation system (IBIS) holistically. This study applied two machine learning models (Extreme Gradient Boosting and artificial neural network) on the training datasets of Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage (TWS) and groundwater storage (GWS) data to improve resolution to 0.25° from 1°. The Extreme Gradient Boosting (XGBoost) model outperformed the artificial neural network (ANN) model and results showed Pearson correlation (R) (0.99), Nash Sutcliff Efficiency (NSE) (0.99), Root Mean Square Error (RMSE) (5.22 mm), and Mean Absolute error (MAE) (2.75 mm). The standardized groundwater index (SGI) was calculated by normalizing XGBoost-downscaled GWS. The trend characteristics, the temporal evolution, and spatial distribution of SGI were analyzed across the IBIS from 2003 to 2016. The XGBoost-downscaled GWS revealed a good correlation with in situ GWS showing an R of 0.67. The accumulated standardized precipitation evapotranspiration index (SPEI) with the time of 1, 3, and 6 months, and self-calibrated palmer drought severity index (sc-PDSI) were used to validate SGI. The findings have demonstrated that SGI has comparable drought patterns to SPEI-3 and SPEI-6 and sc-PDSI. The proposed framework can serve as a useful tool for drought monitoring and a better understanding of extreme hydroclimatic conditions in the IBIS and other similar climatic regions.

ABSTRACT. An optimization model is developed for planning regional wastewater systems based upon minimizing total costs of sewer layout and wastewater treatment plants (WWTP) locations considering uncertainly of treatment capacity. In this paper, the model is to minimize the total costs by considering uncertainty in such way that waste to be treated does not exceed the treatment capacity with a certain percentage of reliability. The model is formulated as chance-constrained approach, which is known to solve optimization problems under various uncertainties. The model is developed using Mixed-Integer Nonlinear Programming (MINLP) in the General Algebraic Modeling System (GAMS) program and applied to a simple example using different reliability percentages 60% to 95%. The results of a simple example show that the system's total costs and layout are the same as using 60% to 75% reliability. However, once the value of reliability is over 80%, the layout and total costs of the system would be changed to be higher.

ABSTRACT. Dubai is categorized as an arid region, and over the years with the increase of population, the built-up area is also increasing. Due to the specific type of dry climate, rainfall is very scarce. The rainfall event mainly occurs between January and March and intensity of these rainfall is so high that it causes floods. Flooding is the most devastating types of hydrological events which are triggered by excess precipitation. The objective of this study was to estimate runoff as a result of March 2016 rainfall in Dubai. The precipitation from Global Precipitation Measurement (GPM) was studied using HEC-HMS. DEM was used to delineate subbains for Dubai. SCS Curve Number was used as a loss method in the HEC-HMS. Since the subbains differs in their land use characteristics, therefore weighted curve number was calculated for each subbasin. The land use type was obtained from LULC map. The results showed that highest flooding of 2802 m3 in subbasin 3 which is largest subbasin having an area of 330 km2. The results also depicted that subbasin having larger area produce highest runoff. These results were validated with Rational Method and previous studies. The comparison of peak discharge from HEC-HMS with Rational Method showed R2 of 0.88. The peak discharge was also consistent with previous studies of UAE and Egypt. Since there are no active flow gauges in Dubai, these studies are important for stakeholders in their decision making for future development projects.

ABSTRACT. As more cities experience increased water stress and high demand, the evaluation of household water consumption patterns that underpin peak demand are increasingly forming the basis of numerous water studies. This paper presents a household water consumption framework that water utilities can use to determine households probable peak demand pattern and to predict the amount of water they are likely to consume per day. In previous studies, the authors used smart meter data, a water consumption survey, "Acorn" and occupancy data from 10,000 homes to track households' unique water consumption patterns and the many factors that affect them. Four distinct clusters of peak water demand patterns were identified, namely, "Evening Peak" (EP), "Late Morning Peak" (LM), "Early Morning Peak" (EM) and "Multiple Peaks" (MP). This framework is developed by employing a set of data-driven metrics from the previous studies to classify households into hierarchical water consumption clusters and to infer the amount of water they are likely to consume daily.

ABSTRACT. Lack of sufficient rainfall data has been a common problem hampering water resource planning in many arid regions that have sparse weather monitoring networks. Satellite rainfall data must be validated first before incorporating it in drought monitoring studies. This research presents the first validation study in Syria for the Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) product within situ rainfall data. The CHIRPS has a high spatial resolution (0.05°) and has been validated globally in multiple basins. The Damascus basin is located in the southwestern part of Syria and is dominated by a semiarid climate in the east and a Mediterranean climate in the west. The analysis in this research was performed across multiple temporal scales (monthly, seasonal, wet, dry , yearly) within three climate regions (Mediterranean, semiarid, and arid). Eight rain gauges were used in the validation procedure to assess how accurate the CHIRPS dataset was in estimating rainfall quantities between 2010–2021. Statistical analysis applied in this evaluation include the Pearson correlation coefficient (r), mean absolute error (MAE), mean error (ME), and percentage bias (PBIAS). Results show that CHIRPS data correlate well with observations on a monthly basis for all stations and have an average correlation coefficient of 0.76 but tend to overestimate low and medium rainfall events while underestimating high rainfall events (>50 mm/month).On the other hand, CHIRPS tended to behave differently across the seasons. A stronger correlation was found in wet seasons (winter and fall), while in dry seasons (spring and summer), the correlation was less, but CHIRPS was more accurate in detecting rainfall events. The wet period (October–March) is vital in drought monitoring; therefore, CHIRPS’s ability to accurately estimate this period’s rainfall quantities is crucial. Despite this product's tendency to overestimate the observations quantities, the overestimation ratio differs by basin regions. During the wet period , the PBIAS is less (11.1) comparing to the dry period (April - September) where the overestimation Higher. Yearly results showed poor performance in estimating rainfall quantities. Data validation showed that CHIRPS data could be applicable on a monthly scale during both wet and dry seasons, which could aid water resource planning, especially drought assessments. These results may serve as a useful reference to water managers as well as policy and decision makers in Syria since the basin currently relies on a sparse weather monitoring network for its observed rainfall data, which are of the utmost importance in water resources planning.

ABSTRACT. Hydrologic models incur structural, measurement, and parametric uncertainties resulting from errors in the mathematical representation of hydrologic processes, measurement errors, and limited amount of data, respectively. Separating structural and measurement uncertainties continues to be a key challenge for hydrologists. Estimating structural uncertainty may be possible if measurement uncertainty can be estimated independent of the modeling exercise, i.e., before calibration. In this study, the Random Forest (RF) method was used to estimate the measurement uncertainty due to errors in rainfall and streamflow measurements by providing limits-of-acceptability (LOA). Experiments with synthetic data demonstrated the efficacy of this method. Data from the Upper Mississippi River basin, Maumee River basin, and Ohio River basin were used to calibrate and test the RF model. Uncertainty bounds obtained by RF were shown to likely capture measurement uncertainties in streamflow measurement and rainfall as well, thus suggesting the potential of RF for constructing meaningful LOA bounds, and separating structural and measurement uncertainties in hydrologic modeling.

ABSTRACT. Flash floods in arid regions are typically a result of infrequent rain events characterized by a high spatial heterogeneity. Adjacent drainage basins or even adjacent channels within a single basin may differ significantly and unpredictably in the frequency of floods per year. Monitoring flash floods by hydrometric stations and water level measurements is limited to one or very few points for an entire drainage basin, neglecting the smaller tributaries within the basins. Consequentially there is a lack of continuous spatial information on the spatial distribution and frequencies of the flash floods, which limit our understanding of catchment and regional hydrological processes. In order to monitor and study the spatial dynamics of the active channels within the drainage basin or an entire region, a full surface cover with high spatial and temporal resolution is required. Remote sensing is a powerful tool to meet these requirements. The objective of this research is to develop a remote sensing technique to monitor flash floods in arid regions. More specifically, we aim to define the post-flood spectral signal that can be used to extract the flow extent. Flood mapping and detection of water bodies use spectral indices of surface water. However due to the short duration of flash floods, which are typical to arid ephemeral streams (wadis), a post- flood index must be applied. We offer a novel approach that detects the extent of floods by the soil moisture signal that remains after the flood ends. This can be achieved by applying short wave infra red (SWIR) spectral indices that are sensitive to soil moisture. For ground truth analysis, flow events records were collected from 13 hydrometric station of the Israel Water Authority (IWA), located in several main channels in the Negev Desert. The data include 23 storm events, that occurred in three successive hydrological seasons from 2017 to 2020. In each station, three to twelve flow events were recorded during this period, providing a total of 111 recorded flow events. All ground data of floods was related to Sentinel-2 images. The time lag between the end of the flow and the image time acquisition was calculated. The results indicate a high signal of flood extent when using change detection of SWIR spectral indices such as MNDWI and LSWI indices two days after the flood. The LSWI and MNDWI indices may be used in arid regions to detect flash-floods distribution and frequencies. We found that the time lag between the end of a flood and the image capturing, as well as max discharge, are two key parameters that impact the index ability to detect the floods.

Systematic monitoring of flashfloods by remote sensing in arid regions can provide essential data for validating models predicting flash floods and disaster risk management as well as for infrastructure planning, drainage management and river rehabilitation.

ABSTRACT. Technological advancements made the development and deployment of wireless sensor networks feasible. These networks were utilized in this research to evaluate the need for high-resolution rain measurement. The variability of the precipitation amounts was studied, in addition to its effect on the rainfall- runoff predictions in semi-arid regions. Results indicated that there is a statistical difference between the average daily precipitations reported within a sub watershed with a diameter of as low as 5 km. These differences can be as high as 62%. The same statistical difference was noted even when a comparison was done between the official records and an average of several gaging stations calculated using either the arithmetic mean approach, or the Thiessen polygon approach. Runoff predictions using the HEC-HMS model clearly demonstrated the effect of the variability in rainfall on runoff. Utilizing the wireless sensor networks for accurate capture of spatially varied precipitation patterns is highly recommended to accurately capture the system dynamics.

ABSTRACT. The extraction of surface water bodies from high-resolution remote sensing (HRRS) imagery has become an essential approach to acquiring vector layers. Several strategies, technologies, and methods were developed to delineate water bodies from remote sensing imagery varying in spatial, spectral, and temporal characteristics. This study puts forward an intuitive approach to extracting the water bodies from high-resolution drones and satellite imagery using an integrated deep learning method to GIS modeling in Dubai Emirate. In this study, training data was extracted first. Next an advanced deep learning model for object detection is introduced. Then, the deployment of this model in multiple areas across Dubai Emirate is comprehensively evaluated, including recognition, detection, classification, counting, and quality assessment. Finally, recommendations and limitations to take into consideration are summarized. The Evaluation tests performed paralleling the generated results to the reference data suggest that higher accuracy for water extraction is accomplished from the high-resolution images than traditional approaches such as machine learning (Supervised classification) and photo interpretation. Overall, the average overall accuracy reached 98% in urban areas while it registered 99% in rural areas, respectively. This novel approach offers great opportunities for the Geographic Information Systems Centre (GISC) at Dubai Municipality, under multiple land-use scenarios, to shrink the heavy amount of expensive human labor involved in editing the records through photo-interpretation or field visits or other manual techniques.

ABSTRACT. The region of Middle East and North Africa (MENA) is water scarce. It is predicted that water scarcity will increase with several drivers including population growth and its related food demand. Moreover, the region is exposing to frequent, severe and prolonged extreme events -droughts and floods- aggravated with climate change. The combination of these drivers and uncertainties aggravate the risk of increasing gaps between demand and water availability, groundwater overexploitation impacts and degradation in the quality. Water accounting (WA) and Water Governance Analysis (WGA) are complementary and provide a comprehensive information related to hydrological processes and water consumption for better communication, policy, and decision-making in a geographical domain. This paper, hence, reviews the implementation of WA and WGA framework and lessons learned gained from practice in some of MENA countries. It offers an approach to inform strategic planning for sustainable water use and trade-off decisions for the nexus water-food-energy-climate change. The way forward will be also discussed.

ABSTRACT. Drinking water is primarily supplied from groundwater resources. However, groundwater wells within 20 km radius from airports have been frequently contaminated by per- and polyfluoroalkyl substances (PFAS) due to infiltrated aqueous film-forming foams (AFFF) used at firefighting training sites. Various point and non-point sources have been suspected as primary sources of PFAS in groundwater. The high diversity of PFAS in surface charge, structure, and applications led to the complication of their detection and characterizations in water resources. However, most of the analytical instruments have certain limitations for the detection of PFASs at the molecular level. The unprecedented capability of ultrahigh-resolution Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) compared to other analytical instruments has further expanded the characterizing the complex PFAS contaminations of groundwater at the molecular level. Here, we collected samples from groundwater wells near three airports with other suspected external sources of PFAS. After extraction, the samples were analyzed in negative ion electrospray mode by the FT-ICR MS at the National High Magnetic Field Laboratory, Florida, USA. FT-ICR MS analysis allowed the characterization of complex PFAS-impacted matrices at the molecular level. Chemical profiling resulted in successful discrimination between PFAS sources, including AFFF application and wastewater treatment plant effluent. Short-chain (<C8) PFASs were detected in higher abundance compared to long-chain (C ≥ 8) PFASs. Statistical differences between identified PFASs in groundwater wells led to confident source separation and clustering the identical datasets of PFAS species. The commonality was approximately two times higher between airport wells and residential wells compared to the effluent of the wastewater treatment plant and the residential wells.

ABSTRACT. Trihalomethanes (i.e., chloroform, bromodichloromethane, dibromochloromethane and bromoform) considered toxic compounds to humans. The objective of this study was to assess the formation of trihalomethane species in two different synthetic drinking water samples prepared in the laboratory. The synthetic water samples were produced by blending desalinated water with groundwater using two typical blending ratios utilized in the drinking water production facility: 97.1% desalinated water, 2.9% groundwater; 85.0% desalinated water, and 15% groundwater. Simulated distribution system trihalomethane tests were carried out to assess the formation of trihalomethane species. The results showed that bromoform in both tests was the dominant trihalomethane species. The formation of trihalomethane species in the synthetic drinking water that comprised 15% groundwater was higher than that in the synthetic drinking water samples that comprised 2.9% groundwater. The study revealed that in the process of the blending of groundwater with desalinated water, during the production of drinking water, the higher the amount of groundwater utilized to produce the drinking water, the more bromide and organics existed in the finished water. This resulted in the formation of more brominated trihalomethanes in the finished water because of the water chlorination process.

ABSTRACT. While drinking water is known to create significant health risk in arsenic hazard areas, the role of exposure to arsenic through food intake is less well understood, including the impact of food trade. Using the best available datasets on crop production, irrigation, groundwater arsenic hazard, and international crop trade flows, we estimate that globally 17.2% of irrigated harvested area (or 45.2 million hectares) of 42 main crops are grown in arsenic hazard areas, contributing 19.7% of total irrigated crop production, or 418 million metric tons (MMT) per year of these crops by mass. Two-thirds of this area is dedicated to the major staple crops of rice, wheat, and maize (RWM) and produces 158 MMT per year of RWM, which is 8.0% of the total RWM production and 18% of irrigated production. More than 25% of RWM consumed in the South Asian countries of India, Pakistan, and Bangladesh, where both arsenic hazard and degree of groundwater irrigation are high, originate from arsenic hazard areas. Exposure to arsenic risk from crops also comes from international trade, with 10.6% of rice, 2.4% of wheat, and 4.1% of maize trade flows coming from production in hazard areas. Trade plays a critical role in redistributing risk, with the greatest exposure risk borne by countries with a high dependence on food imports, particularly in the Middle East and small island nations for which all arsenic risk in crops is imported. Intensifying climate variability and population growth may increase reliance on groundwater irrigation, including in arsenic hazard areas. Results show that RWM harvested area could increase by 54.1 million hectares (179% increase over current risk area), predominantly in South and Southeast Asia. This calls for the need to better understand the relative risk of arsenic exposure through food intake, considering the influence of growing trade and increased groundwater reliance for crop production

we identify 23 high-risk countries with a combined population of ~1.5 billion people that are potentially exposed to high arsenic intake from staple crops of wheat, maize, and in particular rice (92% of total risk). Greater arsenic risk exists where there are high levels of domestic production and consumption, e.g. South Asia, or where there is a high dependence on food imports, e.g. Middle East and small island states. Health risk due to arsenic exposure via food and food trade is of increasing importance due to population growth as well as intensifying climate variability, both of which will result in further reliance on groundwater, including areas naturally contaminated with arsenic.

ABSTRACT. Seawater intrusion (SWI) is a major threat to the sustainability of groundwater resources in coastal regions. This problem is exacerbated in arid coastal aquifers. Optimal sustainable management of seawater intrusion is needed to protect the groundwater resources, however, the management model, which is based on variable-density groundwater flow and mass transport process equations, is too complex and time-consuming. Furthermore, its optimization requires several calls to this simulation model, which makes the process very challenging and computationally expensive. This paper presents a study on the use of artificial recharge through an infiltration pond to prevent saltwater intrusion. To reduce the computational burden, a surrogate-assisted simulation-optimization methodology is developed, based on a constrained multiobjective Bayesian optimization (BO) algorithm. BO is efficient for optimizing computationally expensive problems with a limited number of iterations, as it performs local and global searches. BO builds surrogate models using a Bayesian machine learning method, Gaussian process regression, to replace the high fidelity simulation model, then an acquisition function is used to guide where to sample. The proposed methodology is applied to Wadi Ham aquifer in the United Arab Emirates to determine the optimal location, and volume of the infiltration pond, and to minimize the total cost and the average intrusion length while satisfying the water demand requirements. The results indicate that this optimization methodology could locate the region of feasible solutions with a limited computational effort. This proves its applicability to solve real-world coastal aquifer management problems. A saltwater repulsion of 60% from its initial intrusion length was achieved by the end of the management period, protecting the pumping fields from salinization.

ABSTRACT. High saline brine is the major effluent generated by the seawater or brackish water desalination plants and petroleum industries. Brine is a growing global problem and Middle East countries contribute more than half to the world’s total brine production. Brine volume is progressively increasing over the years due to the expansion of desalination plants as well as oil exploration and production activities, and, thus, the future of those activities will face significant challenges in Kuwait. The injection of brine back into sea is commonly adopted economical process, however, it has adverse effect on environment and marine ecosystems. The brine management using the emerging membrane distillation (MD) technology is gaining more interest among the research community due to ease of the technology to integrate with the solar or waste heat energy sources. MD is beneficial since it can be integrated with the existing desalination technologies like reverse osmosis (RO) and multistage flash (MSF) for the higher recovery of pure water from the brine solutions. In this study, the brackish water brine treatment efficiency is evaluated using the newly fabricated polypropylene (PP) based nanocomposite membranes. The surfaces of PP membranes were made more hydrophobic by coating with the octadecyl dihydrogen phosphate -CaCO3 and hydrophobic silica nanoparticles. The increased flux with the increase in temperature from 70‒80ºC was much sharper for all the coated PP membranes than the neat PP membrane. The MD process demonstrated its efficiency to extract freshwater from the brine stream with a starting TDS of ~42000 ppm. A sharp increase in flux above 40 L/m2h at 80ºC was due to the generation of higher water vapors and the resistance offered by the nanoparticles toward the penetration of water molecules into the membrane pores. The permeate TDS of all the coated PP-based membranes was within the range of 130‒160 ppm.

ABSTRACT. The recent estimates indicated that under the business-as-usual scenario, the remaining fresh groundwater resources in UAE are very limited and its lifespan is very short. Despite the fact that this is a general conclusion, there is a crucial need to deal with groundwater resources differently in each area. The necessary regulations to change the practice and to provide water based on the crop water requirements should be implemented. It is recommended that fresh groundwater should not be used for new agricultural development. On the other side, brackish water is abundant if compared to fresh groundwater. Brackish groundwater reserve with groundwater salinity of less than 15,000 mg/l is around 200 BCM. This type of water should be considered a precious water resource and should be used for agriculture development with necessary precautions. Based on the groundwater reserve, total salinity, distance to existing farms (pumping wells), the ratio of the present saturated thickness/max saturated thickness, and remaining lifetime, the groundwater conditions in the farming areas were divided into six groundwater potential zones (GWPZs).

ABSTRACT. The sustainable use and management of groundwater can benefit from improvements to both qualitative and quantitative groundwater vulnerability mapping methods for a variety of hydrogeologic systems, especially in highly complex and dynamic karst aquifers. Qualitative vulnerability mapping methods in karst aquifers rely on key factors in the hydrological compartments, assigned different weights according to their estimated influence on groundwater resilience to contamination. Here in this quantitative study, an integrated calibrated and validated numerical groundwater model of a karst catchment area (El Assal Spring- Lebanon) is used to evaluate the impact of model parameters on recharge and spring discharge and identify the most important parameters that control the intrinsic vulnerability of the system. Both the model sensitivity and the ranking of parameters are evaluated using an automatic calibration tool for local sensitivity analysis in addition to a variance-based local sensitivity assessment of model output time-series to various model parameters for two consecutive years (2016-2017). The influence of each parameter was normalized to estimate standardized weights for each of the process-based key-controlling parameters. Findings indicate greatest model sensitivity to 1) soil, 2) fast infiltration (bypass function) typical of karst aquifers, 3) climatic parameters (precipitation, melting temperature, and degree-day coefficient), and 4) aquifer hydraulic properties, which are parameters that play a major role in groundwater vulnerability inducing a variation in spring hydrographs and recession. Other parameters play a less important role according to assigned weights proportional to their ranking. Additionally, the effect of slope and geomorphology was further investigated on discrete model cells. Based on the results, the weighting coefficients assigned to key vulnerability factors in the qualitative assessment methods can be reevaluated based on a process-based approach for the proper delineation of protection zones and the establishment of water protection guidelines. The conclusions and methods from this study have important implications to other groundwater vulnerability assessments and will assist groundwater managers and scientists toward the sustainable development in other climatic conditions and karst settings.

ABSTRACT. The European Water Framework Directive (WFD) and the Floods Directive (FD) provide the member states with a comprehensive framework for water basin management. To implement these directives, in the Oriental Alpes River District (DAO), North East of Italy, the river basin management plan RBMP and the flood risk management plan FRMP are prioritizing new innovative unstructural measures for water management and for assessing the flood risk focusing on prevention and preparedness, thus reducing the vulnerability and exposure of the exposed assets. Amongst those assets, water distribution and supply networks should be considered. Despite this, there is currently a lack of methodologies for a proper assessment of water networks inside the context of water management at the basin scale. To overcome this gap, the Basin District Authority of the DAO (AAWA) is exploring new innovative methodologies, such as the one being developed inside aqua3S Horizon 2020 European project (Enhancing Standardisation strategies to integrate innovative technologies for Safety and Security in existing water networks – call: H2020-SU-SEC-2018, coordinated by the Centre for Research and Technology Hellas). The aqua3S approach consists in combing novel technologies in water safety and security, aiming to standardise existing sensor technologies complemented by state-of-the-art detection mechanisms. aqua3S proposes an innovative integrated system for water management with a particular focus on water distribution and supply networks. The proposed solution is designed to offer a very effective detection system, by exploiting and combining open data sources to complement sensor measurements. The aqua3S approach it is expected to have relevant impacts in different aspects of the water management, both from a social and economic point of view.

ABSTRACT. In a context where the pressures exerted on aquatic environments and the water needs of populations continue to increase, to which are added the impacts of global changes, knowledge of low water flows is a major issue. Low flow is defined as a natural, seasonal phenomenon, generally resulting from a more or less long and more or less severe rain deficit, likely to vary in time and space and leading to a decrease in flow in the streams. The Oued El Abid watershed (BVOA) is a sub-basin of the Oum Er Rbia wadi (30,600 km2). The Oued El Abid is the most important tributary of the Oum Er Rbia, with an average annual flow of 32 m3 / sec. A maximum average flow rate of 77 m3 / sec. A minimum average flow of 10 m3 / sec (Regional Atlas region Tadla Azilal Morocco, 2015). The regime of this watercourse alternates between brutal floods and low flow supported by water from the karst hydrosystems of the central High Atlas. The objective of this study is to characterize the low water flow rates of the Oued El Abid (Upstream) watershed with a view to better management of the water resources of this basin. The methodology used consists of extracting the VCNs from the values extracted annually, according to a fixed period "d", these are moving averages, calculated from the average daily flows over several consecutive days. Monthly flow data from a single hydrometric station in our study area (Tizi Nisly) was used and covers the period from 1976 to 2018.

ABSTRACT. The city of Ovidiu is located north of Constanta, near the Poarta Albă - Midia Canal, Năvodari, and Mihail Kogălniceanu International Airport, and is traversed by the European route E60 (national road 2A). Geographically, it is located at 44º16'12" north latitude and 28º33'36" east longitude. The city opens to Lake Siutghiol, which is separated from the Black Sea by a sand cordon of about 300 meters, where the tourist resort Mamaia is located. Computational urban growth and computer hardware have enabled an unparalleled rise in the availability of information inputs to planners. The goal of this study is to examine the evolution of Ovidiu's coastline in recent years through the use of and comparison of two satellite photos from 2011 and 2021 that demonstrate the coastal area's fast growth. Additionally, we gathered data from the cities’ general urban plan elaborated in 2019, which reveals significant disparities between the surface area of the built-up area now inhabited and the surface area of the previous plan dated from 1999. The result was an increase in the urban area by 253.82 ha (23.68%) and also the population increased from 10461 inhabitants (2002) to 15620 inhabitants (2019).

ABSTRACT. Desalination is a highly energy intensive process, currently powered primarily with fossil fuel. So, using solar energy for desalination is one of the most promising applications of renewable energy.

In this study, a novel design of storing heat is presented. The principle of the design involves three steps: filling up a tank with sea water, storing and heating sea water for a day to a later time use and feeding a desalination unit with store hot sea water. The new technique for a solar powered a desalination plant, modified by removing the conventional brine heater. The brine heater is replaced with a solar energy unit consisting of two direct thermal storage tanks and a system of solar collectors. The brine that feeds the modified design is heated directly without the need to an intermediary fluid or a heat exchanger. The two storage tanks which alternate roles at each day provide a full day of hot brine that has been heated to the top brine temperature.

The new approach to thermal storage system as an alternative to the brine heater in a desalination plant is experimentally investigated, in order to quantify its performance.

The model is used for a case study located in Saudi Arabia, using the alternating tank design; the required solar collector area is 2.3 m2, which is significantly less than the area required by other designs in the literature. The case study results indicate a summer-time maximum TBT of 87 °C and distillate production of 3kg/day.

ABSTRACT. As the interest in Artificial Intelligence (AI) has been rising, the use of machine learning (ML) methods in the field of research is gaining prominence from the research community, especially in the field of groundwater. ML algorithms are of two types: supervised and unsupervised. In supervised ML methods, the model understands the pattern of training data and predict based on learning, for example deep-learning models helps to improve predictions in time-series data. ML algorithms has so far been applied successfully to groundwater potential mapping, modeling groundwater level changes, nitrate, and fluoride mapping. Application in mapping groundwater vulnerability has been studied through traditional DRASTIC (seven parameters: depth to water, recharge, aquifer media, soil media, topography, vadose zone, and hydraulic conductivity) method and compared with ML predictions. Model built using Random Forest, on these seven parameters, achieved 93% accuracy with Receiver Operating Characteristics (ROC) curve as 97.3%. An unsupervised ML model, DBSCAN, was applied to Radon-222 (222Rn) data and it resulted in two clusters, having 222Rn concentration lower and higher than 11.1 Bq/L. The cluster with higher 222Rn concentration could be either the presence of localized rocks and soil enriched with Uranium-238 or groundwater is impacted physically through faults where gaseous radon concentration escapes along the faults from its source. In addition to the numerical models, ML models has proved to be a good tool in the study of natural phenomena in groundwater.

ABSTRACT. The major use of groundwater in the arid region is irrigation, due to low rate of rainfall and extensive use of groundwater for irrigation and industrial purposes, major depletion of groundwater levels has been recorded in Abu Dhabi region of United Arab Emirates (UAE). This study focuses on the groundwater budgeting through MODFLOW tool using zonebudget from the year 2005 to 2017. There are almost 100.000 active groundwater wells in the emirate of Abu Dhabi. Initial results of modeling showed that in Abu Dhabi, except the eastern region (Al Ain) and western region (Liwa), there is a little change of 0.5 cm/year, or a total of 0.2 m, water level decline, recorded from 2005 to 2017. However, the eastern region of Al Ain has more than 50.000 groundwater wells and is considered to be the major abstraction zone in Abu Dhabi emirate. Total volume of groundwater decline in eastern Al Ain region, from 2005 to 2017, is estimated to be 2 km3. This decline can be associated with groundwater abstraction and movement of groundwater towards western region of the emirate, as Al Ain region has high elevation. Whereas an interesting pattern is observed near Hafeet mountain where an increase of 0.28 km3 is observed in the same period which could be from the eastern boundary of Al Ain (mountainous region), that act as the major recharge zone. Further investigation will be carried out to understand and evaluate components of recharge and abstraction involved in groundwater budgeting.

ABSTRACT. Managed Aquifer Recharge (MAR) represents a feasible technique for water storage in the subsurface during the times of excess water availability and recovery it during the times of water shortage/high demand (Dillon, 2005, 2009). However, aquifer storage and recovery (ASR as a type of MAR) processes, in particular, the mixing of the injected water with the native groundwater need to be fully understood and examined for each candidate geological site. ASR projects can help in the development of strategic freshwater reserves for possible use during emergency times. Oman is strategically working on implementing ASR projects to bank the excess of desalinated water and treated waste water in agricultural areas, especially, in the coastal zones (Ebrahim et al., 2015; Al-Maktoumi et al., 2016, 2020; El-Rawy et al., 2019). A real injection of treated wastewater into a coastal aquifer to act as a hydraulic barrier is practiced in Salalah (South of Oman) for more than 15 years (Al-Asmi, 2014). Desalination plants – the major drinking water suppliers in Oman (MRMWR, 2018) are vulnerable to serious threats, not only during emergency and conflict situations but also in other circumstances. Oil leakage, chemical and biological contamination, and red tides in the vicinity of the intakes of these plants become more frequent that may seriously affect the production of desalinated water in the country. Therefore, the development of strategic reserves in aquifers is not only desirable but a must to ensure that the domestic demands are met during emergency times and periods of other adverse circumstances (e.g. contamination in the vicinity of regular intake off-shore zones of desalination plants) (Missimer, 2014). Unlike groundwater, surface water can't be stored for an extended period of time and in sufficient quantities. On-surface storing even small volumes of freshwater is prohibitively expensive. From the economic point of view, aquifer systems represent a viable solution for water storage and recovery (Zekri et al., 2013; Arshad et al., 2014; Missimer, 2014; El-Rawy et al., 2019) This study aims to investigate the feasibility (and the know-how) of the implementation of the ASR system in the Duqm area, Oman, to satisfy the freshwater demand during emergency situations for a specific period of time and to support water supply during peak demand periods. To that end, a numerical model has been developed to study ASR in the Duqm area.

ABSTRACT. We propose a water bank where the river basin authority uses its monopolistic-monopsonistic position (i.e., there are no other buyers/sellers in the basin-the situation in most river basins worldwide where markets do not exist yet) to set monopoly-monopsony prices during the buyback (monopsony) and a subsequent lease phase (monopoly). This makes possible to buy water at low monopsonistic prices and sell a fraction of this water at high monopolistic prices, where the water reacquired in excess of sales is used to restore natural assets. The defining characteristic of the proposed water bank is that it uses first degree price discrimination. Under first degree price discrimination, the water bank pays/asks a different price for every unit of water sold/bought, which matches the maximum/minimum price that every buyer/seller in the market is willing to pay/accept (reserve price). Thus, both the consumer and producer surpluses are wholly transformed into public revenues, which reduces the budgetary burden of the environmental restoration without negatively impacting economic efficiency. In order to assess the potential of the proposed water bank we use a modular hydroeconomic model that integrates the hydrological Decision Support System (DSS) AQUATOOL and an ensemble of 4 mathematical programming models. The rationale for the use of an ensemble approach is that of sampling uncertainty in the estimation of the willingness to pay/accept of economic agents in the model, so to obtain a robust estimation of the reserve price and a reliable range for the economic performance of the proposed water bank. Methods are illustrated with an application to the Upper Douro in Spain, an otherwise water abundant basin increasingly affected by drought events. Results show that the water bank with price discrimination outperforms conventional water banks in terms of economic efficiency and yields a net positive public revenue, while ensuring hydrological integrity. Thus, we conclude it is possible to achieve win-win solutions for the environment and the economy at no cost for the public sector through the use of price discrimination in water banks.

ABSTRACT. Drought events occur more frequently under recent climate change. In general, meteorological drought is the precursor to soil moisture or hydrological drought. Thus, understanding the features of meteorological drought and its translation to soil moisture or hydrological drought is critical for early warning and proper management of regional water resources. There are various methods to examine and calculate drought characteristics and propagation time from meteorological to hydrological and soil moisture drought. Though, each method has its advantages and limitations and thus cannot define proper propagation attributes. In this study, drought propagation based on the time series framework was obtained to explore the propagation process from one drought state to another. Standardized Precipitation Index, Standardized Soil Moisture Index, and Standardized Streamflow Index were calculated at different time scales using, precipitation, satellite-based soil moisture, and streamflow for the period of 1979 to 2016. Results suggested that average drought propagation was 3.4 to 8.3 months (meteorological to hydrological) and 2.3 to 5 months (meteorological to soil moisture) in the selected catchment. The periodic characteristics using cross-wavelet analysis indicated that meteorological drought was mainly responsible for those of soil moisture and hydrological drought. Contrarily, correlation analysis exhibited that propagation time between meteorological to soil moisture was 1 to 2 months while meteorological to hydrological was 11 to 12 months. Overall, the findings of this study may help to minimize the drought hazards posed by meteorological droughts.

ABSTRACT. Rapid global changes are putting a devastating effect on water stress both in terms of quality as well as quantity. Despite the frequent use of IWRM (integrated Water Resource Management) tools for water management, the long-term effect is not so sustainable because of lack of ownership by the local stakeholders. Considering this gap, this study uses a perfect combination of IWRM tool and participatory approach to design robust land-use and climate change adaptation policies at a local scale. This methodology (called the “Participatory Watershed Land-use Management” (PWLM) approach) consist of four major steps: (a) Scenario analysis, (b) impact assessment, (c) developing adaptation and mitigation measures and its integration in local government policies, and (d) improvement of land use plan. As a test case, we conducted PWLM in the Santa Rosa Sub-watershed of the Philippines, a rapidly urbanizing area outside Metro Manila. The scenario analysis step involved a participatory land-use mapping activity (to understand future likely land-use changes), as well as GCM precipitation and temperature data downscaling (to understand the local climate scenarios). For impact assessment, the Water Evaluation and Planning (WEAP) tool was used to simulate future river water quality (BOD and E. coli) under a Business as Usual (BAU) scenario and several alternative future scenarios considering different drivers and pressures (to 2030). Water samples from the Santa Rosa River in 2015 showed that BOD values ranged from 13 to 52 mg/L; indicating that the river is already moderately to extremely polluted compared to desirable water quality (class B). In the future scenarios, we found that water quality will deteriorate further by 2030 under all scenarios. Population growth was found to have the highest impact on future water quality deterioration, while climate change had the lowest (although not negligible). After the impact assessment, different mitigation measures were suggested in a stakeholder consultation workshop, and of them (enhanced capacity of wastewater treatment plants (WWTPs), and increased sewerage connection rate) were adopted to generate a final scenario including countermeasures. The main benefit of the PWLM approach are its high level of stakeholder involvement (through co-generation of the research) and use of free (for developing countries) software and models, both of which contribute to an enhanced science-policy interface.

ABSTRACT. EXHIBITION: CONCEPT NOTE Context Over the past few years, NBI has developed a solid knowledge base, data and tools of analysis that enhance understanding of the Nile Basin’s water and related resources leading to sound decision making. During this event the NBI will show case a rich collection of its Knowledge/ Communication products that have been published as well as web tools that have been developed over the past 20 years. Objective of the Exhibition • To increase awareness about What NBI is and what NBI does • To create awareness about the new 5-year NBI Basin Wide program and NBI 10 year Strategy • To increase visibility for the works that have been published in the NBI Knowledge/Communication products • To disseminate Knowledge products prepared by the NBI • To Network with exhibiting organizations during the event to build partnership Mode of presentation/Exhibition • Display of Infographic posters on the following topics: (i) Nile Basin Hydrology, (ii) Strategic water resources analysis, (iii) NBI priorities: 2017 – 2027; (iv) Why wetlands matter; (v) NBI@20: Key Milestones of Nile Cooperation. • Show case NBI knowledge and communication products hard copies formats • interactive products like the NBI documentaries • Visibility products (Pull up banners and Tear drops) Proposed list of Exhibitors • Nile-Secretariat • ENTRO and Projects • NELSAP CU and projects • Global water Partnership Eastern Africa • Nile Basin Discourse • NBI Development partners (World Bank GIZ, EU, etc.) Highlights of the Exhibition: • Show case unique interactive tools developed by the three NBI centers EXHIBITION-VISIBILITY MATERIALS

NO Communication/Knowledge Products Quantity 1. • 2021 – State of River Basin Report 300 2. • Corporate Report 2020 FR/EN 100 3. • Infographic Posters 5 4. • Benefits of booklet 50 5. • Ground water fact sheet 200 6. • Ground water Stickers 100 7. • Water resources Atlas 100 8. • Wetlands flagship papers 100 9. • The Niles 100 10. ONLINE Videos on the Nile

4 11. • Launch of the wetlands atlas Dummy Exhibited 1 12. VISIBILITY MATERIALS 13. Pull up banners 2 14. Tear drops 15. NBI Table flags and poll flags 18

ABSTRACT. Global warming has a crucial effect on variations and distribution of precipitation extremes, which result in floods and droughts. The evaluation of these extremes and the usage of appropriate drought indices are very important for the management of water resources and agricultural development. To fulfill this objective, values of indices that reflect precipitation extremes and drought indices were calculated based on observed data that cover the period from 1961 to 2005. Moreover, output from Coupled Model Intercomparison Project Phase 5 (CMIP5) historical model simulations was also used to identify the discrepancies in the model simulations. The results showed that wet-day precipitation increased at a rate of 1.9 mm/year over the entire study area. During the period as a whole, the maximum 1-day precipitation and the number of very heavy precipitation days showed no trend, whereas the simple daily intensity index exhibited a non-significant decreasing trend. The number of consecutive wet days showed a negative trend, while the number of consecutive dry days showed a positive trend with a slope of 0.33 days/year. Moreover, very small differences were found between the results of the multi-model ensemble mean of CMIP5 simulations and the values of the extreme precipitation indices assessed from the in situ stations. The modified drought indices under pan evaporation enhance the performance of drought indices in monitoring drought events in the study area. A comparison of the indices showed that the performance of the original composite index (CI) and CI based on pan evaporation is better than that of the Reconnaissance Drought Index (RDI) and RDI (Pan evaporation) at all of the stations.

ABSTRACT. The Ogallala is the largest aquifer in the US, which is supporting millions of acres of irrigated agriculture in eight states in the Great Plains. Agriculture in the region facing multiple challenges including low water use efficiency, extreme wind and water erosion, increasing climate extremes, decreasing soil health, declining biodiversity. Rainfall in the region is low and distribution is unpredictable. Strong winds aggravate frequent drought and heat stress in the region. The situation is expected to deteriorate in the future climate with predicted higher temperatures. Ogallala Aquifer, once considered never ending underground lake, is declining rapidly due to over exploitation leaving many wells dry. Traditional crops and cropping systems are not able to sustain highly productive irrigated agriculture and the dependent large animal industry. Therefore, we are assessing diverse approaches to improve sustainability of irrigated agriculture in the region. 1). Crop Diversification: Well-adopted, stress tolerant alternative crops, which can be grown with less irrigation compared to existing corn, sorghum and wheat are needed for the region. Our interest is to understand root systems, water use patterns, resiliency, and yield formation under increasing uncertainty in growing environment. Most of these alternative crops tried are needed by local industries in the region. 2). Deficit irrigation strategies: We need irrigation management strategies those reduce total water used by alternative crops and/or reduce competition for limited water with main commercial crops of the region. This will help in increasing area under alternative crops. Results from a number of trials suggest that crops varied in their sensitive growth stages and some of the desert crops tolerate significant stress after flowering. In general, preseason or dormant irrigation was beneficial in many deep rooted alternative crops. 3. Alternative Cropping Systems: Circular Buffer Strips is a novel concept where dryland portion of a center pivot irrigation system is rearranged using aerodynamic principles into circles of buffer strips of native cool and warm season perennial grass mixtures alternating with crop strips to enhance multiple ecosystem services. Promising results are seen in conserving heavy intensity rainfall, reduce crop stress, improve corn/maize crop productivity and water use efficiency. At the same time, the system improves biodiversity, carbon sequestration and reduces greenhouse gas emission and soil erosion. Intercropping protein rich legumes in between widely spaced energy rich forage sorghum can improve forage quality of the mixture and forage production per unit of water. If multiple strategies and multidisciplinary teams are used to address water issue more effectively, we can sustain Ogallala aquifer longer. The results from multiple research projects will be summarized in the presentation.

ABSTRACT. Sabkha Matti is a wide, north-south trending, salt-covered depression that extends 150 km south from the western Abu Dhabi coastline and across the border between the United Arab Emirates and Saudi Arabia. Sabkha’s evolution has been under the debate in the scientific community, with different conceptual models and hypotheses related to the source of brines. The hypothesis of ascending brine model states that the brine’s source is an upward leakage from the underlying formation. Hydrological, chemical, and isotopic analyses supported this assumption. Sabkha Matti is the largest sabkha in the world, but has not been adequately investigated as compared to the Abu Dhabi coastal Sabkha. The Sabkha’s limited environment and unstable soil strength characters do not allow to drive on the wet Sabkha surface. The Global Land Data Assimilation System (GLDAS) is a spatiotemporal simulation of global land surface states and fluxes created by coupling in situ and satellite data. We aim to estimate the Sabkha Matti’s water budget to validate the capability of GLDAS and other soil moisture products to evaluate whether we can quantify upward fluxes. GLDAS has a grid resolution of 0.25° × 0.25° and it is expected to provide local soil moisture estimation with a penetration depth up to 2 meters. Rainfall data were obtained from the European Centre for Medium-Range Weather Forecasts (ECMWF). An excess of evaporation over precipitation and shallow water tables (0.2–1.8 m) are the main causes of Sabkha Matti’s development. Previous studies have suggested that the inflow components in the water budget to Sabkha Matti include: 1) direct precipitation; 2) shallow groundwater entering laterally from the surrounding mainland; and 3) upward leakage from underlying regional aquifers. However, the current study hypothesized that redefining the soil moisture time series data from the GLDAS may lead to a better representation of shallow groundwater storage changes for Sabkha Matti. The soil moisture magnitudes retrieved from the GLDAS were higher in Sabkha Matti than those in the surroundings. This contradicts the fact that rainfall rates are lowest in sabkha areas. The estimation of the water budget in Sabkha Matti clearly shows that there is another flux contributing to the water budget. Using the data obtained from remote sensing, the calculated upward flux for the period 2003–2018 varied from 0.5 to 6 mm/year. Based on the previous research that is based on field data, isotopes, and geochemical analyses, the source of solutes in Sabkha Matta is derived from an upward flux with an estimation of 1–4 mm/year. The similarities in findings helped to validate remote sensing data and supported the ascending brine model hypothesis. In summary, the GLDAS’s capability to estimate shallow groundwater resources was first validated at Sabkha Matti. Sabkha Matti’s hydrologic budget is known and simple to quantify; thus, we suggest to consider this area for future soil moisture satellite data calibration and validation. Overall, the GLDAS products have enhanced the understanding of Sabkha Matti hydrologic dynamics and the hypothetical water budget supported with the ascending brine model.

ABSTRACT. Generalized Likelihood Uncertainty estimation (GLUE) technique is utilized for the parameter identification, calibration and uncertainty analysis of a conceptual NAM (Nedbor Afstromnings Model) rainfall-runoff model. Hydro-meteorological data of a mountainous catchment was used for the current study and initial one year data was consumed as a burn in period and was not counted towards the estimation of uncertainty bounds. The model efficiency was checked using Nash Sutcliffe Efficiency (NSE), Root Mean Square Error (RMSE), Relative Volume Error (RVE) and Volumetric Efficiency (VE) metrics while the uncertainty was analyzed using 95% prediction uncertainty (95PPU), P-factor and R-factor. NSE values were obtained as 0.75 and 0.76 for the calibration and validation period respectively. While the RMSE values were 0.78 and 0.80. Similarly, validation period was able to capture more observations (70%) as compared to the calibration period (67%). Nash Sutcliffe Efficiency was used as a likelihood measure in GLUE procedure with a threshold value of 0.7 on the basis of the cumulative distribution graph of the simulated discharges and 10000 simulation were performed accordingly. It was found that only 255 parameter sets could cross the defined threshold value, which were nominated as behavioral parameter sets and retained for further simulations. Overall, hydrological modelling efficiency and GLUE results were in good agreement.

ABSTRACT. Regardless of disagreements on how influential the reasons are natural or anthropogenic, a vast majority of scientists agrees that the climate change is occurring and yet the phenomenon is observed to be accelerating faster than was originally expected. Interventions are being applied to deal with climate change on two fronts, climate change mitigation and climate change adaptation. The former can be regarded as a preventive/proactive approach while the latter, a reactive measure. However, there is not much evidence of ‘double-barrel’ interventions (both in theory and practice) in which both, the mitigation and adaptation, are addressed together, while there is a plethora of literature on the two being tackled individually and discretely. In this specific context, more realization, additional awareness and enhanced knowledge and efforts are required in connection to the water-environment and SUDS (Sustainable Urban Drainage Systems) applications, which is the focus of this study. SUDS can simply be described as an anthropogenic water-environment mimicking the natural water-environment as far as appropriately possible, while being socially acceptable (e.g. amenities and esthetics), environmentally friendly (both protecting and enhancing); and economically viable (cost effective). This study investigates the potential of how far SUDS can be deployed in the aforesaid dual/double-barrel interventional context. So that, climate change can simultaneously be mitigated and adapted more effectively via the same management measure in a given anthropogenic hydro-environment. The mitigation can involve decarbonization of water and the adaptation regards catering for climate change impacts that have already occurred and are further to happen due to the momentum climate change has already gained. This ‘two-in-one’ intervention approach is being referred to as killing two birds – mitigation and adaptation – with one stone, that is, SUDS. Based on the reviewed literature, the study also employs illustrative examples as well as real-world case-studies to delineate the ‘double-intervention’ concept with innovative insights.

ABSTRACT. Considering that urbanization has become quite widespread across the globe, studies are carried out in the water resources domain in order to prevent the negative effects of urban flash floods are of utmost importance. One of the various tools used for the conventional flood mitigation strategies is the storm water grate inlets. In this context, it is essential to note that the physical properties, i.e., the location and shape of storm water grate inlets as well as the transversal and longitudinal slope of the road can be expressed as some of the significant variables for the identification of hydraulic efficiency. The hydraulic efficiency of storm water grate inlets is described as the ratio of the flow captured by the inlet and the total flow approached to the inlet. Thus, identifying the intercepted discharge is crucial for the optimum grate inlet selection. In this study, the efficiency of six of the storm water grate inlets used throughout Istanbul was investigated with an experimental setup set up established in the Hydraulics Laboratory of Istanbul Technical University. In addition, two tree-based ensemble machine learning algorithms, random forest and adaptive boosting, one for bagging and one for boosting, respectively, were employed to model the measured variables. Also, two meta-heuristics, i.e., genetic algorithm and particle swarm optimization, were incorporated into both algorithms to tune their hyper-parameters. According to the results obtained, RF outperformed the Adaboost for each of hyper-parameter optimization strategy, while the PSO yielded superior performance compared to the GA. Overall, best performed model was obtained through the hybrid PSO-RF model with NSE and R² values of 0.8896 and 0.8990, respectively. Even with a slight difference, the lowest performance was attained through the GA-Adaboost model with NSE and R² values of 0.8699 and 0.8815, respectively. The comparative evaluation was carried out within the four different combinations of soft computing applications showed that the researchers can use four of those methods to simulate the intercepted discharge by storm water grate inlets, while the PSO-RF is more functional among each other.

ABSTRACT. Agriculture is one of the biggest water demanding and consuming sector globally. India is having excess of natural water resources. Though, due to several geographical restraints and the current practices of utilization, the water sources for irrigation purposes became finite. Additionally, the exploitation of water leads to water logging and salt problems when accounted with the application for agriculture. In India the irrigated land encompasses around 36% of the total sown area. Currently the agriculture sector attributes around 83% of all water usage. Globally the demand for water is surging from all water user sectors. Most of the irrigated water is supplied by groundwater wells. However, decline in groundwater levels in many irrigated areas increase concern over the long-term availability of water. In other areas where recharging aquifer or alluvial aquifer exists, irrigation may not lead to long term reduction. Although irrigational uses of water as well as increasing demand from other sectors can cause substantial shortfall with major ecological as well as economic impacts. In both situations, irrigation managers require to frame precise uses of water within the limits of the irrigation allocation which no more is applied than required for the crops. The developed IWAT 1.0 model will be useful for calculating crop water requirement and irrigation schedules. The recommendations of the model can help in improvement of crop production and proper management of water resource.

ABSTRACT. Due to population growth and rapid industrialization, massive withdrawals of groundwater resources have resulted in seawater intrusion(SWI) into coastal aquifers worldwide. This problem is common in arid and semi-arid regions (40% of the world's population.) The effects of seawater intrusion on the local community's health and economic and socio-cultural developments in coastal areas have prompted a wide range of research. The current study's goal is to provide a comprehensive review of the processes that control seawater intrusion into coastal aquifers over the last 50 years and the necessary mitigation measures. The SWI-associated literature is available from the Scopus bibliographic database and statistical and scientific mapping analysis by using Bioblioshiny to excavate existing research achievements further. This intends to examine the reputation and trends of seawater intrusion in coastal aquifer research from 1970 to 2021 to assist other researchers in comprehending the global scope of study and predicting the dynamic directions of seawater intrusion in coastal aquifer research. Implementing SWI knowledge, such as processes, investigative methodologies, and managerial approaches is perhaps the most critical scientific problem in SWI research. Strategies are required to close the gaps between SWI knowledge and management practice. To illustrate the benefits of SWI research methodologies and knowledge, more studies that retrospectively and critically analyze the effectiveness of management practices, particularly initiatives deriving from SWI research findings, are needed to illustrate the benefits of SWI research methodologies and knowledge. The following are the goal: a) Examine the patterns of seawater intrusion in journal publications about coastal aquifers, and b) Comprehensive review of the processes that control seawater intrusion into coastal aquifers and the new proposed methodology are then explained in detail.

ABSTRACT. The quality of observations is fundamental issue in natural sciences. Here, the accurate and complete data is required to accomplish satisfactory estimations. There are several factors impairing the quality of measurements, such as a broken or mis-calibrated device and error in reading the measurements. Thus, this study primarily aims the imputation of the missing values in measurement of solar radiation data. Deep Neural Network (DNN) method was used to handle the missing data, and benchmarked with the classical approaches, i.e., Mean Imputation (MI), which one of the most frequently adopted data imputation method in the pertinent literature, the Linear Interpolation (LI) and Spline Interpolation (SI). The overall results highlighted that the DNN method outperformed its counterparts in terms of missing value handling through providing a greater accuracy according to the various performance metrics compared to the classical methods. It is believed that the proposed approach could make valuable contribution to the body of knowledge as well as providing significant overview to the interested researchers by filling the important gap exists in the pertinent literature.

ABSTRACT. Groundwater is the vital source of freshwater during droughts, yet groundwater is scarce in many areas owing to overexploitation or salinity. According to the International Groundwater Resource Assessment Centre (IGRAC) inventory, the total area with high groundwater salinity at shallow and intermediate depths is 24 million square km. The basins of West and Central Asia have the largest area with high groundwater salinity. Aquifer Storage and Recovery (ASR) can be useful in saline regions to ensure freshwater availability during droughts. In the ASR method, artificial injection of surplus freshwater available on the surface during the rainy season is done for future recovery during draughts. In the saline aquifer, injected freshwater stores near the ASR well by replacing the ambient saline water due to density difference. The performance of the ASR system in saline regions is evaluated by recovery efficiency (RE). The RE is the ratio of total injected freshwater to the amount of water recovered. The total amount of injected freshwater can be recovered due to the losses from mixing phenomena and the buoyancy stratification process of the stored freshwater. The mixing losses can be controlled by selecting sites with appropriate hydrogeological parameters. But there is still a requirement to understand the influence of hydrogeology on ASR performance. This study aims to delineate the influence of aquifer properties such as aquifer hydraulic conductivity, effective porosity, hydraulic gradient, longitudinal dispersivity, transverse dispersivity, and groundwater salinity on ASR performance. In this study, we have used a variable-density groundwater flow model using MODFLOW and SEAWAT for the simulations. Results show that low hydraulic conductivity and hydraulic gradient in thin aquifers with low longitudinal dispersivity favor ASR performance in salt-affected regions. Recovery efficiency is unaffected by transverse dispersivity and aquifer porosity, while hydraulic conductivity and dispersion coefficient is affected by aquifer porosity. The outcomes of this study will have a significant impact on the site selection procedure for the ASR scheme and its overall performance.

ABSTRACT. Concentrated solar thermal energy serves as a least expensive and eco-friendly methodology for use in the heating of brine water during multi-stage flash distillation process instead of generating steam developed by industrial methodologies. In this work, a solar receiver based on a microchannel heat exchanger has been conceptualized; parametric study performed on the microchannel heat exchanger is also detailed. The mathematical model is solved with the help of continuity, Navier-stokes and energy equations. Fluent module of ANSYS Workbench is used for computing the model with studies done for the Reynolds number range of 50 to 1500. With water being used as the working fluid and aluminum alloy as the substrate material, the thermo-hydraulic performance of the microchannel heat exchanger is evaluated using two characteristic parameters such as thermal resistance and pumping power. The results showed that the increase in Reynolds number decreases and increases the thermal resistance and pumping power respectively. The increase in the hydraulic diameter of the circular microchannel heat exchanger led to the reduction of both thermal resistance and pumping power. The influence of the reduction in the length of the microchannel was highlighted in terms of reduced thermal resistance as well as pumping power.

ABSTRACT. Estimating the recharge rate of an aquifer is an uncertain and imprecise operation, which depend on a multitude of factors, as has been explained in various technical-scientific documents for many years. Proof of this are the different results that different calculation methodologies usually provide when applied to the same aquifer. In this regard, it is clear that those estimates that can be subjected to calibration by contrast with the actual data taken and measured in the field or laboratory will always offer greater confidence and certainty. This is the case of the new version of the RENATA code used in this paper.

Since the user manual of this new version has not yet been published, a concise but at the same time solid explanation of its hydrogeological and computer foundations is made within the methodological section. The code applies to four bodies of groundwater that have different hydrogeological characteristics. Three of them are overexploited, while the fourth has increased its resources thanks to the excess irrigation that is carried out with surface water from a transfer.

Spanish legislation considers that recharging an aquifer is assimilable to a renewable resource. The latter are determined in this article for both the undisturbed state (without pumping) and for disturbed one (with pumping and irrigation returns). Since the RENATA code allows distribute the recharge according to watershed and groundwater divides, an analysis is made of the way in which it is distributed according to the geographical position they occupy. This aspect is very important in the case of the goundwaterl divide since its location varies over time.

ABSTRACT. The River Nile basin is a transboundary basin shared by 11 countries in Africa and include three major rivers: the Blue Nile, the White Nile, and the Atbara River. The construction of the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile to supply hydropower to Ethiopia has become a concern for downstream countries (Sudan and Egypt) in terms of water share reduction. To assess the impact of the GERD on downstream countries, sufficient data must be obtained on the upstream dam storage plan (from Ethiopia). As an alternative, remote sensing can be utilized to collect quantitative information about the water storage upstream of the dam; however, satellite data must be validated before it can be deemed credible. The Gravity Recovery and Climate Experiment (GRACE) satellites provided continuous monthly data for terrestrial water storage worldwide. Thus, this study aimed to integrate data from multiple satellites, such as the GRACE, GRACE Follow-On (GRACE-FO), The Global Precipitation Measurement Mission (GPM), European Center for Medium-Range Weather Forecasts (ECMWF) Reanalysis 5th Generation (ERA5), Sentinel-1, and SRTM, in addition to in-situ data to validate the GRACE data and consequently develop an approach to quantify the volume of water stored in the GERD lake after the filling process. Analysis of the 2003–2014 GRACE data highlights a trend of peak and low magnitude in September and June 2021, respectively. Meanwhile, cross-correlation analysis of in-situ measurement data from the Eldiem River gauge (located in Sudan close to the Ethiopian border) with GRACE data shows a value of 0.61 at lag = 0 and 0.76 at lag = 1. Data acquired by GRACE-FO, which was launched in 2019, showed a significant water mass increase in September 2020. Compared to previous years, the increase in equivalent water height derived from GRACE FO was about 200 mm, whereas the VH polarized Synthetic Aperture Radar (SAR) data obtained from Sentinel-1 detected that the water body increased by 320 km2 during the 2020 and 2021 impoundment. Rainfall data were obtained from GPM and ERA5 to assess whether rainfall contributed to the increase in terrestrial water storage. The annual rainfall data clearly show that rainfall during 2020 and 2021 was not at 20-year highs. Thus, the increase in terrestrial water storage volume in 2020–2021 can be evidentially attributed to dam filling, which started in the summer of 2020. Overall, the GRACE was able to capture the water mass change when the filling began, however, it underestimated the water storage volume. Alternatively, by coupling the Sentinel-1 SAR data with the SRTM DEM, we were able to estimate the water storage volume during the filling of the GERD reservoir. The estimated water volume resulting from the impoundment from June 2020 to September 2021 was calculated to be about 10 billion m3. This study revealed the importance of incorporating satellite data into the monitoring of reservoir filling in the dam lakes, especially in locations where ground data are missing such as in the GERD dam lake in Ethiopia.

ABSTRACT. Rice consumes more water than any other crop, potentially leading to unsustainable water withdrawals in command areas of irrigated rice ecosystem. Rice production in irrigated ecosystem is going through transition due to rising scarcity of land, water and labour. A major adjustment can be expected in the tillage and method of crop establishment. Direct seeding rice (DSR and WSR) has been proposed as one means of achieving these objectives. Therefore a field study was conducted for three seasons on a clay loam soil in Karnataka, India, during Kharif Season (2015 and 2016), Rabi season (2015) to investigate the tillage and crop establishment impacts on land and irrigation water productivity in Tunghabhadra rice command area of Southern India. The experiment was conducted in Split-split plot design comprising two tillage practices in main plots, two establishment methods in sub plots and three irrigation scheduling practices in sub-sub plots. Tillage treatments were Dry (No puddling) and wet tillage (puddling), Establishment methods were Direct seeding (Dry Seeded Rice-DSR, Wet Seeded Rice-WSR) and Transplanting (Non Puddle Transplanted Rice-NPTR, Puddle Transplanted Rice-PTR), Irrigation treatments were based on soil water tension (SWT) ranging from continuous flooding/saturation (daily irrigation) to alternate wetting and drying (AWD) with irrigation thresholds of 10 and 40 kPa at 18-20cm soil depth. Rainfall was average and well distributed in 2014 (763.80 mm), and less than average and well distributed in 2015 (384.60). Pooled three seasons results indicated that with methods of establishment practices, direct seeding crop matures earlier in 115 days in comparison with transplanted delayed crop maturity by 13 d. direct seeding was more affected than transplanting and more so in the drier year. Crop performance in terms of tiller density, leaf area index and growth rate and yield components were also similar in both establishment methods when irrigation was scheduled daily or at 10 kPa, but crop growth and yield parameters were significantly lower at 40 kPa in both direct seeding and transplanting establishment methods. In each individual season, yield of direct seeding and transplanting were similar when irrigation was scheduled daily or at 10 kPa. Yields of both direct seeding and transplanting declined under higher water deficit stress (40 kPa irrigation threshold), but more so in direct seeding, and more so in drier year. There was a very large and significant decline in irrigation water input with irrigation at 10 kPa compared to daily irrigation in both establishment methods, but only a very small decline in irrigation amount when the threshold was increased from 10 to 40 kPa. Irrigation water use in direct seeding treatments was significantly lower than in respective transplanting treatments (32% water saving in direct seeding compared to transplanting). The results suggest the feasibility of reducing irrigation amount while maintaining yield by replacing transplanting with DSR with AWD during wet season and WSR with AWD during dry season, provided that soil tension is kept lower than 10 kPa at 20cm depth, but that threshold needs to be tested over wider range of site conditions and varieties.

ABSTRACT. ABSTRACT Aba as an industrial and commercial area generates large amount of waste and indiscriminate disposal of waste in Enyimba and its environs has brought about severe environmental issues. Physiochemical and microbiological analysis were carried out for water samples from four boreholes (BH 1, BH 2, BH 3, and BH 4 with distance of 80m, 251m, 348m and 455m respectively, and an elevation of 59m, 58m, 60m, and 56m respectively) and a leachate sample from the dumpsite to determine the effect of leachate (dumpsite) on the groundwater quality. The total parameters analyzed were twenty one (21), namely; Temperature, pH, Conductivity, TDS, Colour, DO, alkalinity, Nitrate, Nitrate-Nitrogen, Copper, Iron, Chlorine, Chromium, Arsenic, Lead, Zinc, BOD, COD, total bacterial count, total coliform count and E.coli. The temperature of borehole water and leachate ranged from 26.70 C to 29.70 C, and the pH ranged from 5.2 to 6.3 in borehole water indicating toxic pollution, but neutral (pH – 7.1) in leachate sample. Colour (Platinium Cobalt Unit) ranged from 13PCU to 13850PCU in borehole water and leachate. The concentrations of Zinc, Lead, Chromium, Copper, Nitrate, Chlorine and Iron ranged from0.09mg/l in BH3 to 0.25 in BH 4, Lead 0.001 in BH 3 to 0.125 in BH 1, Chromium 0.014 in BH 3 to 0.037 in BH 2, Copper 0.00 in BH 3 to 0.08 in BH 4, Nitrate 234.2 in BH 4 to 343.0 in BH 1, Chlorine 0.35 in BH 3 to 1.71 in BH 4, and Iron 0.19 in BH 3 to 0.42 in BH 4 respectively. In the Bacteriological analysis, Total Bacteria Count, Total Coliform Count and E. coli were analyzed with mean value of 62.00, 23.73 and 6.50 respectively. The variation in concentration of microbiological parameters was in respect to distance from the dumpsite and elevation of the sampling point. There is therefore a need for adequate planning, design, construction and location of dumpsites to ameliorate groundwater, surface water and soil pollution in residential areas.

ABSTRACT. Innovation is getting more importance in modern agriculture than ever before. The agricultural industry, as a whole, is facing huge challenges from rising costs of inputs, shortage of labour and changes in consumer preferences and sustainability. Water becomes a scarce resource due to increased demand for industrial, agricultural and domestic purposes. Hence, the modernization of water management methods is necessary to achieve better productivity. So, adoption of alternative agro techniques will help in effective and efficient utilization of these inputs. Employing of micro irrigation techniques is the most effective way to manage these resources, efficiently. Adoption of micro irrigation might help in bringing additional area under irrigation, increasing the productivity of crops and water use efficiency. Management of water and nutrient are the prime factors attributes for yield improvement in corn. A field experiment was carried out during kharif 2019-20 and 2020-21 at agroforestry field unit, UAS, GKVK, Bengaluru, which consisted of twelve treatments replicated three times, assigning three levels of irrigation as main plot with four sub plots of nutrient management practices was laid out in a split plot design. The results revealed that sensor based drip irrigation at 50 per cent depletion of available soil moisture (DASM) along with nutrient expert software based nutrient management approach recorded significantly higher leaf area at harvest (9020 cm2 plant-1), higher kernel yield (9725 kg ha-1) irrigation water use efficiency (23.45 kg ha-mm-1) and total water use efficiency (13.23 kg ha-mm-1) on pooled basis. The treatment receiving surface irrigation along with recommended dose of fertilizers recorded significantly lower leaf area (5817 cm2 plant-1), lower kernel (6916 kg ha-1) irrigation water use efficiency (11.27 kg ha-mm-1) and total water use efficiency (7.38 kg ha-mm-1). The nutrient management using nutrient expert saved 26.6 and 20.0 per cent nutrients as compared to recommended dose of fertilizer. Whereas, sensor based drip irrigation saved 32.6 and 32.2 per cent of irrigation water as compared to surface irrigation during first and second year, respectively. The availability of information on proximal sensors i.e. sources and level of nutrients and water at individual farmer level can provide 4R compliance (i.e. Right source, Right amount, Right time and Right place) which aids in improvement of crop productivity by maximal utilization applied resources viz., nutrient and water.

ABSTRACT. Water harvesting structures are extremely important to conserve precious natural resource like soil and water which is deteriorating due to the uncontrolled flood flushes that caused damages, in time where it could be very useful if suitable technical methods were applied to keep it. Check dams are one of these structures that could be very useful if certain conditions were available in the flood area. In this study Ali Al Gharbi which is located in the southeast part of Iraq near to the Iraqi- Iranian borders, is chosen as an area that suffered from frequently flood flushes that come from the Iranian land. Those floods damaged all the infrastructures like bridges, roads and also the farms and villages in its way. Remote sensing and GIS technologies were the appropriate tools to choose the suitable sites for check dams in the area. The various thematic maps such as Land use, Drainage, HSG, Slope and DEM maps were prepared for selecting suitable sites for construction of check dams. Four check dams and four percolation tanks were proposed for the construction that may serve the purpose of soil and water conservation to help in sustainable development of the catchment area. The proposed check dams can be very useful to supply water for irrigation in dry seasons.

ABSTRACT. Actual flood mapping and quantification in an area provide valuable information for the stakeholder to prevent future losses. This study presents the actual flash flood quantification in Al-Lith Watershed, Saudi Arabia. The study is divided into two steps: first is actual flood mapping using remote sensing data, and the second is the flood volume calculation. Two Sentinel-1 images are processed to map the actual flood, ie, images from 25 May 2018 (dry condition), and 24 November 2018 (peak flood condition). SNAP software is used for the flood mapping step. During SNAP processing, selecting the backscatter data representing the actual flood in an arid region is challenging. The dB range value from 7.23–14.22 is believed to represent the flood. In GIS software, the flood map result is converted into a polygon to define the flood boundary. The flood boundary that is overlaid with Digital Elevation Map (DEM) is filled with the same elevation value. The Focal Statistics neighborhood method with three iterations is used to generate the flood surface elevation inside the flood boundary. The raster contains depth information is derived by subtraction of the flood surface elevation with DEM. Several steps are carried out to minimize the overcalculation outside the flood boundary. The flood volume can be derived by the multiplication of flood depth points with each cell size area. The flash flood volume in Al-Lith Watershed on 24 November 2018 is 155,507,439 m 3. Validity checks are performed by comparing it with other studies, and the result shows that the number is reliable.

ABSTRACT. In the field of soil hydrology, the Richards equation is commonly used to model water flow in unsaturated soils and to determine the main components of the hydrologic cycle, as rainfall partitioning into surface runoff and infiltration. The high nonlinearity of the Richards equation makes it very challenging to obtain an analytical solution, especially for situations that are meaningful in applied hydrology. Recently, for constant rainfall intensity, under the simplified hypothesis of gravity-driven infiltration, and by assuming a capacitance framework so that the water redistribution dynamic within the unsaturated zone is instantaneous, a simplified solution of the Richards equation that considers the Brooks and Corey hydraulic conductivity function was suggested. By maintaining the assumption that the infiltration process is dominated by gravity, the objective of this paper is to relax the capacitance sketch applied to only one reservoir, by replicating the internal water content travel times through the discretization of the soil profile into multiple tanks connected in series. First, the previous analysis is briefly summarized, which is useful for the further development. Then, for a fixed soil pore connectivity index (c = 0.5), which could be assumed for sandy soils, the same approach is extended to multiple non-linear reservoirs to model water balance components, achieving more reliable conditions. The approach followed in this study is a simple hydraulic approach, thus, it could be not affected by uncertainty, provided the hypotheses of the gravity-driven infiltration and c = 0.5 are satisfied. A comparison with the numerically derived solution of the Richards equation (via Hydrus-1D), where the gravity-driven assumption is relaxed, is discussed, the effect of the number of reservoirs is analyzed, and applications for both constant and time-variable rainfall intensity are performed.

ABSTRACT. As the Earth's atmosphere contains an abundant amount of water as vapors, a material which can capture a fraction of this water could be a cost-effective and practical way of solving the water scarcity. Recent advances have focused on combining both hydrophilic and hydrophobic properties to capture atmospheric water. There are many materials such as polymers that can help in water harvesting. Here we present a large scale, facile and cost-effective method to fabricate water-harvesting surfaces consisting of nanostructured array of copper oxide nanowires on a copper foam matrix. Furthermore, this array was decorated by a toping of poly vinyl alcohol (PVA). The fabricated architecture synchronizes the hydrophilic/hydrophobic surface property resulting in high wettability and excellent fog harvesting capability. The physicochemical property of the designed nano-architecture was elucidated by SEM, EDS, FTIR, Raman and contact angel measurements. The performance was correlated with the structure property relationship. The fabricated architecture is considered an avenue for designing efficient fog harvesting devices.

ABSTRACT. Aim To develop a rainfall-runoff model within HEC-HMS for the lower Clutha catchment downstream of Roxburgh to provide flood forecasting/warning for Balclutha township.

Method To aid the rainfall-runoff modelling process of the lower Clutha catchment, significantly 24 independent high flow events of the lower Clutha have been identified and studied. Runoff volumes from each sub-catchment which has a flow site at its outlet have been estimated for all selected events, along with the corresponding total precipitated rainfalls for each telemetry rainfall site in or close to this area. A rainfall-runoff analysis of available telemetry rainfall and flow sites in this lower Clutha catchment, similar to the analysis proposed by Mohssen [8], have been carried out, using multiple regression, to identify rainfall sites which best represent rainfall over each sub-catchment which has a flow recorder at its outlet, and to estimate effective rainfall and the weights for these rainfall sites. HEC-HMS model’s parameters were estimated based on the rainfall-runoff analysis, analysis of available gauging at flow sites in the catchment, analysis of historical events, topographical information and analysis of the recession part of flow hydrographs. Further optimization of these parameters was achieved.

Results The model consists of 16 sub-catchments between Roxburgh and Balclutha, one source of flows which is Roxburgh dam, 16 river reaches, 13 junctions and one sink for the river outlet at Balclutha. To be consistent when estimating the runoff for each event, the time for recession after the peak flow has to be the same, and 300 hours have been selected as long enough to guarantee the inclusion of all runoff. However, many events will have disruption of this recession by rainfall before the 300 hours target, and in this case an extension of the recession has been modelled and applied to these events with “short” recession

Rainfall variability over the lower Clutha sub-catchments “total area of about 5000 km2” is quite high. Results show that while “available” rainfall can represent the Waipahi flows reasonably well, it fails to properly simulate the Waitahuna flows. The same applies to several sub-catchments of the Lower Clutha, and this, in turn, will be reflected in the capability of any developed rainfall-runoff model to produce reliable flows based on available rainfall sites.

The model was used to forecast the flows of the February 2020 flood event and it was capable of suitably giving a warning of flows exceeding the warning level about 36 hours before the event.

Conclusions A flood forecast model has been developed for the lower Clutha catchment, which was capable of properly predicting the Balclutha flood event of February 2020. A new approach has been developed to aid the estimation of the weights for the rainfall sites to produce more reliable areal rainfall for the sub-catchments. In addition, this developed new approach of rainfall-runoff analysis highlights the ability of the available rainfall sites to properly simulate the areal rainfall over the sub-catchments.

ABSTRACT. Australia has been experiencing floods and droughts more frequently like many other countries. Climate change and anthropogenic activities are assumed to be the main driver of these changes in floods. As annual maximum flood (AMF) data are widely used in flood risk assessment, it is of utmost significance to investigate the trends in AMF data to understand long term changes in flood data. This study investigates trends in AMF data within the state of New South Wales (NSW) in Australia. Initially, 176 stream gauging stations with minimum AMF record lengths of 20 years are selected for this study. The quality of data is assessed visually and statistically. Finally, 36 stream gauging stations with AMF record lengths ranging from 50 (1971-2020) to 91 (1930-2020) years are selected to examine trends in these AMF data. It is expected that a higher record length captures multiple and long-term climate variability cycles whereas a shorter period may provide misleading trends in AMF data. The selected stations cover mountainous, flood plains and coastal regions of NSW with catchment areas in the range of 15 to 894 km2. In this study, non-parametric Mann-Kendall (MK) tests are used to detect trends. The MK tests are applied at 5% and 10% significance levels. The result shows statistically significant trends in nine stations with 5% significance level, and in 14 stations with 10% significance level. It is seen from the analysis that 39% of the stations have statistically significant trends (at 10% significance level) in the AMF data. The AMF series of each station is divided into two equal periods of record and then the mean and standard deviation values of each sub-series are calculated. It is found that the mean and standard deviation significantly decrease with time for most of the selected stations. For all the 14 stations showing statistically significant trends, the average annual peak flow is found to decrease from 4% to a maximum of 64% (with an average decrease of 39% over all the 14 stations). The study also shows that out of the 36 stations, a general downward trend in the AMF data exists in 32 stations (when significance level is disregarded). Based on these results, it is evident that there exist decreasing trends in AMF data for most of the stations in NSW. This result highlights the importance of applying non-stationary FFA in NSW.

ABSTRACT. Groundwater resources are considered of utmost importance in arid regions due to scarcity and non-availability of surface water sources. Applications of geo-modeling with machine learning and artificial intelligence algorithms are rapidly advancing for the sustainable management and conservation of those resources. In this pilot study, we explore the state-of-the-art ANN technologies as an innovative technique in a geo-modelling framework for the prediction of changes in groundwater level of a part of Al Ain city, United Arab Emirates (UAE). The ANN models produce predicted variability in groundwater comparable to the observations and thereby strengthen the future use of the system in machine learning. Results and observation data highlight moderate variability in groundwater level which can be related to both natural and anthropogenic factors. Extensive abstraction, changes in precipitation rates, population growth and urbanization strongly contributed to and controlled the groundwater fluctuations and level variability throughout the region.

ABSTRACT. Groundwater resources are one of the most valuable assets for many regions around the world and uncontrolled practices for these resources are required to avoid future complications. One of these practices is the overexploitation, or high abstraction, of the groundwater. In arid climates, such as in the United Arab Emirates (UAE), where low average annual precipitation and high annual evapotranspiration the overexploitation of the groundwater could result in groundwater deficit due to the low annual recharge. The fast development of the UAE required a huge amount of water, especially for domestic and agricultural sectors. Groundwater overexploitation can result in serious environmental issues such as land surface deformations. This study provides an overview of land surface deformations over selected agricultural areas in the Al Ain region, Abu Dhabi Emirate, using satellite-based Synthetic Aperture Radar Interferometry (InSAR) techniques to assess the current situation of the land stability in those areas. The InSAR techniques measure land surface movements in millimetric scale with high spatial resolution depending on the operating frequency. This study aims to identify the affected areas with land surface deformations due to groundwater overexploitation in order to enhance the groundwater practices to avoid further damages.

ABSTRACT. A field technique to deduce Ksat in shallow groundwater conditions is bailout test in which one records and interprets the recovery of water level in an excavation or pit. This technique was used in 9 pits at Sultan Qaboos University (SQU) campus in Oman to calculate Ksat. If the perched aquifer, tapped by the pit, is assumed to be effectively homogeneous, then Ksat is quickly determined by observing the filling (in hours) of an excavated pit, when water from the pit is quickly (in minutes) pumped out. A type curve for raising the pit water level in an emptied pit is used. For example, in pits 3a and 8, the values of Ksat were assessed to be 2.2 cm/hour 3 and cm/hour, respectively. In this study, we illustrated the practicality of the bailout test in the characterization of soils/sediments properties of a bed of an ephemeral stream (wadi), provided a perched aquifer is within 2-3 meters depths, and the excavation and pumping equipment is at hand. We utilized the experimental bailout test data in a developed HYDRUS2D model. In this numerical model three different stages of seepage were studied: a) pre-pumping flow controlled by evaporation from the soil surface, b) seepage into an empty pit, the water level in which is zero, c) seepage into the pit where the water level is rising due to exfiltration of groundwater from the perched aquifer. HYDRUS-computed pressure heads for phase 2 (early stage of seepage into a completely emptied HYDRUS2D-approximated pit 8), day 1 of seepage which started from initial conditions of phase 1, which represented very slow evaporation from a modeled hemispherical pit of the same volume to a horizontal soil surface at the pressure head value of p=-1000 cm. The hemisphere in Phase 1 is at a constant piezometric head condition H=p+z= 65 cm, which correspond to the pre-pumping conditions. In Phase 1, water table is almost horizontal at the depth of z=-71 cm, slightly dipping from the pit axis outward (we assumed that seepage in all three phases is axisymmetric). In Phase 2, an empty pit is at the boundary condition of HYDRUS “seepage face” and the flow rate decreases very rapidly from 7.4*105 cm3/day to 2.3*105 cm3/day on day 2. In Phase 2 we assumed that the external boundary of the HYDRUS flow domain is at no-flow conditions and the pit remains always empty. In reality, the pit is not empty (after the moment t=6 min when the pumping stopped) and evaporation is much less than the exfiltration from the aquifer into the pit. Therefore, in Phase 3 we change the boundary condition at the external cylinder of the HYDRUS2D flow domain from the “no-flow” to a constant-H boundary. This condition models a perched aquifer, the storage of which is not reduced by exfiltration into the pit. Implementation of an experimental bailout test and mathematical modeling would be of high benefit for many areas where funding and logistics needed for regular well pumping tests are unavailable or prohibitively expensive.

ABSTRACT. Evapotranspiration (ET) is an important climate element, which highly affects the water cycle. Thus, a growing interest in calculating actual evapotranspiration (ET) for net crop water requirement in a specific area. However, there are many different methods for calculating and estimating the amounts of evapotranspiration. For many previous studies, remote sensing data were used as important sources and techniques to estimate various climate elements including evapotranspiration for large scale areas. This study has successfully applied the surface energy balance algorithm for land (SEBAL) to estimate evapotranspiration (ET) and Net Crop Water Requirements NWRCs for three date palm farms located in Al Zarqa-Jordan in one year. The analysis is carried out using Landsat-8 (OLI/TIRS) data, ASTER GDEM and reference weather parameters. Eighteen ERDAS models were prepared to calculate the various parameters related to solar radiation which are consequently used to calculate the hourly, daily and annually evapotranspiration in the study area. Results of pixel-wise calculations of the spatial variation of ET at date farms show the hourly and daily ET ranged from 0 to 1.15 mm/hr and 0.4 to 8.5 mm/day respectively in the Barakah-11 farm. While the monthly ET for the three farms varied from 22 to 225 mm/month that corresponding to NCWRs 1988.425 thousand m3. Overall, the results of the SEBAL method were efficient and logical for estimating the actual ET of the date palm trees.

ABSTRACT. In the Russian Federation, the main rice production is concentrated in the basin of the Lower Kuban, on 11 irrigation systems, with a total area of 250 thousand hectares, of which rice crops are 130 thousand hectares. With an actual average irrigation rate of about 20 thousand m3/ha, the total water supply for irrigation is up to 2500 million m3 as of 2020, which provides an acute water resources shortage for all water users in the Kuban River basin. The regular water shortages that occur in the Lower Kuban zone as a result of reservoirs effective capacity operation and the observed climatic anomalies that lead to economic damage to rice producers. The performed studies of water supply and water use on rice irrigation systems are based on a comprehensive analysis of long-term factual data collected and systematized for the Kuban River basin: water management balances of basin areas and Hydromet data (inflow and discharge from reservoirs, water intake to irrigation systems, levels and discharges at hydro posts); weather conditions for the main meteorological elements; agro-reclamation state of soils and technical condition of inter-farm and intra-farm irrigation and drainage network; water supply options and discharge on rice systems and crop yields. The study of actual production and natural factors influence on water scarcity included carrying out water balance calculations for catchment areas containing lands of rice irrigation systems, analysis of water balance dynamics by articles of inflow and outflow of irrigation water according to water use schedule. Based on the hydrological and meteorological forecast for the estimated month, as well as retrospective data, water losses during transportation through the canal network, evaporation, and infiltration were calculated on rice crops simulation models. Depending on the shortage of water resources occurring at various crop vegetation phases and weather conditions, the shortage of crops was estimated and on this basis, the optimal irrigation strategy was searched and the farmers water users requirements for the next planned water intake were adjusted. In order to implement the distribution of water resources to all water users, according to the submitted requirements, it is necessary to fulfill a number of hydrological and water management conditions that ensure the hydraulic units functioning and the required water intake. For this purpose, many water distribution possible scenarios are formed, controlled using the Kuban River hydrodynamic model developed in the MIKE 11 software. The results of multivariate calculations make it possible to estimate the amount of water shortage for water users, reservoir capacities and to ensure reliable water structures management for regulating water supply to irrigation systems and other water consumers. The matrix of solutions obtained using hydrodynamic modeling is analyzed in the Pareto Front Viewer software. Tradeoff solutions are discussed with the decision-maker and interested water users. The proposed approach to solving the problem of improving water supply and water use for rice irrigation systems is based on the development of an integrated system of tools for managing the water resources distribution, considering the efficiency of water use by agricultural producers.

ABSTRACT. The dynamics of desert landscapes are consequence of slow and long-term processes, one exception for such environments are flashfloods. Flashfloods in arid regions are highly variable in time and space and are difficult to predict and monitor. In Israel floods are characterized by durations of hours to days. Thus, systematic monitoring of flashfloods by remote sensing is a challenge. Short wave infra-red (SWIR) reflectance is sensitive to changes in soil moisture, therefore, using this spectral range one can monitor floods and flow events in arid regions even several days after a flood occurs. Earth observation satellites that use SWIR sensors are few, the first nano satellite carrying a SWIR sensor is BGUSAT. BGUSAT is a 3U (unit) cubesat, weighs 5 kg. The satellite carries a SWIR camera (wavelength 1550-1700 nm) onboard with 600 m spatial resolution. Due to its low Earth orbit (LEO), the satellite has a potential of one day revisit time, a critical parameter for DRM. This satellite is the first Israeli research nanosatellite launched from India on the PSLV-37 in 2017. Its mission is a research platform for demonstrating technology and scientific instrumentation. The satellite is a joint venture between Ben-Gurion University of the Negev (BGU), the Israeli Aerospace Industries (IAI-MBT), and the Israeli space agency (ISA). The objective of this research is to demonstrate the use of a single SWIR image, to detect and monitor the extent of floods and flow events in arid regions retrieved from a nanosatellite. As a case study we refer to the use of BGUSAT images in the Arava valley. In order to examine the feasibility of BGUSAT for such DRM application, we initially compared it to other active satellites with SWIR sensors. As a first step, the spatial resolution of SWIR images was degraded according to each sensor (MODIS, Landsat 8, Sentinel-2) to meet the 600 m\pixel resolution of BGUSAT. Followed by a pre and post change detection analysis of flood events. IWA's (Israel water authority) hydrometric stations data were used for three hydrological seasons (2017-2020) in the Negev as ground-truth along with field excursions using GPS validations and ground measurements with a portable spectrometer (ASD). Results obtained from various sensors imaging the Arava wadi following flash floods events, demonstrate high ability to detect soil water content and its spatial extent, highlighting the flow route. Moreover, owing to the decrease in the reflectance values, and using spatial statistics we were able to distinguish between flash floods and precipitation. It was found that this technique is applicable up to two days after the flood ends. This type of monitoring is essential for disaster risk management and reduction and is critical for infrastructure planning, drainage management and river rehabilitation as well as ecological interfaces. It is also the base for validating models predicting flash floods which save human lives and properties.

ABSTRACT. Hadejia town developed rapidly in the earlier 2000s and is the largest, populated and industrial city in Jigawa State of Nigeria. A large proportion of water for city use depend on the groundwater (borehole) availability. In this research, we assessed the groundwater quality through geospatial modelling and geostatistics innovation based on two different seasonal groundwater samples of 20 wells around the study area. The research focuses on utilizing an interpolated technique of kriging for generating color relief map/contour map together to produced thematic map of each parameter. The study also comparing and evaluating the amount of heavy metals concentration of groundwater between dry and wet seasons. The results indicate that certain elements like Fe, Pb, and Cr remain unchanged for both seasons. However, Zn, Mn and Cu shows increase in the wet season. It is recommended that the use of GIS should be encouraged to periodically monitor and display spatially the quality of groundwater.

ABSTRACT. Watershed prioritization has become of great importance for the sustainable management of essential resources such as soil and water. Morphometric analysis has been commonly applied to prioritize watersheds. This study presents a combination and integration of two different soil erosion prioritization methods that were applied on Yarmouk River Basin (YRB). The methods of morphometric analysis, and the Land Use/Land Cover (LULC) analysis were compared for erosion prioritization. The YRB was divided into 44 sub-watersheds. Twenty-one morphometric parameters were extracted and ranked on the basis of their values and relationships to calculate the compound factor (Cf), which was used to prioritize sub-watersheds in terms of sensitivity to soil erosion. It was found that YRB is a fifth-order drainage system, with a dendritic drainage pattern and elongated shape. Based on morphometric analysis resulted in categorizing about 41% of the YRB in the high and very high soil erosion susceptibility zones. For comparison purposes, LULC revealed that 88.6% of the basin was classified as having high-very high susceptibility to soil erosion. The sub-watersheds 1, 3, 4, 7, 9, 10, 11, 14, 20, 27, 28, 30, 32, 33, 35, 36, and 40 were found the most vulnerable to soil erosion based on both methods of analysis.

ABSTRACT. Given the water scarcity situation in the Middle East and North Africa Region (MENA), global strategies to increase food production should focus efforts on increasing production per unit resources, i.e. the combined increase of production per unit land surface area (yield expressed in kg/ha) and the increase of production per unit water used (water productivity expressed in kg/m³). Using ICT in agriculture provides a great aid to support information dissemination related to water requirements for irrigation, hence improving water productivity. The number of applications, which are being used and developed to help smallholder farmers and the agriculture sector, are increasing in line with water resources planning and management. The overall objective is to develop a mobile application to support the daily decisions on farm-related to water management and productivity. IRrigation Water Information Application (IRWI), provides farmers with information customized to their plots, weather conditions, and crop types and integrates geo-specific weather data, extract crop evapotranspiration values and net primary productivity from Earth observation product (for main crops in the Delta), and translates that technical data into readable irrigation schedules and crop health. The app specifies the amount of water required based on crop type, irrigation system, farm size, time of planting, water pump types and source of power and soil type.

ABSTRACT. Enhanced River Nile River Basin Monitoring For Improved Water Resources Collaborative Management and Development By Mohsen Alarabawy; Regional Hydromet Systems Coordinator and Dr. Modathir Zaroug; Water Resources Modeler at NBI - Entebbe, Uganda

River basin water resources planning, management and development at national, sub-basin and basin-wide level is significantly dependent on availability of complete set of credible data and shared information within the context of Integrated Water Resources Management and transboundary cooperation. Knowledge based and well informed decision making requires comprehensive information.

A basin that is shared by 11 countries, with population growth and scarce water, can be cooperatively developed and efficiently managed only if riparian states have a common understanding on the resource base, its state, trends, patterns, variabilities, phenomena and the threats it faces.

Furthermore, to meet the growing demands of water for food, energy and human consumption, the Nile Basin will continue to witness transformational levels of water resources development. Monitoring the entire Basin therefore is vital for realizing the gains from such development projects, for sustaining the water resource base and effectively managing environmental, social and climate change impacts as well as conflict prevention and basin stability.

The robust Nile Basin HYDROMET SYSTEM is the backbone of the Nile Cooperation; and shall significantly contribute to promoting riparian joint efforts towards enhanced management and development of our shared water and related natural resources in an efficient and sustainable manner.

This paper presents the role of basin monitoring in promoting and strengthening Nile cooperation and sound planning that sufficiently informs and adequately supports water and related resources planning. The paper highlights the following subject matters within the context of water security:  Strengthening joint monitoring of water resource base and shared understanding.  Earth Observation (EO) for river basins, State of knowledge and gaps, Hydro-Meteorological monitoring, State of the Basin Reports, Sharing data and building common knowledgebase.  Water quality management requirements and the state of affairs basin-wide.  Water resources development and proper identification of viable opportunities.  Socio-economic development needs including flood disaster preparedness, drought mitigation, soil erosion, coordinated management of water storage dams, agriculture, watershed and wetlands management, navigation, hydropower, fisheries, etc.  Improve basin resilience to climate change impact.  Alleviating disputes and mitigating conflicts through better understanding.

River basin monitoring is not only important for knowledge based water resources planning, efficient water resources management, harnessing water resources potentials and creating and promoting viable opportunities, and endorsing socio-economic development, but also vital for environmental sanctuary and sustainability; as well as creating resilience to climate change. The paper therefore demonstrates the valuable contribution of river basin monitoring towards water, food and energy security, environmental sustainability, climate changes adaptation and mitigation of impacts; through good transboundary governance, strategic analysis, adaptive policy instruments, and conversant modeling.

ABSTRACT. Flash drought is one of the great challenges faced by nature in the wake of climate change and during the first two decades of 21st century it has become more prominent, firstly termed in 2002. It consists of alarming conditions of change in normal moisture content of soil into drought condition within the span of weeks. These conditions exist due to either heat waves intensification or due to decrease in precipitation concentration in the atmosphere. This paper deals with the various studies conducted in the field of flash drought. Various definitions and criteria will also be drained out from various literatures and a wholesome definition is presented here. Flash drought condition in India through the reports of various national and international agencies is also discussed in the paper. Various parameter involving the measurement of intensity and duration of flash drought (FD) is also elaborated. This study also provides a general framework of approach towards FD identification, monitoring and rectification. Remote sensing and Geographic Information system are versatile tool for assessment of flash drought characterization and monitoring, are also discussed in this work. Various data providers such as NASA’s Soil moisture Active Passive satellite, North American Regional Reanalysis (NARR), MET data from India water portal and ERA5-Land reanalysis dataset were also conferred. Various methodologies related to flash drought identification are also discussed based on various seasonal timescale and monthly scale. This study will help stakeholders to gather useful information and develop deep understanding of these salient features of climate change impact on soil moisture.

ABSTRACT. Membrane filtration is an attractive technique to secure clean water in an energy efficient manner. In this regard, graphene derivatives are emerging candidates for efficient water treatment membranes, attributed to their unique nanochannel networks and robust chemical and mechanical stability (Geim and Novoselov, 2007). In particular, graphene oxide (GO) is regarded as a versatile platform for separating ions or contaminants, with the possibility of regulating the nanochannels through approaches such as cross-linking, pressure compression and molecular intercalation (Bang et al., 2020; Li et al., 2018), establishing an energy barrier originated from steric hindrance and electrostatic repulsion during permeation. Optimal interlayer spacing combined with appropriate charged properties could make possible attaining outstanding performance in terms of both parameters. We will present and discussed results concerning the synthesis and application of novel GO membranes for water desalination by combining experimental and molecular modelling techniques (Bang et al., 2020; Bang et al., 2021), following two different approaches: 1) Complexion of crown ethers and cation-intercalated GO composite membranes to tune the GO nanochannel for an effective desalination. 2) Forming amide-bonded polymer-crosslinked structures with controllable compressed and charged nanochannels. Following the first strategy, stable structures were found in which salt rejection rate could be increased up to 60% compared to the neat GO membrane, simultaneously achieving the adequate water permeance. In the second strategy, a simple pressurization process was used to adjust the interlayer distance of the polymer-intercalated GO structure, which varied the relative interaction distance of inserted molecules in nanochannels and the H-bond network inside them. The compressed channels cause a change in the polymer morphology during the insertion, forming different numbers of amide bonds; thus, obtaining narrower interlayer distances and simultaneously obtaining zwitterionic properties in the nanocapillaries. In this case, the salt diffusion rate was slower down up to 5 times compared to the neat GO membrane due to the modified channel, while maintaining a similar water flux. Overall, from both strategies it is inferred that interlayer spacing and appropriate membrane electrostatic properties can be controlled based on molecules intercalation, while making possible attaining outstanding performance of hybrid GO membranes in terms of water permeability and ions rejection. In addition to desalination, this methodology can be implemented for the removal of recalcitrant contaminants, including dyes and pharmaceuticals.

This work has been developed as collaborative bilateral project between the Korea Advanced Institute of Science and Technology (project 2018R1D1A1B07048233) and Khalifa University, (projects CIRA2018-103, RC2-2018-0024 and RC2-2019-007). References: Bang KR, Bahamon D, Vega LF, Cho ES (2020) Design of Sub‐Nanochannels between Graphene Oxide Sheets via Crown Ether Intercalation to Selectively Regulate Cation Permeation. Adv Mater Interfaces 7:1901876. doi:10.1002/admi.201901876 Geim AK, Novoselov KS (2007) The rise of graphene. Nat Mater 6:183-191. doi:10.1038/nmat1849 Li W, Wu W, Li Z (2018) Controlling Interlayer Spacing of Graphene Oxide Membranes by External Pressure Regulation. ACS Nano 12:9309-9317. doi: 10.1021/acsnano.8b04187 Bang KR, Bahamon D, Vega LF, Cho ES (2021) Synergetic effect of physicochemical and electrostatic strategies on ion sieving for polymer cross-linked graphene oxide membranes. Environm. Sci.: Nano 8:3312–3321. doi:10.1039/d1en00613d

ABSTRACT. The high quantity of sewage sludge (SS) generated during wastewater (WW) treatment poses a risk to the ecosystem as around 50-80 % of organic content, toxic and perishable contaminants are typically remaining in the sludge (Das et al., 2020; Liang et al., 2021). That depends on the operation conditions and the characteristics of the WW in the wastewater treatment plants (WWTPs). Moreover, recent studies have proven the presence of SARC-COVID in sewage sludge, which is a risk to the environment (Bardi and Oliaee, 2021). Therefore, the practice of dehydration and transportation of SS for land applications such as biofertilizer or for landfilling is not safe and it requires advanced thermal treatment (Zhang et al., 2021). Furthermore, all these processes increase the cost and the needed energy in the WW treatment. Sewage sludge treatment and reuse have become a serious concern in waste management and the presence of toxic pathogens such as SARS-COVID detection. Hence, thermophilic anaerobic digestion (TAD) could be an alternative technique to recover renewable resources from sewage sludge without spreading the SARS-COVID in the pandemic situation. In the biodegradation process, volatile fatty acids (VFAs) are the prior intermediaries for methane production. However, high concentration of VFAs leads to microbial stress, resulting in acidification and digester failure. In this regard, a batch thermophilic anaerobic digestion (TAD) was utilized to evaluate the VFAs production and biodegradation in sewage sludge. The comparison of the three sewage sludge’s as primary sludge (PS), secondary sludge (SS) and mixed sludge (MS) revealed that an increase in total volatile acids and methane yield was achieved using primary sludge. The maximum volatile acids production was on day 11 for both PS and MS with concentrations of 825 ± 0.5 mg/l and 237 ± 0.5 mg/l respectively. The dominant acidogenic byproduct was acetic which was the main mediator for methane production. Consequently, the methane percentage in PS was 77% ± 0.5 while in MS was 56 ± 0.5 %. At the end of the batch operation, the gas production decreased. These higher methane rates with PS digesters indicated that the production of VFAs was more critical for methane production. Furthermore, the methane yield from sewage sludge could be enhanced in this pandemic situation using thermophilic co-digestion and also by using bioelectrochemical anaerobic digestion. Because the high-temperature thermophilic biodegradation helps to destroy the SARS-COVID from sewage sludge. Primary and secondary sludges were collected from the primary and secondary clarifiers at Haya wastewater treatment plant (Muscat, Oman) and used as the feedstock source also as inoculum for the digesters. The experiment was established in lab scale using six bioreactors glass having 2L working volume. Each anaerobic bioreactor was equipped with a mechanical agitator for continuous mixing and with a lid containing two ports. The outlet of the gas was connected to a measuring cylider filled with water.

ABSTRACT. One of the major challenges in wastewater treatment using ultrafiltration is the membrane fouling caused due to deposition of pollutants on the membrane surface during the filtration process. Most of the time the fouling can be reversed easily by simple backwash, however, some of the pollutants can form a covalent bond with the membrane surface and cause irreversible fouling. In this study, Chitosan (CH) functionalized graphene oxide (GO) has been used to improve membrane hydrophilicity and reduce irreversible membrane fouling. Through FTIR analysis, the functionalization of GO with CH was confirmed. Incorporation of the synthesized nanoparticles in the polysulfone membrane matrix increased the average pore size of the membrane and increases membrane flux. Moreover, the hydroxyl and carboxylic functional groups in the nanoparticle increased hydrophilicity of the membrane and reduced irreversible membrane fouling.

ABSTRACT. Water is the elixir of life and without it no life can sustain on planet earth. There are many people in the world without access to clean water and are facing ailments of water-borne diseases. A lot of efforts are going on to eradicate potable water shortage but it keeps getting bigger with rapid urbanization and increasing population. The problem is particularly severe in hot and humid climates that have the perfect receipt for extracting water from air using solar energy. In this work the design of potable solar-powered water extracting and space cooling device is discussed. The designed device has the potential to keep running for 20 years through a square meter of photovoltaic solar panel extracting potable water at an average rate of 35 ml/hr @ 60% RH while maintaining the temperature of 2 cubic ft. space between 12-15oC. The design employed Peltier modules for bringing ambient air to it its dew point. The design was experimentally investigated at different relative humidity and the amount of water generated found to be strongly related to RH though small dependence also is seen with inlet airflow/temperature. The design has the potential to provide water in arid and off-grid conditions particularly reliable during natural disasters. The space cooling part can be used to store important medicines during power grid failure. The use of device reduces strain on conventional potable water supply and create awareness and utilization of abundant solar energy while keeping zero emissions.

ABSTRACT. There is a growing interest in the United Arab Emirates in the reuse of treated wastewater (TWW), driven by the growing water demand and the increasing inclination for sustainable solutions in water management. The application of TWW in food agriculture and non-food agriculture can present an efficient option for water management.

Earlier studies in the UAE have investigated the public acceptance of TWW reuse in various applications; the present work examines the farmers’ perspective. A sample of 300 farmers from the Al Ain region are questioned about their views on the advantages and disadvantages of TWW and their agreement or disagreement with its reuse in various applications. In addition, the farmers are asked about their willingness to use TWWs on their own farms and their willingness to pay for it; finally, they are presented with a choice experiment where they are asked to choose between TWW with assorted features and groundwater.

Analysis of the collected data provided interesting insights on the farmers' attitudes towards TWW and their economic valuation of TWW. Further regression analysis is performed to test the different hypotheses regarding factors affecting farmers’ awareness and acceptance of TWW reuse, including farm attributes such as crop diversity and availability of an alternative market for conventional irrigation water. Other farmers’ socio-economic characteristics are also shown to significantly affect their willingness to pay for TWW, such as age, education, share of household earnings from farming, and perception on TWW.

The results from the study are In line with other investigations in the region, however, some aspects of the statistical can help policy makers with the detailed information on farmers’ preferences, willingness to use and to pay.

Acknowledgement: This project was funded by a Start-Up grant from the United Arab Emirates University.

ABSTRACT. With increasing demand for good quality water and arable lands for food production, the underutilized nonconventional wastewater and arid lands can be used to grow a biofuel crop Arundo donax L., (Giant reed) in a contained and well managed sustainable bio-system. Our studies with A. donax in Australia have clearly demonstrated its high potential as a biofuel crop due to its high biomass yield, carbon sequestration and salt tolerance. In one study, A. donax recorded 45 tonnes (t) of dry biomass per hectare per year from a poor-quality soil under semi-arid climates when irrigated with saline wastewater. In many parts of the world, A. donax is often seen as a notorious weed to riparian zones however, in non–riparian arid regions it can be successfully grown as a low weed risk biofuel crop under strict weed management guidelines.

When established, A. donax is drought tolerant and can withstand salty water (up to 12 deci-Siemens/meter) and water logging. A. donax has been found to be more effective in treating wastewaters than the commonly recommended native reed (Phragmites australis).

Because of its high biomass yield, A. donax can remove large quantities of carbon and nutrients at high rates from wastewater over time. For example, it removed 21 t carbon, 528 kg nitrogen (N), 22 kg phosphorus (P) and 664 kg potassium (K) per year respectively from one hectare of land receiving 20 mega litres (ML) of wastewater and producing 45 t dry tops. Nutrient rich green biomass can be harvested and used as fodder for ruminants (e.g., camel, sheep, cattle, goat). When the biomass is used for bioethanol production, which removes carbon, oxygen, and hydrogen, then all the nutrients (NPK and micronutrients) left in the waste (fermented residue) can be returned to the plantations or to other crops as fertilizer and mulch on regular batch time basis of the ethanol factory process. A. donax can also act as wind break and a green screen (it can grow up to 5 meters high) around or near sewage treatment facilities, from where moderately saline wastewater can be used to irrigate such A. donax plantations.

A. donax yielding 45 t/ha receiving 20 ML of wastewater per year can potentially produce nearly 300 litres of ethanol/t of dry biomass in a process time of less than 24 hours, equating to production of 11,000 litres/ha/year. This is 2.5 times higher than irrigated corn (Zea mays) seed biofuel production from an equivalent land area. Together with other lignocellulosic feedstocks (eg., cereal straws), A. donax has high potential for establishing a new biofuel industry in many arid countries. An estimate made in 2010 from a South Australian case study indicated 22% return per annum, when bioethanol was priced at $A0.6/litre at the factory gate.

As fossil fuels become scarcer and higher in price, it is inevitable that the commercial potential of non-food crop such as A. donax grown on poor fertility soil and with saline water will increase in future.

ABSTRACT. Saturated hydraulic conductivity (Ks) is among the most important soil properties that influence the partitioning of rainfall into surface and subsurface waters and is needed for understanding and modeling hydrologic processes at the field scale. Field-scale variability of Ks is often assessed either by making local- or point-scale measurements using instruments such as permeameters and infiltrometers or performing field-scale infiltration experiments with natural/artificial rainfall and then relying on probabilistic models to quantify the spatial variability of Ks over a field. However, both these data collection techniques have limitations – the former requires numerous measurements across the study area and with the latter being fundamentally limited by the rate of applied water. As a result, existing methods are unable to fully resolve the spatial variability of Ks, over a field. In this study, a method that employed a field-averaged infiltration model and Monte Carlo simulations was used to obtain the possible range of distributions of Ks that would describe experimental observations over a field for a rainfall event. A Shannon information-theoretic approach was subsequently adopted to consolidate the ranges of Ks distributions over multiple rainfall events to yield the best range of Ks distributions. The method was applied to data from several rainfall-runoff events observed under natural conditions over an experimental field characterized by a silty loam soil and a small surface slope. Results suggest the existence of numerous parameter combinations that could satisfy the experimental observations over a single rainfall event, and high variability of these combinations among different events, thereby providing insights regarding the identifiable space of Ks distributions from individual rainfall experiments. Validation results showed that the method provides a realistic estimate of our ability to quantify the spatial variability of Ks in natural fields from rainfall-runoff experiments. Furthermore, the applicability of three commonly used in-situ point infiltration devices – viz., the double-ring infiltrometer, CSIRO tension permeameter, Guelph constant-head permeameter in the estimation of field-scale variability of Ks was investigated, using a Bayesian framework. Results clearly indicate the disparate estimates of Ks distribution parameters obtained from the infiltration data collected from individual instruments. Testing these distributions highlighted the inadequacy of in-situ point instruments in estimating the field-scale behavior of Ks.

ABSTRACT. Australia’s internationally recognized water reforms have been underpinned by a commitment to evidence-based decision making, achieved by investing in tools and methods that support the collection, analysis and presentation of water related data.

The Australian Government is committed to sharing its experience, tools and methods to assist government and water managers to build their capacity in water resource management and to address the issues of changing climates and increasing water scarcity. An example of this is the publication WaterTools: A Guide to three national level platforms that support the management of Australia’s scarce water resources (Carr et al. 2019).

WaterTools describes the development and application of three tools that are currently shaping Australia’s future direction for managing its scarce water resources. The three tools are:

• eWater Source – Australia’s National Hydrological Modelling Platform, a planning and operational hydrological modelling tool which integrates hydrology and policy/legal dimensions. • Digital Earth Australia (DEA) and Open Data Cube (ODC) technology for organizing remotely sensed information into analysis-ready forms to identify water availability and use. • The Bureau of Meteorology Water Forecasting Tools and the associated Australian Water Resource Information System (AWRIS)

These three tools represent the culmination of Australia’s investment in water management tools and play a key role today in the management of Australia’s scarce water resources. They reflect the lessons learnt over the last 30 years. A key feature of the tools is that they all have a national focus, they are not designed to meet local or niche needs, but to be adaptable and applicable across Australia’s diverse range of natural and built environments, climates and water management needs. Features that make them readily adaptable for use elsewhere in the world.

This paper highlights the application of these tools and explores opportunities for Australia to support other countries that are seeking to rapidly improve their water management to address water scarcity.

ABSTRACT. In the second half of the twentieth century, a cascade of reservoirs was constructed along the Angara: Irkutskoe, Bratskoe, Ust-Ilimskoe and Boguchanskoe, which were intended for producing renewable hydroelectric energy, transportation through the Angara and Yenisei Rivers, and for avoiding floods. The upper reservoir (Irkutsk Dam) is used to regulate the level of Baikal Lake. Operations are carried out using dispatch schedules (DS), developed on the basis of long-term hydrological series of the observed inflow and statistical analysis methods. Changing climatic conditions are impacting the effectiveness of the schedules. The study presents mathematical methods, algorithms and computational technologies that make it possible to form operational modes of the Irkutsk reservoir in various hydrological conditions, taking into account the hierarchy of priorities of water users' requirements based on dispatch schedules and multicriteria optimization methods. In the proposed computing technology, a statistical forecast is carried out for several years (tens of years) for the last years of the historical inflow, which reflect the ongoing climatic changes, and on this series the optimization task of the releases formation is solved, starting from a given initial reservoir volume. The optimization task is obtained with a dimension of about 1000 variables, solved by special methods developed by the authors (called as the “Pulsating Spring method”) in a classical deeply nonlinear setting. The original large-dimensionality optimization task is split into optimization of two-year subtasks that can be solved independently of each other. This decomposition makes it possible to use multitasking and multiprocessor computer modes. Water resourcet calculations were performed for various inflow series scenarios according to dispatch schedules and optimization methods for the modern requirements of water users. Multi-criteria analysis by statistical criteria showed that the operating DS does not provide control with normative reliability in recent years and in the low-water period, but the optimization approach does. In practical work, 11-year series of recurrence forecast were used, based on 11-year cycles of solar activity by Schwabe. An experimental proof of the correctness of the developed approach was carried out for an 11-year historical series from 1914 to 1924. The expected result was obtained: the security according to the proposed algorithm is higher than according to the DS, but naturally worse than when optimizing along the entire series. However, it is impossible to rigorously prove mathematically that the proposed algorithm gives better management than the DS for other reservoirs.Calculations were carried out using a program specially developed in the Visual Basic language with the Solver optimizer built into the Excel. Conclusions Research results showed that DS needs to be developed on the basis of hydrological series for the last 20-30 years, and not for the whole series and updated every 10 years. Toolkits have been created that allow for real-time reservoir management based on the optimization techniques proposed in this case study. The study also proposes methods for creating a long-term multi-year inflow forecast for performing optimization calculations.

ABSTRACT. Lake Tiberias is with an overall volume of 4,325 million m³ Israel’s largest fresh water reservoir, located in north-east Israel at an altitude of -209 m asl. In this semi-arid and water-scarce area, Lake Tiberias is an important source of water for Jordan. Around 50 million m³ of water is supplied to the country from the lake every year, increasing to 100 million m³ per year according to recent agreements. The water is conveyed to the Jordanian King Abdullah Canal (KAC), which is a major line of supply of potable and irrigation water to the Lower Jordan Valley (LJV). Given the water deficits in Jordan and Palestine, an efficient utilization of the available water is of particular importance. Since the important role of Lake Tiberias, this study analyzes whether and how the water supply of the lake to the LJV could be further improved and which data and information would be necessary. To address this complex task, one goal of this research study is to analyze the feasibility of a Multipurpose Management Tool of Lake Tiberias as Decision Support System for multi-objective discharge optimization. The water supply of Lake Tiberias is therefore analyzed according to the temporal and spatial water demands along the KAC using computer-based simulation and optimization processes. The study of the Multipurpose Management Tool demonstrates the potential feasibility of a predictive controlled operation of Lake Tiberias to improve the supply of water to the LJV. The developed tool calculates operation strategies for the lake to achieve defined objectives 110 km down the KAC. By means of such predictive control of the discharge, water is supplied as needed and can thus be used most efficiently. However, since this predictive control requires detailed forecast data about the temporal and spatial water demands of the LJV, a high level of information exchange and cooperation on both sides is needed. Besides the effective use of the available water, the supply of Lake Tiberias with desalinated water is being considered. Seawater would be desalinated on the Mediterranean coast and transferred by tunnel to the lake. In this context, an additional goal of this study is to carry out a hydraulic and energetic analysis of the hydropower potential at Lake Tiberias. The qualitative analysis of the desalinated seawater-driven hydropower at Lake Tiberias shows, that the potential energy of about 200 m between the coast and the lake could be used to produce substantial amounts of electricity. The resulting power of the hydropower plant is – depending on the discharge scenario and flow system – between 9.5 MW and 47.6 MW, while the produced electricity is between 80.2 GWh/a and 401.2 GWh/a. The hydropower can thus potentially contributes monetarily to water desalination. In addition, the coordination of hydropower with other energy sources, like photovoltaic, could optimize the usage of the produced electrical energy. Regarding the financial feasibility, only the investment costs of the hydropower plant would be accrued as the tunnel would be already in place to supply the lake.

(Presentation Type: Oral Presentation)

ABSTRACT. Extended Abstract (oral presentation), see submitted file

Due to increasing water scarcity in the middle east, Israel has been investing in large-scale seawater desalination projects and wastewater reuse systems since the end of the 1990s (Dreizin et al 2008). Palestine and Jordan, however, despite great efforts to use local water resources efficiently, still exhibit large yearly water deficits each year and countermeasures need to be taken (PCBS 2016; Whitman 2019). Furthermore, the effects of climate change and refugee movements due to civil wars in neighboring areas may increase the issues’ severity (Rusteberg et al 2019). The estimated annual freshwater deficits are about 323 million cubic meters (MCM) in Westbank and 712 MCM in Jordan by 2050. Due to the large set of possible technological solutions and the large spatial scale of the resulting transboundary water infrastructure solutions, the design of the water infrastructure system is a complex task. The water infrastructure system consists of seawater desalination plants and respective energy supply systems, water transfer pipelines and electromechanical equipment such as pumping stations. Furthermore, the topographic conditions in the region could favor the integration of a hydropower plant into the network. Therefore, a techno-economic assessment is essential within the process of identifying, assessing and selecting possible projects. For the construction of new or the modification of existing water infrastructure components, the associated costs are to be approximated at an early planning stage with reasonable effort in order to be able to differentiate between technical variants and evaluate them regarding their economic efficiency. We apply methods of fluid mechanics and cost estimation methods for the techno-economic assessment of integrated water resources management infrastructure projects (Geldermann 2014; Towler and Sinnott 2021).

ABSTRACT. The exploitation of rivers and hydropower reservoirs involves daily and strict water resources management that addresses the need of water resources managers to know the status of the sediment transport and deposition in order to determine the boundaries of the fairway and of the flooded areas and the status of hydropower reservoirs in their nature environment in order to plan water discharge activities and make informed decisions for maintenance, routine exploitation and emergency situations. We present ISME-HYDRO - an integrated system for sustainable monitoring of the water resources of rivers and dams that is based on a novel and disruptive approach for building web-based workflows combining different methods of AI, and integrating a vast range of heterogeneous data earth observation meteorological data, geospatial information, in-situ measurements and domain knowledge in a flexible, easily extendable and maintainable information infrastructures that enables superior interactivity with the data and ability for informed critical decision making. We demonstrate the fusion of linked data technologies, a form of explainable AI, providing semantic interoperability between the heterogeneous data, and deep learning architectures, a black box form of AI, that we apply to meteorological earth observation data and in-situ measurements to generate forecasts for a range of monitoring features such as river runoff, turbidity, water volume, water level and the like, adopting the method of EO4AI (earth observation for AI). The forecast data help generate hydrodynamic models for the river morphology and map the changes of the fairway on navigable rivers, using TELEMAC and advanced warnings for upcoming high water levels in dams about to cause overflow. The integrated system ISME-HYDRO allows four ways of querying historic and forecast data in all kinds of correlations, mixing meteorological, hydrodynamic and water economic data and geospatial information. The results come as synchronized table views, graph views, interactive maps and are exportable in single files. The system is supplied with data audit role where water economic data can be reviewed and modified and that can be connected with proprietary sensors for data acquisition. The information infrastructure underlying ISME-HYDRO is easily extendable and maintainable. It can be adapted as a self-serve web-based workflow for additional monitoring features or water bodies.

ABSTRACT. While there is almost universal access to drinking water across Australia, small regional and remote communities often experience significant and ongoing challenges in relation to the supply of adequate and safe drinking water. These challenges variously concern water supply security, water quality and water infrastructure.

Delivering water supply services to regional and remote Australian communities is a complicated and challenging task that is impacted by economies of scale, low-cost recovery and political reticence regarding consumers’ willingness to pay for improved water services.

The potential impact of climate change on water infrastructure in regional and remote communities has not been quantified yet however it is anticipated that water scarcity and water quality issues will be exacerbated, requiring the use of more advanced water treatment technologies and smarter ways of optimising and managing water systems to guarantee security of supply.

The Middle East presents an interesting comparison to Australia because it faces similar water scarcity challenges, provides water services delivery to a large number of small regional and remote communities and is at the forefront of a series of water innovations in operational practices, technologies and institutions.

Diagnosing the problem

Conventional and advanced water supply systems currently used in Australia have generally been developed for large cities. These systems have very high capital and operating costs, require a regular supply of various chemicals and daily intervention by experienced and well-trained operators.

In contrast water supply systems in small regional/remote communities are relatively simple, often providing only basic disinfection; biological and mineral impurities with potential health impacts remain untreated.

Existing advanced water treatment solutions, designed for larger cities, are not an economically viable solution for replication across Australia’s hundreds of remote communities and small regional centres. In addition to a considerable technological gap between urban and remote systems, there is consequent social and economic inequity and disadvantage.

Significant differences between urban and remote contexts (economies of scale, logistics challenges, long distances, etc.) don’t allow for transfer of innovation from urban systems to remote systems. There is potential for new insights to be gained from small scale systems overseas.

Research project

This research project, based on eight weeks of onsite investigations, face to face meetings and site visits held in Israel, Oman and the UAE in 2019, aims to gain new insights and to learn how other countries deal with water scarcities in order to fill a void in current Australian water treatment knowledge, experience and expertise.

By bridging the gap between large-scale, high-tech urban water treatment solutions and rudimentary remote water treatment practices the research project aims to facilitate the creation of a new and innovative model for remote systems.

This project outcome aims to have the potential to support strategic policy priorities, contributing to the development of resilient water supplies in regional and remote Australia.

Conclusion

The key findings from this research project have been developed into nine recommendations that may be applicable to regional and remote communities in Australia and are worthy of further exploration and discussion across the water industry.

ABSTRACT. In light of the disproportionate rise in world population in comparison to the availability of water resources, conserving this finite and scarce resource is a top priority. To add to this, rapid urbanization and climate change are also exerting pressure on the availability of water resources. This is even more important in arid regions. Buildings are a dominant contributor to the environmental footprint both in terms of energy and water consumption. Since a significant component of water use in buildings is attributed to cleaning, our aim in this work is to optimize number of cleaning cycles which would reduce water use, associated costs and the related environmental footprint. We present a technology enabled solution called ‘Dew’ to address the aforementioned problem. Dew comprises a hardware platform with a sensor that tracks visitors to washroom facilities passively in a privacy preserving manner and sends this information to a central database. This data is then analysed to identify optimization opportunities for reducing the number of cleaning cycles. In this paper, we elaborate on the design of this prototype, a small scale proof-of-concept pilot trial conducted in a building on our University campus and provide insights from this study. As will be shown later in this paper, Dew not only helps to conserve water and reduce environmental impact but can also help to reduce associated costs. Whilst findings from the small-scale pilot deployment show savings as high as 50% for two of the locations and 30% on average over the three locations considered in this study, there exists a massive potential for scaled-up deployments over a large number of buildings over a prolonged period of time. Dew also provides several auxiliary benefits including a reduction in the use of cleaning products and it can also be used as a tool for tracking and contributing to sustainability related regulatory targets.

ABSTRACT. The rising global demand for food, coupled with the limited resource of arable lands, is increasingly attracting attention to the world’s dryland regions. However, soils in the drylands are frequently not appropriate for agricultural activities. Hence, soil properties, mainly salinity, must be assessed prior to agricultural cultivation. Assessing soil properties in extensive areas is labor- and cost-intensive. In this study, we demonstrate the use of native plant communities as a proxy for soil properties This simple survey may potentially replace expensive field mapping and soil analyses. Our study, conducted in the arid environment of southern Israel, indicates that the distribution of native vegetation relates to the landscape’s geomorphic units and their specific soil properties. The soil salinity ranges from 0.8 mS/cm in the ephemeral stream channels to 25 mS/cm in the saline loess relicts. We found that the plant species Artemisia sieberi is indicative of low soil salinity, whereas Reaumuria negevensis specifies highly saline soils. Anabasis syriaca indicates soil thickness larger than meter while Anabasis articulata indicates shallow soil. After making the necessary adjustments, this method can be relevant for other dryland regions worldwide.

ABSTRACT. The G-Flows Project involved measurement, analysis, and modelling of geophysical, geochemical and hydrogeological data and their integration to help inform the groundwater resource potential for an arid region in the NW of South Australia. Coverage of airborne electromagnetic data identified the distribution, geometry and extent of a large regionally distributed buried palaeovalley system, known from previous studies to contain groundwater. Assessing the potential of this resource for community, environment and enterprises, formed the basis of an interdisciplinary investigation. The study involved the processing and inversion of the AEM data, it's interpretation against available drill hole lithology data, and subsequently against hydrogeological data acquired from targeted drilling of one of the larger palaeovalley systems. Water chemistry, environmental tracer analyses, and groundwater modelling were undertaken to better understand the rate of groundwater recharge and the movement of water through the landscape. Collation and reinterpretation of environmental tracer data with more stringent constraints, has helped to confirm and refine some previous characterisation of groundwater recharge and flow processes, and to refine groundwater recharge estimates for aquifers in key hydrogeological units. Groundwater recharge was estimated to be between 2–20 mm/year on the ranges and between 0.5 and 10 mm/year on the alluvial plains. Groundwater flow and age modelling were undertaken in-order to test different plausible conceptual models of the groundwater regime within the palaeovalley to aid the understanding of the available groundwater resource. Groundwater ages in the upper part of the valley‐fill sequences were ~900 years, but over 8500 years in the deeper parts of the palaeovalleys. The combined geophysics and groundwater hydrology work in G‐Flows built on the earlier work in the region and determined that highly episodic groundwater recharge occurs predominantly at the ranges in the north, where bedrock aquifers outcrop, but episodic recharge fluxes are also possible through ephemeral drainage lines traversing surficial alluvium and colluvium away from the ranges. It also established that alluvial/colluvial and bedrock aquifers are hydraulically interconnected via localised bedrock discharge recharging the alluvium/colluvium surrounding the ranges and via throughflow from the alluvium/colluvium recharging underlying palaeovalley and compartmentialised bedrock aquifers. Structure also compartmentalises the alluvial/colluvial fill in the palaeovalleys and appears to influence the groundwater flow paths, which may also be interrupted by nontectonic activity resulting from the reactivation of basement structures and the formation of hydraulic barriers in the overlying sediment package. The G-Flows project identified a significant groundwater resource contained within the aquifer systems of the region, but also determined that overall recharge rates are very low across the province. Hence long-term (decadal) groundwater extraction from these systems would have to be very carefully managed to ensure groundwater from these aquifers is just simply mined with longer term consequences for environment or community.

ABSTRACT. Water resources evaluation and supply planning is an important issue in the Middle East due to its arid and semi-arid climatic conditions. Therefore, in the context of the limited water resources, the development of a comprehensive tool which has the capability of displaying the results in a meaningful form for the user, will be very useful. In this study the focus is: (1) to use a decision support tool to assist in water management decision process in a systematic way, and (2) to assess the performance and potential applications of this tool. We introduce a recently developed decision support system, Sustainable Water Planner for Arid Regions (SUWAP), developed specifically for sustainable water planning for arid and semi-arid regions. The SUWAP enables to make a wide range of economic, technical and environmental conclusions in the process of long term water management approaches. We demonstrate that it works well and suggest that, despite its broad scope, it will be valuable for development of sustainable strategies and projects.

ABSTRACT. Located on the fringe of the Atacama Desert in southern Peru, the Caplina-Locumba basin (16,389 km2) presents a range of challenges for sustainable management of water resources. Surface water resources are limited, with critical conditions during severe periods of low rainfall. Water scarcity affects a wide range of users (people, mining, industry) and impact about 25,000 ha under irrigation. To overcome frequent water deficits, the basin is highly regulated, with inter-basin transfers, multiple reservoirs, and groundwater extractions. The water resources largely come from the Andean Plateau, with an average annual precipitation of 400 mm per year. The city of Tacna, with 350,000 people and located in the Pacific coast, receives on average less than 20 mm of annual precipitation.

The Regional Government of Tacna, which manages the Caplina-Locumba basin, entrusted the Australian Commonwealth Scientific and Industrial Organisation (CSIRO) to prepare a Drought Management Plan (DMP) for the basin. This comes at a pivotal moment for the management of water resources in Peru, with significant investments earmarked for monitoring systems and reform of regulatory and institutional frameworks. The DMP provides tools to support decision-making, guarantying security of supply to users (at acceptable levels) in order to allow planning and investment in industry, and to protect intrinsic environmental and cultural values. Underpinning the DMP is a Water Resources Management (WRM) model, built in eWater Source, that describes the hydrology of the surface and groundwater resources system, including operational rules and water-sharing protocols. The model simulates historical and existing conditions, as well as allowing for scenario assessments under changes in the climate, management and infrastructure development.

The WRM facilitated the choice of Drought Indices and thresholds, linking supply and demand regions for different users within the basin. The DMP approached management according to changes in risk to operations, in defined risk levels that adjust more gradually to alleviate drought circumstances, anticipating and being prepared for possible additional changes. The development of the first DMP for Peru, in the driest region of the country, has produced a series of innovative tools to improve the management of water resources under conditions of scarcity, and also contributed to the dialogue for a vision of the region’s sustainable development.

ABSTRACT. A short abstract will be provided in due course. An extended abstract is provided as an attachment. Please advise a deadline for final versions of both abstracts for publication purposes.

ABSTRACT. The COVID-19 pandemic has changed a lot of human behaviors that has seemed typical before the spread of this disease worldwide. Nonetheless, water consumption patterns have changed too due to lockdown procedures enforced by a number of governments worldwide that required people to stay at home to limit the spread of the disease, and the government of the United Arab Emirates that had this protocol in place. This paper looks into water consumption patterns in Dubai’s households during the pandemic and compares those patterns with ones before that of the pandemic. The emirate of Dubai has been chosen due to its characteristics as an urban city and its population’s behaviors has been highly affected by the pandemic, due to lockdown and other safety precautions taken by the city’s Government to combat the spread of the virus. Data of household water usage from the years 2018, 2019, 2020 retrieved from local water providing authority (DEWA) is analyzed to determine changing in usage. In addition, a survey was sent to a total of 100 houses these houses where composed of adults, adults with children, and single adults. The questionnaire included questions regarding the number of family members in the house, average monthly water bill, frequency, duration, way of usage, and routine of water usage before and after lockdown procedures in order to have a better look at water usage patterns in households on a daily basis. Noticeably, the overall average water usage per person in households has increased in 2020 where the pandemic precautions were strict. The significance of this study is that it provides an insight of how a certain change in consumers’ behavior could lead to a change in consumption patterns. By comprehending the reasons behind certain water consumption patterns, this could pave the way for setting strategies in order to promote a more sustainable consumption pattern.

ABSTRACT. Located at the end of Australia’s Murray-Darling Basin, the Coorong is a 140 kilometre long, shallow, brackish to hypersaline narrow coastal lagoon separated from the Southern Ocean by a coastal dune barrier. This Ramsar listed wetland provides critical habitat for many endangered migratory birds from around the world, threatened local wildlife and rare plants. It also plays an important role in natural fish migration and salt export from the Basin.

The ecological condition of the Coorong is in decline. Unsustainable water extractions in the Basin have led to significant ecological degradation. This has been accelerated and exacerbated by the Millennium Drought, with further risks posed from climate change.

Healthy Coorong, Healthy Basin is a joint State and National program comprising six projects, with two dedicated to engaging the local community. The objectives of engagement are to promote community advocacy and ongoing involvement by building community skills and knowledge to become caretakers of this precious wetland.

The local Coorong community itself is small and there is a need to engage an audience far beyond those who simply live near the ecosystem. The Coorong’s health is an important indicator for the health of the entire Basin, which supports Australia’s ‘food bowl’ and is home to more than two million people.

Community are engaged through public meetings, online forums, citizen science events, surveys and newsletters. Feedback and information gained from these activities is fed into research programs and infrastructure planning to allow genuine community and stakeholder input into decision making. A Coorong Partnership, comprised of key community leaders representing different areas of interest, also provides a valuable touch point on critical decisions and serves as a platform to test ideas, between broader engagement events.

Directly engaging communities in key decision points ensures support for the planned construction of infrastructure to improve water delivery and thus health of the system. More than 11,000 South Australians helped define the key objective for constructing infrastructure: ‘to improve the ecology of the system, using the most available scientific evidence, and given water constraints’.

Effort has been made to alert the community of advancements in scientific findings as they occur. Annual science forums and citizen science events have strengthened the community’s understanding of the importance of conserving the Coorong. 92% of attendees to Coorong citizen science events said they had an increased understanding of scientific survey practice and the biodiversity of the Coorong.

The Coorong is also of enormous cultural significance to its First Nations. First Peoples engagement has involved two-way knowledge sharing between First Nations Elders and project teams on Country, with National Park Cultural Rangers being directly involved in the research program. This approach ensures that infrastructure or management actions pursued minimises impacts to culturally important sites and has regard to Native Title rights and cultural heritage values.

It is vital that this ecologically important wetland and beautiful tourist destination is looked after for future generations for the benefit of First Nations, local communities, the state’s economy and visitors from across the world.

ABSTRACT. The irrigation management to distribute water in Distributary 2 (DY-2) Canal irrigable area of Sinthe Irrigation Schemes, Tatkone Township, Naypyitaw Council Area of Myanmar met relative success in 2020-2021 Summer Irrigation Season. It was initiated in early December 2020 and started on 16th March 2021 after the training interventions for the farmers of DY-2 Canal irrigable area to introduce irrigation planning and crop diversification based on the available water. The efforts of Irrigation and Water Utilization Management Department (IWUMD), DY-2 Water Users' Association(WUA) and Water Users' Groups (WUGs) of its watercourses and facilitators pave the way to ensure that the activities from planning to execution of irrigation. And irrigation monitoring and assessment were included to be sustained and keep the momentum of success throughout the irrigation management activities for the season. The steps governed and facilitated such as pre-irrigation, irrigation and post irrigation are the key drivers to ensure the achievement of operational WUA and its WUGs. As a brief the experience of last Summer Irrigation Season in DY-2 Canal irrigable area proofed the importance of Irrigation Governance. Observance of discipline, coordination and holistic execution of each and every stakeholder's activities in DY- 2 irrigable area could drive WUA, WUGs and IWUMD to resolve the bottlenecks in operation and maintenance of the irrigation system. Finally they could grow irrigated sesame 848.65 acres out of total DY-2 irrigable area 1,031 acres in 2020-2021 summer irrigation seasons. The above mentions are the some outputs and outcomes from the activities of Strengthening of Irrigation Management Institutions sub-component of the Agriculture Development Support Project (ADSP) of the World Bank in Myanmar. As a conclusion WUA and WUG are important coworkers and partners in sustainable irrigation development. Their capacities development should be a continuing activity and implemented by Irrigation and Water Utilization Management Department as a priority one.

ABSTRACT. The second State of the River Nile Basin Report (2020) was launched in February 2021. The report is part of the suite of basin monitoring tools (including, for example, the Nile Basin Water Resources Atlas). The report is aimed at critically assessing facts, trends, patterns, synthesis, and indicators for both the basin health and multiple biophysical conditions and also establishes the foundation and structure for basin reporting. The report gives policy makers, senior government officials, and the international development com- munity a basis for well-informed decision-making. Development of the report took 3 years as opposed to the originally planned 6 months development process. The causes of the delay are related to the challenges usually experienced in managing transboundary water resources. First, data belongs to member states and, where trust and confidence are low, the countries are usually not willing to share it. Secondly, the increased availability of free datasets is sometimes a challenge in a transboundary context as such data, before they are used, need to be thoroughly validated to the satisfaction of member states. The validation process can take many months and may need to be restarted when unacceptable data are discovered. Finally, language used in such a report needs to be consistent with objectives of the report, promotes cooperation among member states (as opposed to conflict), and should be laid out in a manner that is acceptable for all countries. The purpose of the presentation will be to share experiences on how the process of developing the State of the River Nile Basin Report (2020) evolved and how consensus among the member states was achieved. The contents and structure of the report are guided by the six priority areas of the Nile Basin Initiative (NBI) 10-year Strategy (2017–2027), which advocates key strategic directions that were agreed by the NBI member states and sets the ambition for delivery of impact on the ground. The priorities include (i) water security, (ii) energy security, (iii) agricultural development and food security, (iv) environmental sustainability, (v) climate change, and, (vi) transboundary governance. For each of these themes, the current state, main trends, drivers of change, and management responses have been identified.

ABSTRACT. The UAE is making significant progress in developing the Controlled Environment Agricultural (CEA) production system based on Greenhouse and introducing technologies like hydroponics. It is estimated that some 10,000 greenhouses and 1000 hydroponic farms exist in Abu Dhabi Emirate alone. These modern farming techniques aim to produce a higher amount of crop products using minimum inputs like irrigation water. The objectives of this study of hydroponic farms include analyzing their productivity and economic efficiency; assessing their impacts on energy and water consumption; to identifying the operational challenges the farms face. Primary data was collected through sample surveys and on-farm measurements. Preliminary profitability analysis of a typical sample hydroponic farm shows a net profit of 2,692 dirhams/ square meter, 682 dirhams per square meter, and 949 dirhams/ square meter for tomatoes, cucumber, and capsicum, respectively, for a growing cycle or season. This is a significant improvement in farm productivity. Economic profitability analysis considering water use for irrigation and for cooling greenhouse is underway. One major cost of hydroponic farms is water consumed in cooling the greenhouse with using evaporative system (pad and fans). A study made earlier by Fadel (2014) found that farmers use more water, than needed for irrigation, for greenhouse cooling. In this study, a measurement made at one hydroponic farm shows that 5.4 liters of water is used per square meter per day for cooling a greenhouse.