ABSTRACT. Water management is one of the most pressing global challenges for sustainable development, and this issue is particularly important for arid regions. Water is a fundamental human necessity and essential to improve social equity, promote broad economic development, and support robust environmental systems. Global freshwater use has been identified as one of nine “planetary boundaries” regulating the safe operating space of Earth to support humanity. Global goals for sustainable water management are outlined in the United Nations Sustainable Development Goals, and specifically SDG 6, which is to “ensure access to water and sanitation for all.” Furthermore, progress on SDG 6 is likely to have positive co-benefits for ending poverty and hunger (SDG 1 and 2), ensuring health and well-being (SDG 3), and promoting economic growth (SDG 8). Despite significant progress, however, billions of people throughout the world still lack access to sustainably managed water and sanitation services, and emerging challenges, including climate change, are leading to increased and complex risks. While sustainable water management involves scientific, technical, and engineering solutions, these important contributions alone are insufficient. Ensuring sustainable water futures for all will require new approaches to creating transdisciplinary knowledge about environmental and social processes. Furthermore, sustainable water management requires decision-making under conditions of deep uncertainty about future environmental conditions, sociopolitical scenarios, and the evolving of needs of an increasingly interconnected global society. This involves inclusive approaches to collaboration between scientists, engineers, managers, policymakers, Indigenous peoples, public, and a diverse range of stakeholders. The goal is to cooperatively produce relevant knowledge and adaptation pathways, promote social learning, justice and equity, and build enduring social and institutional capacity. People in arid regions have been innovating new approaches to sustainable water management for millennia and have the opportunity to provide global leadership for sustainable water futures for all.

ABSTRACT. Arid regions (deserts, arid, semiarid, dry lands) of the world are typically in subtropical areas, including central and western Asia, the Middle East, Africa, North and South America, central and northwest Australia. They constitute about 35% of land areas of the world and are normally characterized by rainfall scarcity, higher temperatures and evapotranspiration, lower humidity, and a general paucity of vegetation. They are among the world’s most fragile lands, caused by continuous drought and increasing overexploitation. Overexploitation of forests by overgrazing is one of the main causes of soil degradation in arid and semiarid regions and its transformation into a desert. The soil is categorized according to the amount of annual precipitation: ultra-dry (less than 100 mm), with almost no or no water in this soil, and dry (100–250 mm) and semiarid areas (200–500 mm). Lack of water availability, generally due to low precipitation, leads to arid ecosystems. These characteristics render arid land hydrology quite different from that of other areas. Defining emerging areas in arid lands hydrology is a challenge. Some of these areas are social hydrology, ecohydrology, remote sensing hydrology, nuclear hydrology, global hydrology, hydrology of climate change, and hydrology of disasters. Many of the areas have emerged as a result of recent developments in data science, tools of analysis, fields of application of hydrology, modelling technology, and discovery of new concepts. This presentation provides a snapshot of areas deemed to be emerging in arid lands hydrology

ABSTRACT. Due to the limited traditional water resources in arid regions, many countries in the area heavily rely on shared transboundary surface and groundwater resources. For instance, all nations in the MENA region share at least one aquifer, and 60% of surface water resources are transboundary. The countries that depend most heavily on these shared waters also have the highest percentage of water that originates outside of their boundaries. Transboundary water agreements often rely on historical data and averages, rather than considering the percentage of water flows. This can make it more challenging to address the impacts of climate change, which are difficult to predict. Effective management of transboundary water resources requires open, unbiased, and productive relationships among all stakeholders. Since many arid countries lack perennial streams or surface water, it is important to adapt water security calculations and formulas to the unique physiographic characteristics and water resource systems of these regions.

ABSTRACT. Uranium occurs in varying concentrations in groundwater globally. Due to its toxicity and radioactive decay products, monitoring the concentration of uranium in groundwater is vital for the sustainable use of this natural water resource. The common naturally occurring isotopes of uranium are U-238 (99.27%), U-235 (0.72%) and U-234 (0.005%) with traces of U-236 and U-233. The permissible limits for toxic and radioactive hazards in drinking water were set at 30 micrograms per liter (µg/L) for total uranium and less than 1Bq and 10Bq for U-235 and U-238 respectively by US Environmental Protection Agency (EPA) and the World Health Organization (WHO). Uranium acquires many ionic valence states in natural water, but the most common one is the hexavalent (uranyl ion, UO2 2+) valency in combination with oxygen. In the investigation presented here, we report on the distribution of U-238 and U-235 in groundwater samples covering most of the UAE. A wide range of total dissolved solids (TDS, 200-110000 mg/L) and pH (6-9) characterize the groundwater. The concentration of U-238 ranges at 20-65000 ng/L and U-235 at 0.3-450 ng/L. About 95% of the groundwater samples lie below the permissible limits for toxicity and radioactive hazards. The spatial distribution of the isotopes was mapped using a combination of clustering technique and artificial intelligence prediction. The occurrence mode and amount of uranium isotopes in groundwater are mainly controlled by the lithology of the aquifers, residence time of groundwater in the aquifers and mixing between different groundwater sources (shallow and deep). The aquifers are composed of four major lithological units including carbonates, igneous and metamorphic rocks, Quaternary alluviums and sand dunes. The depth of groundwater table in these aquifers varies from a few meters to more than 100 meters. The residence time, age, of the groundwater in the aquifers is not well defined, but it may vary from a few months to thousands of years. The mixing between different sources of groundwater can be investigated using other chemical and isotopic tracers together with uranium isotopes. The effect of all these factors on the distribution of uranium isotopes in the groundwater and the use of uranium isotopes for groundwater tracer technology are discussed in the presentation.

ABSTRACT. Climate change, extreme temperature, and minimal precipitation has resulted in significant deterioration of groundwater quality. Al-Baha region in Saudi Arabia has been affected by climate change due to its presence in unconfined shallow aquifers. Therefore, the objective of current study was to evaluated the quality of groundwater in Al-Baha region as affected by climate change. For this purpose, 88 groundwater samples were collected from Sarat Al-Baha and analyzed for hydrochemical characterization. Out of 88 samples, 80 samples demonstrated that the concentrations of nitrate and heavy metals were within permissible limits for drinking water. Only 7 samples out of 88 showed poor to very poor drinking water quality owing to the occurrence of arsenic and nitrate. None of the samples showed sodicity hazard, while majority of the collected samples exhibited medium to higher salinity hazard. Most of the minerals in the samples were under-saturated as indicated by saturation index, suggesting a salinity hazard. Overall, >90% of the samples were observed to be unsuitable for irrigation owing to the presence of salts in higher amounts. Due to climate change, Al-Baha region is experiencing a significant reduction in precipitation and an increase in the temperature, which has resulted in higher salts concentration in groundwater. Appropriate management of the groundwater including minimal discharge and utilization must be carried out in AL-Baha to lessen the impacts of climate change.

ABSTRACT. The islands, due to their geographic condition of limited territory, are also limited in the resources available to them for the development of regular life. Spain counts with an archipelago that is itself an outermost European region, the Canary Islands, with unique characteristics due to its richness in groundwater and the use of desalination to support the water demand, which rises mainly due to agriculture and the tourism sector. In addition, this archipelago also suffers from further matters such as the contamination of coastal aquifers as a result of seawater intrusion, deficient wastewater treatment and a significant increase in the desalination of seawater, with the consequent energy demand that this entails. Therefore, this article has analysed the current situation of the resources in the Canary Islands, as well as the future challenges that arise, in a scenario of climate change, where temperatures are expected to increase in Spain.

ABSTRACT. Agriculture is seen as a great water consuming activity. However, the growing world populations demands more food availability, and crops need water to achieve higher productivity, even the well adapted ones. The climate change effects that are felt all over the globe impair soil-water-crop relations and endanger food security. On the other hand, agricultural activities, and mainly substantial chemical fertilizer use, can threaten water bodies due the loss of nutrients. The high concentrations of nutrients can ultimately cause eutrophication and several disturbances in the aquatic systems: depletion of oxygen, alterations in flora and fauna, endangering the habitats and biodiversity, and reduce water quality. Nutrients are essential to crops and the substances that effectively provide nutrients to plants are designated by fertilizers. In the last few years, nanofertilizers are been used to provide the same nutrients, but in more precise and efficient ways. Thus, soil properties and health are also improved as nanofertilizer can release nutrients at a slower rate than conventional fertilizers, opposing nutrient imbalances, contributing to better soil fertility and organic matter content, amending problems in soil structure, and contributing to food quality and safety. For this work, data were obtained primarily by research papers (Web of Science, Science Direct, Frontiers, MDPI and Springer databases) supplemented by governmental institutions’ and relevant international institutions’ publications. Here, the contribution of nanofertilizer use to water resource resilience and water-crop sustainability, is highlighted. Water quality reduction due to fertilizers cause irrigation water to have higher amount of soluble salts that directly injure crop root system, undermining water and nutrient uptake. This reduces plant grow, deformations on yields, and can lead to entire crop losses. Besides the direct contamination of water bodies by excess of nutrients, in increasing mean temperature and extended drought periods related to climate change, soils suffer several challenging alterations that alter soil-water-crop dynamics: salinization, soil moisture content, water-holding capacity, particle size, evaporation rate increase, mineralization rate increase and lower capacity to sequester C. In this scenario, how can nanofertilizers contribute to protecting water resources and improve soil-water-crop dynamics, contributing to food security? Nanofertilizers provide nutrients to crops in very efficient ways, using less inputs and providing it to the plants in a controlled or slow-released way according to crop demand. This ability opposes nutrient imbalances in soil by synchronizing macro and micro nutrients, contributing to better fertility, improved organic matter content and soil structure. The use of nanofertilizers improves crop nutrient and water use efficiency (NUE and WUE), reducing risks. The utilization of nanofertilizers assure the efficient use of fertilizers, in appropriate timing and rate of delivery, reducing the negative effects of chemical fertilizer to water resources and opposes nutrient imbalances in soil, improving its structure and improving water holding capacity and water use efficiency by plants, crucial for crop development and food production.

This work was funded by the Fundação para a Ciência e Tecnologia under the scope of Raquel Saraiva’s PhD grant 2020.06559.BD, project PTDC/CTM-REF/2679/2020, UIDB/04462/2020, the UIDB/04129/2020 project LEAF—Linking Landscape, Environment, Agriculture and Food Research Unit.

ABSTRACT. The High Atlas Mountains encompass one of the most important water resources in northwest Africa. However, a thorough study detailing the interactions between mountainous wetlands and snow cover, the evolution of their extent over time and space, and their implications on water resources in northwest Africa is still lacking. In this study, we propose a multi-disciplinary approach to investigate the dynamics of wetlands in the High-Atlas Mountains. We focus on characterizing the water cycle components in the region (e.g. evaporation, precipitation, surface water, groundwater flow) using isotopic tracers and over different timescales. Several field work and sampling campaigns were carried out over different seasons to investigate the interactions between snow events, snowmelt, surface water at the lake of Ifni and the neighboring springs. The stable isotopes data, based on a local meteoric water line and an altitudinal gradient indicate a local recharge of the lake from snowmelt and springs that are embedded in the lake. Furthermore, at the watershed level, the lake of Ifni is the most important source of groundwater recharge outside of the snow season as shown by spring water samples in the downstream. Our results highlight the substantial contribution of snowmelt from the Atlas Mountains to the recharge of the main aquifers in Morocco. Future climate projections will further showcase the relevance of our study to get unprecedented insights on future water resources in Northwest Africa. Our study will serve as guidance for decision-makers to improve water management and climate action strategies in the region.

ABSTRACT. Seawater intrusion (SWI) occurs naturally in most coastal aquifers around the globe. This phenomenon is predominant specifically in Arid and semi-arid regions whenever the groundwater extraction significantly surpasses the natural replenishment process. Climate change might contribute to elevated sea levels, thereby exacerbating the landwards encroachment of SWI. Among others, hydraulic and physical barriers are the most effective mitigation measures used for SWI management. The current work evaluates the efficiency of the suggested mitigation measures under sea-level rise. An idealized conceptual model is utilized for the sake of the current investigations. FEFLOW was used to conduct two-dimensional vertical simulations, considering steady-state conditions. The sensitivity analysis was done through changing barriers’ location while inducing sea level rise and evaluating the percentage change in SWI. Preliminary results have shown that physical barriers outperformed hydraulic barriers in alleviating SWI under sea level rise conditions.

ABSTRACT. Pakistan is classified as one of the countries facing severe water stress globally, with its water supplies being highly susceptible to climate variability, climate change and contamination. Assessing the water pollution in rivers, which poses a threat to the interconnected ecological community, is a fundamental aspect of sustainable management. Hence, the current investigation aimed to evaluate the water quality of the Jhelum River basin (JRB), which serves as a crucial water source for irrigating around 6 million hectares of land in Pakistan and facilitating hydropower generation. For that purpose, sixty water samples were collected from the JRB and assessed for their physicochemical properties using a multi-parameter analyzer and atomic absorption spectrophotometer. Two primary methods, spatial variation analysis and multivariate statistical techniques, were employed to analyze the water quality data. The preliminary examination indicated that the levels of various physicochemical parameters, including pH, electrical conductivity, total dissolved solids, chloride, nitrate, sulfate, bicarbonate, turbidity, calcium, magnesium, potassium, and sodium fell within the safe thresholds for drinking and irrigation water as set forth by the World Health Organization (WHO) and the Pakistan Environmental Protection Agency (Pak EPA). The sodium adsorption ratios (SAR) in the examined water samples were determined to be less than 3.12. Statistical analyses revealed that the elemental contamination of the physicochemical parameters of the Jhelum River and its tributaries comes from natural sources (deterioration of bedrock from the Pir Panjal Ranges in the headwaters to the Siwaliks in northern Punjab) alongside some anthropogenic influences as well. However, the water quality of the Jhelum River and its tributaries in the upper Indus basin is safe and fit for drinking, domestic, and irrigation purposes; consequently, this study strongly recommends these usages in Azad Kashmir and northern Punjab, Pakistan.

ABSTRACT. Climate change has rendered climate adaptation a critical topic of discussion across all sectors in recent years. The Adaptation Strategy to Climate Change in Taiwan and the Spatial Planning Act both provide actionable guidelines for spatial planning under climate change. Past discussions on climate change in the context of agricultural development have predominantly focused on temperature changes as well as the development of adaptation strategies associated with agricultural species and rarely touched on spatial planning. In this study, flood impact maps from the Taiwan Climate Change Projection Information and Adaptation Knowledge Platform (TCCIP) were used to simulate extreme rainfall, namely the level at the 95th percentile of maximum 24-hour accumulated precipitation, in Yilan County, Taiwan. The amount of precipitation from extreme rainfall in the county was predicted using a regional mean model, which yielded 502 and 621 mm of extreme rainfall for the base period (1979–2008) and the mid-century period (2039–2065), respectively. However, the intensity of disaster as a result of extreme rainfall may differ in the mountainous and plain areas due to the terrain features in Yilan County. Therefore, following a literature review, a case study, a geographic information system overlay analysis, and in-depth interviews, the levels of extreme rainfall in a mountainous area and a plain area in Yilan County were predicted based on traceable data generated using the TCCIP flood impact maps. According to the prediction results, the levels of extreme rainfall in Datong Township (mountainous area) were 635 and 904 mm for the base and mid-century periods, respectively, and those in Jhuangwei Township (plain area) were 335 and 522 mm, respectively, for the base and mid-century periods. The data were then used to investigate the impact of extreme rainfall on the agricultural development zones (designated under Yilan County’s spatial plan) in the study areas and potential effect on agricultural production values. The main findings of this study are as follows. (1) The dominant crop in Jhuangwei Township (plain area) was rice, and its production was preliminarily predicted to drop by 921.86 t as a result of extreme rainfall in the midcentury period, during which the flood level was expected to exceed 0.5 m and the flood area to increase by 658.32 ha. This drop of production translates into a loss of NT$22.58 million per year based on the Taiwanese Agriculture and Food Agency’s average purchase price statistics for rice over the last 10 years. (2) Cabbage and watermelon were the dominant crops in Datong Township (mountainous area) and were mostly grown on riverbanks or slopes. In this area, the extreme rainfall was expected to reach 904 mm in the midcentury period, which imposes a high risk of substantial agricultural loss. The empirical results could provide a basis for strategic national spatial planning that addresses extreme rainfall under climate change and serve as a reference for developing resilient adaptation strategies.

ABSTRACT. Palestine, located in the eastern Mediterranean region, exhibits a varied climate due to its geographical positioning and diverse topography. Coastal and semi-coastal regions, including parts of the West Bank, display a Mediterranean climate characterized by mild, moist winters and warm, arid summers. As one moves inland within the West Bank, the climate shifts from arid to semi-arid conditions, marked by hot, arid summers and relatively mild, wet winters. This climatic context serves as the foundation for the current research. This study focuses on a sub-catchment in the northern region of Palestine known as Al Badan, which is part of the upper Faria part from the main Faria catchment. Covering an area of about 90 km² and housing a population around 48,000 residents, this sub-catchment heavily relies on groundwater as its primary water source, a factor significantly influenced by precipitation patterns. The research employs the Mann-Kendall test to evaluate the temporal trends of two key climatic parameters over the past three decades (1990-2020): annual total precipitation and mean annual temperature. The analyses aim to provide empirical evidence of climate change trends in the sub-catchment. Results show a significant finding regarding the evolving climate dynamics in the area. Firstly, the analysis of annual precipitation data has revealed a significant decreasing trend. The Mann-Kendall Statistic, calculated at -0.258, along with a two-sided p-value of 0.039, confirms the existence of a statistically significant decline in precipitation levels during the specified timeframe. This trend is further quantified by Sen's Slope, which is computed at -5.48, indicating a reduction in annual precipitation of 5.5 mm. Simultaneously, the analysis of temperature data has identified a discernible and statistically significant temporal pattern. The trend line slope, computed at 0.078, along with an exceptionally low p-value of 0.0004, provides obvious evidence of a rising temperature trend over the study period. These findings carry substantial importance, as they unveil significant changes in both precipitation and temperature patterns, contributing to an enhanced understanding of climate dynamics in the sub- catchment. These changes have direct and multifaceted implications for local communities, agricultural practices, and the broader socio-economic conditions. Therefore, it is imperative for stakeholders and policymakers to collaborate in developing adaptive strategies to address the multifarious consequences of climate change. This includes devising sustainable water resource management tools to fulfill the increasing water demand under uncertain supplies. Such initiatives are crucial for maintaining water security in the face of shifting climatic conditions and safeguarding water needs for different uses in the study area.

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 and is declining rapidly due to over exploitation. Agriculture in the region is facing multiple challenges including low water use efficiency, extreme wind and water erosion, increasing climate extremes, decreasing soil health, declining biodiversity. Strong winds aggravate frequent drought and heat stress in the region. Therefore, for the last 15 years, we are assessing diverse approaches to improve sustainability of irrigated agriculture in the region. 1). Crop Diversification and Deficit Irrigation Management: Our interest is to understand root systems, water use patterns, resiliency, and yield formation of desert adopted crops like guar, safflower, winter and spring canola, etc., under increasing uncertainty in growing environment. Skipping irrigation before flowering or after flower initiation has the potential to decrease irrigation water use by 24 to 64%, but yield penalty can be higher if reproductive stage is stressed compared to vegetative stage. In more drought tolerant crops like safflower yield reduction was less (19-23%), while it was more than 50% in spring and winter canola depending on the growth stage. Yield reduction of desert crop ‘guar’ to deficit irrigation varied more (0 to 38%) and depended on growing season and growth stage. The projects also assessed benefits of deeper and more extensive root systems on water extraction pattern, and seasonal biomass production and water use efficiency of alternative crops. Thus, selection of crops, their root systems and understanding sensitive growth stages influence deficit irrigation management strategies and water saving in the region. 2. Alternative Cropping Systems: We need novel cropping systems that not only improve water cycle efficiency but also conserves natural resources, improves productivity, biodiversity and offers many other benefits. One such system is ‘Circular Buffer Strips of Native Perennial Grasses’. The concept is novel, where dryland or unirrigated 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. Each component of the design, 1) perennial grass species mixture, 2) buffer strip, 3) circular design and 4) concentric circles are expected to add or improve benefits to irrigated food production system. Overall goal is to reduce stressors like desiccating wind, heat and pests entering into the system and resources like water, nutrients and agrichemicals leaving the system to improve sustainability and resiliency of the system. Multiyear study showed improvements in conserving heavy intensity rainfall (90-138%), reduce crop stress (10-13%), improve corn/maize crop productivity (4-20%) and short-term water use efficiency (50-63%). At the same time, the system is also improving biodiversity, soil health, carbon sequestration and reduces greenhouse gas emission and soil erosion. If multiple strategies and multidisciplinary teams are used to address water issues more effectively, we can sustain Ogallala aquifer longer.

ABSTRACT. Borehole water samples were collected from three points within abattoir wastewater discharge point with point 1 at 30 meters, point 2 at 50 meters and point 3 (served as control) at 200 meters away from the point of the abattoir wastewater discharge. Wastewater from the abattoir is channeled into a burrow pit as the means of waste discharge. The borehole water samples and the abattoir waste water were analyzed to evaluate effect of the abattoir waste discharge on the physicochemical, heavy metal and bacteriological quality of the surrounding borehole waters. The data obtained were subjected to statistical analysis using Statistical Package for the Social Sciences (SPSS) version 2.0. The result of the physicochemical properties of the waste water analyzed showed that the pH (6.45) was below World Health Organization (WHO)Standard, the Total dissolved solids (TDS) (795.00mg/l), Electrical conductivity (EC) (795.00u/cm), Turbidity (68.50NTU), Biological oxygen demand (BOD) (296.25mg/l), Total Hardness (127.85mg/l) were higher than the acceptable standard stated by WHO. The acidity (13.61mg/l), Chloride (57.98mg/l), Nitrate (8.92mg/l), Phosphate (5.68mg/l), Sulphate (23.93mg/l), Dissolved Oxygen (0.30mg/l) of the abattoir waste water fell under WHO Standard. The result of the heavy metals showed that Zinc (12.55mg/l), Iron (7.78mg/l), Lead (0.76mg/l), Arsenic (0.48mg/l) were all higher than the WHO Standard. The result of the Bacteriological quality of the waste water showed that the abattoir waste had a total Coliform load count of 7.8*107, E. Coli and Salmonella load count of 2.0*107 and 2.5*107 respectively. While the result of the physicochemical properties of the borehole water samples shows that the pH of the samples (4.23 – 5.83) were below acceptable standard stated by WHO, while the TDS (54.50 – 77.0mg/l), EC (109.00 – 157.50u/cm), turbidity (0.67 – 0.85NTU), acidity (30.20 – 50.00mg/l), chloride (19.19 – 22.27mg/l), nitrate (Not detected (ND) - 0.03mg/l), phosphate (0.72 – 1.45mg/l), Sulphate (4.25 – 6.81mg/l), total hardness (25.66 – 25.93mg/l), dissolved oxygen (4.80 – 8.93mg/l) and BOD (0.70 – 0.95mg/l) of the borehole water samples were within the stipulated acceptable limit of WHO. The result of the heavy metal concentration showed that the zinc (0.68 – 1.25mg/l) and iron (0.08 – 0.20mg/l) concentration of the borehole water samples also fell within acceptable limit. Arsenic and lead were not detected in the borehole water samples. The result of the bacteriological quality showed that the borehole water samples had total viable load count that was higher than the stipulated standard. Coliform was only detected in point 1 borehole water which indicated presence of water borne disease therefore purification of water in this area is highly recommended before consumption.

ABSTRACT. Urban farming is recognized as a Nature-based Solution for advancing urban sustainability. The practice of cultivating crops within city limits not only bolsters food security but also yields a plethora of ecosystem services. Additionally, it fosters social connections among urban inhabitants, thereby enhancing community cohesion and resilience. Taipei, since 2015, has been at the forefront of this movement through its Taipei Garden City Program(TGCP), establishing of 731 gardens. This initiative has positioned Taipei as a global pioneer in revitalizing urban farming practices. However, this endeavor has raised concerns about the uneven distribution of garden spaces, necessitating queuing for access.

To delve deeper into this issue and analyze the spatial distribution of services within the TGCP, a comprehensive questionnaire survey targeting garden managers was conducted in 2020. The survey mainly investigated the opening time, days, frequency of use, and whether there are restrictions on the qualifications of cultivators. Additionally, this survey also incorporated official data on garden area sizes. Geographic Information System(GIS) was introduced to a comprehensive service assessment.

Furthermore, to solve the inequality of service distribution in the program, this study adopts advanced machine learning technology. This technique, known as K-nearest neighbors (KNN) clustering analysis. The application of KNN plays a vital role in identifying the service intensity of TGCP. The results reveal these services’ hot and cold spots, which provide valuable insights for the government to formulate the TGCP. It also promotes the strategic planning of the reasonable and equitable development of TGCP in the future.

ABSTRACT. Africa’s Sahel region is notorious for its harsh environmental conditions epitomized by recurrent droughts, flash floods, heat waves, rising temperatures and scanty and erratic rainfall. These harsh conditions have contributed to a scarcity in water resources necessitating sustainable water resources management involving all communities and stakeholders. This paper examines how community and stakeholder engagement in water resources management contributes towards water resources sustainability in the Sahel. Data for the study were collected through an in-depth review of literature. Findings reveal that, the main actors involved in water resources management in the Sahel are smallholder farmers and pastoralists; households; fishermen; local actors involved in tourism, environment and energy sectors; as well as experts (from NGOs and government institutions) in tourism, fisheries, environment, energy and the agricultural sectors. Although communities and local stakeholders are involved in water resources management in the Sahel, most of the decision and policy making is done by expert stakeholders from NGOs and government institutions. The limited involvement of communities and local stakeholders in the decision and policy making process regarding water resources management has led to recurrent conflicts which adversely affects water resources availability and sustainability in the Sahel. A better community-based and local stakeholder engagement in water resources management is critical to the attainment of water resources sustainability in Africa’s Sahel region.

ABSTRACT. Predicting and managing river flows is a necessity for flood control, low water levels, water supply, agriculture, and energy production. Knowing how to measure these flows is however a prerequisite. This constitutes hydrometry, a distinct and complementary science to hydrology and hydraulics (physics of flows). About a third of the rain that falls on the continents returns to the seas and oceans. On the scale of the Earth, nearly 36,000 km3 of water pass through rivers each year. But these quantities can be very unevenly distributed, both from one continent to another, and – for the same river – from one year to another or within the same year. This irregularity can only be approached by continuously measuring the flows of these rivers. However, the continuous measurement of the flows of a river cannot be obtained directly, but is the result of an experimental process combining several field observations...

ABSTRACT. Within the Lake Chad Basin, the unconfined Quaternary aquifer offers permanent and easy access to water resources. This transboundary regional aquifer is shared by Chad, Niger, Nigeria and Cameroon and extends over ~500,000 km2. Climatic conditions and repeated droughts as well as the intensification of agriculture in the region have multiple negative impacts on the aquifer such as changes in groundwater level and its quality. Being a strategic water resource for the whole Chadian region, the groundwater potential of the Quaternary aquifer must be better characterized and understood to evaluate its resilience to climate change and anthropogenic impact. In this study which is part of the IAEA technical project RAF7011 and RAF7019, stable isotopes and tritium of the water molecule were used to estimate water origin and residence time at the regional scale and to elucidate the interconnections between the different hydrological and hydrogeological components. Results show active recharge processes to the Quaternary aquifer as well as dynamic connections with surface waters (both river courses and wetlands) but also indicate less dynamic behavior of the Quaternary groundwater resource in some areas of the region. The Quaternary aquifer of the lake Chad basin can be considered as resilient in many zones of its extension, as interpretation of isotopic data indicates active recharge processes in several areas of the basin. Nevertheless, if the hydrogeological behavior of the Quaternary aquifer shows good connectivity, and sometimes a kind of dependence on river surface waters or to water stored in swamp areas, other sectors are less favorable to active recharge processes and show a clear tendency to inertial flow conditions and to long term storage of groundwater. Improving the available isotope hydrological information of the region can help secure knowledge of the actual situation and dynamics of hydrogeological processes. It can also provide important information and characteristics about the renewability of hydrogeological processes in an efficient, fast and economical way necessary for groundwater resources managers to ensure the long-term sustainability of this very important socio-economic resource for the whole Central African region.

ABSTRACT. Sustainable development of land use is determined by changes of the regional supply of Land Use Functions (LUFs) and the demand of future societal land use claims. LUFs are based on the ecosystem services concept, but more adapted to human land use. In this paper, we assessed 3 land-use scenarios towards sustainable development in south est tunisia in order to understand their impacts on LUFs and land use claims. For this, we extended an analytical framework designed to confront LUFs with land use claims identified in multi-level stakeholder strategies in a participatory manner.

ABSTRACT. Given the arid environmental conditions and unique physiographic setting of the eastern part of the UAE, the availability of fresh groundwater resources is limited. To address this, comprehensive water resource data was collected, meticulously reviewed, and validated before being incorporated into a GIS database. Subsequently, a localized Water Budget Model (WBM) based on GIS was developed to assess groundwater abstraction, recharge sources, and overall groundwater availability within the eastern region of the UAE, specifically in the Fujairah Emirate. The various sources contributing to groundwater recharge, including direct rainfall recharge, subsurface flow through mountain gaps, artificial recharge, and return flow, were examined. The data obtained from these analyses revealed that in both the eastern region and Fujairah Emirate, annual groundwater abstractions for irrigation stood at 240 and 133 million cubic meters (MCM), respectively, whereas the combined recharge rate from all sources amounted to 24 and 45 MCM per year. This indicates a stark imbalance, with groundwater abstraction exceeding the rate of natural renewal by over fivefold. Examining the WBM data for the years spanning from 1969 to 2019, it becomes evident that the freshwater resources in the eastern UAE are depleting. Substantial recharge occurred in water years 2019/2020 and 2021/2022. Moreover, the results from the water budget model underscore the influence of precipitation rate and pattern on both salinity levels and groundwater storage. Additionally, brackish groundwater resources are widespread in the region, with approximately 3 billion cubic meters (BCM) available, featuring salinity levels below 20,000 milligrams per liter (mg/l). Some farms are utilizing this brackish water after desalination. To identify potential zones for groundwater development, a simplified Analytical Hierarchy Analysis was conducted, considering factors such as soil type, groundwater potential, and groundwater quality.

ABSTRACT. Climate change is defined as large variations in climate averages that last for decades or more. Expert Team on Climate Change Detection and Indices (ETCCDI) are the sophisticated indices, developed to identify and monitor the regional and global climate change. Long-term trends in ETCCDI are needed to assess the impact on the environment of the Gurupura River basin located in the Dakshina Kannada District of Karnataka, India. The daily gridded datasets of Precipitation (0.250-E and 0.250-N), Minimum and Maximum Temperature (1.000-E and 1.000-N) from India Meteorological Department (IMD) are used to evaluate the 27 ETCCDI for the basin for 73 years (1950-2022). In order to maintain the spatial homogeneity, temperature datasets have been re-gridded from 1-degree to 0.25-degree using bilinear interpolation technique. The non-parametric Mann-Kendall (MK) test and Innovative Trend Analysis (ITA) is used to identify the trends associated with ETCCDI at 5% level of significance. Furthermore, Sen's slope estimator is used to determine the magnitude of the trends. The results indicated that extreme indices for both precipitation and temperature have shown significantly increase in trends, suggesting the study area is influenced largely due to climate change. Insignignicant increase in trends of total rainfall has been observed suggesting the annual water availability within the basin is unchanged, but the intensities have been fluctuating which may lead to catastrophic events. Furthermore, both maximum and minimum temperature based ETCCDI have shown significantly increase in trends, suggesting increased intensities of heat-waves and cold-waves respectively. The study concludes that the regional climate change may influence the fluctuations of meteorological variables over time, but it is not impacting on annual water availability. The policy makers may take necessitate initiatives on mitigating the future catastrophic events over the study region.

ABSTRACT. The necessity of integrated water resource management demands a detailed examination of river basin water inflows, exacerbated by population growth and climate change uncertainties causing heightened water stress and agricultural impacts. This study addresses the escalating challenges in river basin management arising from population growth and climate change-induced uncertainties, leading to heightened water stress and agricultural impacts. Focusing on the Souss basin in Morocco, the research pioneers the application of the ModSim decision support system, spanning the years 1990 to 2019. Utilizing recorded data on physical processes, hydraulic infrastructure, and management practices, ModSim successfully replicates deficit episodes across diverse irrigated perimeters. Notably, from 2012 to 2019, water supplies from various dams within the basin experience a significant decline ranging from 38% to 89%. The findings underscore an average unmet demand of 201 Mm3 for surface water from reservoirs in irrigated areas between 1990 and 2019, with a notable 55% increase in monthly demand during the dry season. The study reveals that compensatory withdrawals from groundwater resources address the substantial unmet demand, highlighting ModSim's effectiveness as a decision support tool for comprehending water resources planning challenges. Emphasizing the crucial role of such tools for water managers in understanding basin trade-offs, the research calls for further investigations to refine the representation of groundwater/surface water interactions, particularly in water-stressed regions like Souss, and provides a conceptual framework and detailed discussion for guiding efficient water management and governance.

ABSTRACT. Abstract Background: The Mediterranean region is highly susceptible to various climate and environmental risks, such as frequent flooding, severe droughts, and extreme rainfall occurrences. The interaction of large-scale atmospheric circulation with the atmosphere and ocean plays a vital role in regulating weather patterns, overall climate conditions, and activities within the region. A Saharan Oscillation Index (SaOI) has been developed as a climate index designed to capture the oscillation dynamics between the Saharan depression and the Azores High in the southern desert area. Objective: The objective of this study is to acquire a comprehensive understanding of the Saharan Oscillation Index (SaOI) and evaluate its relationship with the atmospheric circulation and other large-scale climate indices in the Mediterranean region. Methods: We calculated the time series of the SaOI index from 1950 to 2021 using its established formulation. To evaluate the relationship with the SaOI index, we computed its annual and seasonal correlations with multiple climate indices (NAOI, MOI, TNA, TSA, AMO, AO, El Niño, and WHP) using the Pearson correlation coefficient. Furthermore, we developed a linear regression model to quantify the strength of the relationship between these climate indices and SaOI. Results: Our analysis unveiled a moderate positive correlation between the Saharan Oscillation Index (SaOI) and the North Atlantic Oscillation Index (NAOI), Arctic Oscillation (AO), Océanic Nino index (ONI) and Western Hemisphere Warm Pool (WHP) indices, suggesting interconnected variability in the Mediterranean region. Additionally, we observed weak positive correlations between SaOI and several other climatic indices, namely the WHP, Tropical South Atlantic (TSA), Tropical North Atlantic (TNA), Mediterranean Oscillation Index (MOI), and El Niño. These findings imply a positive relationship and indicate potential influences among these variables. Conclusions: The correlation between the newly developed Saharan Oscillation Index (SaOI) and other prominent indices in the Mediterranean region provides an opportunity to explore potential relationships and interactions among these climatic phenomena. Investigating their correlations can yield valuable insights into their impact on both regional and global weather patterns. These teleconnections often arise from the propagation of atmospheric waves and the transfer of energy and momentum throughout the atmosphere.

ABSTRACT. The Southwest United States is a vast region characterized by diverse ecosystems, vibrant cultures, and productive economies. A set of interrelated environmental, economic, social, and technological factors, however, is causing increased stress and risk to water resilience and security. Stressors include climate change, a multi-decadal “megadrought” on the Colorado River, high agricultural water demand, rapid population growth and urbanization, aging infrastructure, and ineffective water policy. These stresses are leading to a range of impacts including significant reductions in surface water availability, groundwater depletion, intensified drought and aridification, and inequitable impacts on frontline communities and Indigenous Peoples. To address these risks and ensure a thriving future for the region will require boundary-spanning organizations that integrate scientific modeling and knowledge, technology development, policy reform, and participatory and equitable approaches to decision making.

One example of this integrated approach is the Arizona Water Innovation Initiative (AWII). The AWII is use-inspired, transdisciplinary research, development, and solutions project led by Arizona State University (ASU). Through this initiative, ASU works with diverse academic, industrial, municipal, agricultural, tribal and international partners to rapidly accelerate and deploy new approaches and technology for water conservation, augmentation, desalination, efficiency, infrastructure and reuse. The AWII leverages, expands, and integrates the work of ASU and its partners throughout Arizona and across the Southwest United States, and scales those advancements to implement evidence-based solutions. The initiative is implemented through five integrated project areas focused on innovations in water engineering and technology, advanced modeling and decision support, water policy, public engagement, and water security.

This paper, which contributes to the Water Resources Sustainability conference theme, provides an overview of the Arizona Water Innovation Initiative including key scientific findings, modeling advances, engineering and technology developments, public engagement efforts, and policy recommendations. For example, AWII has co-developed technology roadmaps, testbeds, policy guidance, and public engagement for water conservation, atmospheric water capture, advanced water purification, and industrial wastewater recycling to improve water efficiencies for advanced manufacturing and micro-electronics. By combining climate and hydrological models and Earth-observing satellite products with dynamic visualization and user interface/user experience design, the AWII is producing an advanced water observatory and decision support system to improve water operations. To enhance public understanding and engagement in water decision-making the AWII is using new approaches such as virtual and augmented reality, gameplay, and AI-enabled chatbots to deliver engaging and credible and content. Meanwhile, AWII is supporting participatory water decision-making, integrated engineered-social infrastructure interventions, and improved measurement and monitoring of household and individual water insecurity.

While the AWII is focused on the water challenges and solutions for the State of Arizona in the Southwest United States, the lessons and approaches are transferable to other semiarid and water scarce regions. Through international scientific and policy collaboration, the AWII seeks to promote sustainable development to drive a thriving water future for all.

ABSTRACT. Limited water resources in the semi-arid region result from unpredictable rainfall patterns and elevated temperatures leading to high evaporation rates. It is important to ensure the sustainability of these resources to satisfy ecological and human needs. From the literature and field examinations, the Western approach to procuring water for inhabitants in the semi-arid region of Africa has resulted in mixed outcomes. Increasing population and climate change are exacerbating the procurement of water in the region of Chad Basin in West Africa. Lake Chad recharges its groundwater at least in the western basin, although its apparent haphazard exploitation needs serious attention. Water resource management practices, which include the damming of the Chari and Logone Rivers in Cameroon, have been of concern to neighboring States. The World Health Organization (WHO) recommends one hundred liters of water per person per day and a minimum of twenty-five liters of fresh water for basic hygiene. Are these recommendations realistic for the semi-arid regions in Africa? Should we redefine these statistics as being dependent on various regions of the world, the average age of the population, land use and industrial activities? An examination from personal experience suggests that people in semi-arid regions in Africa could live on less (~ten liters) water per person per day. There is also the challenge of stakeholder engagement. For instance, not all stakeholders participate in water resource management in the Chad Basin when boreholes are drilled, and the water is used for husbandry. However, the water from those boreholes can sometimes be too hot (40-60°C) for the animals to drink. Due to the high-water temperature, especially in afternoons, the boreholes under artesian conditions are usually allowed to free flow without capping to allow the water to cool off, but this leads to water loss through evaporation. The amount of surface water available can be unpredictable as it is affected by the rainfall variation (between 1000 mm in the south to 100 mm annual precipitation in the north). Climate change has a significant effect on the water quantity and quality as it can be shown that El Nino southern oscillation and Atlantic multidecadal oscillations all appear to affect the Lake Chad water level and quality. The El Nino, along with anthropogenic activities, including unrests and wars affect both the quantity and quality of the water resources in Lake Chad Basin. Efforts should be geared toward minimizing unrest and wars, involving stakeholders in water resources management, and mitigating the effects of climate change in this region.

ABSTRACT. Tropical Dry Forests (TDFs) are considered water-limited ecosystems, located in arid and semi-arid regions globally, and are typified by a minimum of a 3-month dry season with less than 100 mm of rainfall. TDFs are also an increasingly endangered biome, with high rates of deforestation and degradation owing to increasing populations and the conversion of forests into agriculture and urban areas. This combination of factors leads to an increase in water stress in dry regions, which is likely exacerbated by climate change. Currently, there is little research on the combined effects of population change, socioeconomic development, and shifting climatic regimes on water shortages and stress at the subnational level in tropical dry forest regions. Therefore, the objective of this study was to assess the baseline changes in water shortage and stress over the past two decades and to use these trends to project the sub-national water shortage and stress under different climatic scenarios. This information can be used to assess and plan future management and water-sharing strategies between water-scarce and water-rich areas within countries and in transboundary agreements.

Data were obtained from a combination of open-source databases, including high-resolution population density data from the Humanitarian Data Exchange, vital statistics, water demand by industry and domestic uses from the World Bank, annual land cover change data from the European Space Agency Climate Change Initiative, and climate change projections from the CMIP6 model outputs. Urban and agricultural expansions were projected based on historical rates of change using a Bayesian probability cellular automata model. Trends in vital statistics were projected to project future populations, which were then statistically downscaled using HDX population density maps and future urban area projections. One caveat is that it does not include the migration of people and only looks at vital statistics within the country. The change in per capita domestic and industrial water demand was projected using the MARS model. This model is useful because it is a linear piecewise model that accounts for rapid increases in water demand as well as the plateauing of water demand. Surface water availability was modelled using the change in rainfall projected in the CMIP models. Water stress and shortage were then calculated at the sub-watershed level.

Overall, we found that decrease in water resources and increases in per capita demand increased water stress and shortages in Peru (p=0.003), Columbia (p = 0.019), and Indonesia (p=0.002), respectively. In contrast, projections of increased rainfall may alleviate some of the water stress in the Caribbean. Overall, these data can provide a baseline to help decision makers plan both infrastructure and water management plans to work towards climate change adaptation and ensure that sufficient water is available for residents in the region.

ABSTRACT. The Nile, a colossal river spanning nearly 6700 kilometers from its distant origins in Burundi and Rwanda's Kagera River to Egypt's Delta, stands as one of Earth's magnificent waterways. Its vast basin, covering about 2.9 million square kilometers, amounts to roughly a tenth of Africa's land. Within this expanse, 336 million people, out of Africa's 850 million population, call home. The basin's population has surged, poised to double from 1995 to 2025, underlining the challenge of escalating demands on resources. The Nile's hydrographic boundaries define its extremes – the Ruwenzori Range's peak at around 5120 meters above mean sea level and El-Quattara depression's trough descending to about 160 meters below mean sea level. Climate across Africa exhibits an array of patterns, from equatorial humidity to Mediterranean dryness, encompassing various temporal and spatial shifts. Sub-regional scales are exposed to erratic events like floods and droughts, magnified by swelling populations and dwindling resources. The Nile Basin's climate is categorized into three types: Mediterranean along the coast to just south of Cairo, Sahara desert from there to Atbara, and tropical encompassing the area south of Atbara. Climate change's potential repercussions, often overshadowed by population growth, have been addressed less, despite prior research indicating the basin's vulnerability. In the Nile Basin, climate change could compound water scarcity issues. Shifts in precipitation over Ethiopian hills (supplying 85% of Nile flow) and equatorial lakes (15%), and rising temperatures, might escalate water loss due to evaporation and surging demands. Altered precipitation patterns might lead to coastal water losses without proper catchment management. Escalating airborne dust, soil salinity, and domestic usage could degrade water quality, while rising sea levels might introduce saline intrusion in coastal zones, tainting groundwater. Groundwater resources, crucial for areas plagued by drought, might dwindle due to reduced precipitation. Information on regional groundwater is scant, despite its significance to livelihoods and ecosystems. Evaluating climate change impacts on the Nile, a macro-hydrology model powered by temperature and precipitation data from 11 General Circulation Models (GCMs) and two emissions scenarios (A2 and B1), illustrates potential outcomes. This study explores climate change's hydrological impact on the Nile's water resources by dissecting crucial drivers from data archives. By examining hydropower production and irrigation water releases at the High Aswan Dam, an assessment of climate change implications on Nile water resources emerges. Early-century increases in production and releases of 112-118% give way to decreases of 87-97% in later periods, under different emissions scenarios. This underscores the complex interplay between climate shifts and water resource management in the Nile Basin.

ABSTRACT. Field experiments were carried out during 2018 and 2019 at Raichur (16º 12' N, 77º 20' E; elevation, 389 m) Karnataka, India. During Kharif paddy was grown in transplanting rice (TPR) and direct seeded rice (DSR) establishments. The DSR paddy was sown using tractor drawn seed drill in July and harvested during December. Treatments consists of TPR and DSR in rainy season and rice followed by chickpea, mustard, ricebean, cowpea, greengram, sorghum field bean compared with rice-rice system. For TPR 25 days old seedlings were transplanted on first week of September. Regional recommended production practices of the paddy were followed for both the methods. After kharif paddy harvest the land was prepared by using tractor drawn cultivator twice and rotavator to brought soil fine tilth. Crops in paddy fallows were sown on December/January at both the locations. Plant-mediated CH4, N2O and CO2 emission flux from the experimental plots was measured by closed chamber (0.5 x 0.3 x 1.0 m) method at regular intervals upto harvest. Results showed that grain and straw yield of TPR was higher (5.53 %) than DSR at both the locations. Whereas DSR was matures 10 days earlier to TPR. Yield attributes were not significantly differed between the establishment methods. Whereas, net economic returns and benefit cost (B:C) ratio were higher with DSR as compared to TPR. It was mainly due to relatively lower cost of cultivation in DSR. Greenhouse gas emission (GHG) in terms of CO2, CH4 and N2O were significantly higher in TPR over DSR. Across the crops in rabi season, drip irrigation saved 8.3 to 40.8 % water and 14.5 % yield over surface irrigation. Whereas number of irrigations were also higher in drip irrigation as compared to surface irrigation. Duration of the crop and water requirement differences may responsible for varied water application. Market prices of rabi crops and rice was converted into rice equivalent yield (REY). Results showed there was no significant difference between TPR (3827 kg ha-1) and DSR (3832 kg ha-1). Whereas total REY was sum of rainy season rice yield and rabi REY indicated higher TPR over DSR. For rabi crops, irrigation water applied through drip has recorded higher average grain yield (1246 kg ha-1) as compared to surface irrigation (984 kg ha-1) across the crops grown in paddy fallows. Across the crops in rabi, total REY was significantly higher in rice-cowpea and rice-lablab sequence as compared to other cropping sequence. Rabi crops grown in paddy fallows under drip irrigation and surface irrigation was also influence on economic returns over existing rice-rice system. Significantly higher net return and B:C was obtained from rice followed by cowpea/ricebean/sorghum/lablab system over rice-rice. These crops grown in Kharif DSR also showed similar results with respect to net returns and B:C ratio. Drip irrigation for crops in paddy fallows gave higher economics. Results of the study summarizes DSR paddy in rainy season and cowpea and lablab were found potential crops to sustain soil health and drip irrigation can enhance water use efficiency.

ABSTRACT. Groundwater extraction in the desert lands of Egypt has increased significantly since the mid-twentieth century, particularly in the Western Desert between the Nile River and the Libyan border, where the world's largest aquifer, the Nubian Sandstone Aquifer, is located. Egypt has initiated multiple groundwater development projects since 1958, starting with the New Valley Project, to increase agricultural production and create employment in rural areas. Groundwater extraction has increased significantly since the 1990s due to the economic liberalization where the Western Desert became an interest for the government and Egyptian companies and Arab states to supplement the Nile basin to achieve food security. This paper documents changes in water quality and drainage issues in Kharga Oasis, Egypt using remote sensing analysis and ground truth data. Landsat images from the 1980s to 2022 were analyzed using vegetation and moisture indices to quantify changes in cultivated lands over time. Field visits helped to understand groundwater usage patterns. Socioeconomic data linked agricultural expansion to development programs. Remote sensing satellite image analysis found a major expansion of cultivated lands, especially since the 1990s. This corresponds to increased groundwater extraction observed in the well data. The proliferation of drainage ponds was documented through the remote sensing images where there is a clear correlation between the drainage ponds and increased moisture content of soils, indicating issues with salinity accumulation due to over-irrigation. Moreover, the groundwater analysis shows declining water quality over time, with increasing salinity and pollution levels. This matches the spatial pattern of drainage ponds observed. The overall study demonstrates how agricultural development has led to salinity and drainage issues. The remote sensing and ground data provide spatial and temporal evidence of how water quality has declined in parallel with the expansion of irrigated agriculture reliant on unsustainable groundwater extraction.

ABSTRACT. The stakeholders’ forum aimed to enhance the capacities of policymakers, managers, and practitioners of river basin organizations on flood management through knowledge sharing of new approaches, techniques, methodologies, and good practices from partners here and abroad to help achieve effective implementation of integrated flood risk management as a component of integrated water resources management. The study followed a qualitative research methodology; thus, observation and documentation of each series of planned activities, semi-structured and unstructured interviews with the executive leaders of national agencies and international partners, and discourse analysis of the shared presentations and knowledge exchange between or among the stakeholders were conducted to surface specific themes that described how this stakeholders’ forum enhanced the implementation of integrated water resources management in the country through multipartite communication platform. The research findings revealed that international and national partnership is fortified and R&D efforts will be rapidly realized though a multipartite information exchange, collaborative workshop, technology transfer, and other knowledge-sharing activities. Moreover, legal agreements entered by all stakeholders to scale up global and community linkages is a salient measure to encourage and motivate stakeholders to take part in the implementation of STI-based efforts stipulated in such legal document. Joint field visits, series of fellowship, and use of websites for information dissemination also have pivotal roles in acquiring a profound understanding of dam situations in the Philippines and Japan, and how integrated water resources management will be communicated to various community partners. Thus, the forum served as a channel that bridged what the government agencies and organizations know about flood and sedimentation management and what the community partners need to understand to revitalize science-community-government-academe collaboration.

ABSTRACT. Water resources can be considered to be a key component to the livelihoods of economies. This is due to the fact that water enters the production processes of almost all sectors of an economy, most notably agriculture, energy and manufacturing. The need to understand and analyse the interconnections between water resources and the economy is heightened considering the increased demand for water due to population and economic growth, and the reduced availability of water as a consequence of climate change.

The complex relationship between water and the economy has been widely analysed using economy-wide models like Computable General Equilibrium models (CGE) as a tool to examine the direct and indirect effects of potential changes in water resources, for finding the optimal technique for water pricing and for examining the economic responses to the introduction of new water policies. Typically, water extended CGE models are expected to encompass the entire water system of an economy and models how the economy reacts to changes in the water system. However, the literature shows variations in the way water is incorporated into CGE models due to the multifaceted nature of water uses and sources across sectors in an economy. Indeed, the literature demonstrates that the majority of water-CGE models are focused on the agricultural sector and very few models tackle non-agricultural sectors and their water consumption.

This paper is interested in analysing the methodological issues of incorporating water resources into CGE models by comprehensively reviewing the existing applications of water extended CGE models. The literature suggests that there are three main issues to incorporating water into CGEs. First is the lack of water data availability providing a detailed sectoral water usage by source/type of water and its competing uses across sectors. Second, the issue of the “direct” or “indirect” representation of water resources in the model. The third issue is finding an appropriate price for water in the absence of a well-functioning water market.

The findings of this systematic review identifies how existing water-CGE modelers built their model, including the sources of water use data, how water was represented in their model and what was the water price estimation technique. These findings should aid modelers interested in analysing the role of water in an economy using CGE models in building their water-CGE model.

ABSTRACT. Due to Jordan's paucity of natural resources, there are various environmental challenges that make it difficult to maintain population increase. It is anticipated that Jordan, one of the nations with the fewest natural resources, would slip below the poverty line. This study addresses the most pressing environmental concerns confronting Jordan, including water constraint, pollution, and desertification. The topic of water shortage is then discussed, along with the environmental repercussions of current practices and proposals for improvement. This study describes a "sustainability package" that may help avert these problems and establish a sustainable future. Governmental and non-government organizations are closely engaged in environmental concerns to build a solid foundation for environmental protection. Citizens and entities should collaborate to discover realistic answers to the nation's concerns. The primary goal of this research is to establish a framework for environmental water preservation in Jordan, ensuring that water resources are managed and utilized in a sustainable, egalitarian, and health-protective manner. This includes balancing the demands of various water users, safeguarding water quality, and preserving water supplies for future generations. It is feasible to encourage water conservation, enhance water management practices, and safeguard water resources for future generations by establishing such a framework for environmental water preservation in Jordan. This may help guarantee that there is enough water to fulfil people's and the environment's requirements, and that aquatic ecosystems stay healthy and resilient in the face of increasing demands from human activities.

ABSTRACT. Groundwater resources provide a myriad of economic benefits to businesses, consumers and society at large, from supporting agricultural holdings in the cultivation of crops to ensure food security, to the provision of clean water to households and tourists alike. Nonetheless, despite these evident benefits across a wide spectrum of uses, there are significant lacunae in the valuation of groundwater as an economic resource especially so from a policy perspective. The dire state of affairs in terms of applied environmental valuation is probably the result of two polarizing intellectual forces: on one hand the difficulty in the accurate estimation of non-market benefits has fueled a reluctance to approach this subject in policy circles – so much so that some new economic models shun it completely. On the other hand, the old adage of “what gets measured, gets valued” might be very relevant in this case, especially since while attention has frequently been drawn to negative externalities through the polluter pays principle, less attention has been devoted to positive externalities that emanate directly (or indirectly) from the supply of groundwater.

Against this backdrop, this paper seeks to develop a tractable approach for the valuation of groundwater resources across their various uses in Malta, a small island EU member state. Malta provides a compelling context for the undertaking of such an analysis. As a small island state in the middle of the Mediterranean with a semi-arid climate and a fast-growing population, Malta’s natural water supplies are not sufficient, even if used sustainably. However this has also spurred innovation and forward thinking aimed at managing and conserving such resources.

The focus of this research is on the private use of groundwater across two broad market segments, namely agriculture and industry, given that these constitute the two main private abstractors of groundwater in Malta (beyond government for public water supply). This study aims at developing a framework for the identification, characterization and – where possible – the quantification of social demand for groundwater. This framework follows the social demand model in mainstream economics that captures both private financial benefits resulting from each sector’s use of these resources (e.g., enhanced agricultural productivity) as well as the external benefits emanating from water use (e.g., recreational value and food security, wider employment creation). These values shall be estimated utilizing a variety of academically recognized approaches ranging from productivity and market-based methods to values derived from general-equilibrium based input-output models which identify the economic impact (spill-over effects) of groundwater use across these sectors. The benefit-transfer method –notwithstanding its limitations- shall also be considered as an option. We shall then utilize these results to highlight the need for the valuation of such resources, with a number of policy recommendations as well as suggestions for future research in this area. The model/framework’s inherent flexibility means that it can be applied to other countries with reasonable adjustments.

ABSTRACT. The UAE and Oman have important coastal ecoregions along the Sea of Oman habitat to a flourishing economy, natural resources, wildlife, and fishery. Extensive human intervention in the last decades through intense use of fertilizers, pesticides, uncontrolled management of water resources and contamination of the sea, make the region highly fragile to climate change. The coastal region of the Sea of Oman is commonly exposed to tropical cyclones, torrential rainfall and tsunami waves making this coastal strip sensitive to climate change and sea level rise induced by global warming. A prospect for suggested research and action plans is given herein which target cooperation and coordination between the UAE University and Sultan Qaboos University in transboundary and interdisciplinary investigations. The collaboration aims to assess the effects of anthropogenic and natural changes in the Sea of Oman region in both countries accurately. Investigation projects will be based on experts’ cooperation in many fields of science and technology such as geosciences, biology, chemistry, environment, geography, marine sciences, to ensure delivering plans to reduce the ongoing environmental threats and secure a better prospect for the region. In addition, the proposed project aims at establishing innovative research in the field of climate change for better resilience and mitigation regarding the impacts of climate change. The transboundary and interdisciplinary research partnerships between Sultan Qaboos University and the United Arab Emirates University targets the evaluation of climate change consequences on the region (land and sea) including effects of drought, tropical cyclones, torrential rainfall, and vulnerability to sea level rise and saltwater intrusion. Moreover, the research aims to identify the ongoing risks to the shallow marine environment and the interaction between land and sea using data of anthropogenic and natural contaminants such as seepage of water from land to sea, seawater intrusion inland and dust input.

ABSTRACT. In constructal design (Bejan and Lorente, 2013) one (Nature or engineer) optimizes an integral quantity (in our case, the pore water storage) of a dynamic system (saturated-unsaturated flow obeying the Darcy law) by controlling a set of variables (e.g. the shape of a water-harvesting entity and hydraulic properties of the components of the main (top) soil or porous liner, which impedes percolation, as well as the capillary rise of water-soluble salts into the topsoil). Our “constructal” approach is based on the design of a system of capillary barriers that retain irrigation water in topsoil and protect it from secondary salinization. Capillary barriers can be 1,2, and 3-D architectures, depending on the directions of capillarity blocking, vegetation placement (solid cover, local plantings) and types of irrigation (e.g. sprinkling, flooding, furrow irrigation, jet, or drip) (Al-Maktoumi et al., 2014, Smagin, 2012, Smagin et al., 2005, 2015, 2021). Barriers’ physical parameters, including doses and optimal depth of application of soil conditioners, options for application to the soil (in a separate layer or mixing), methods and modes of irrigation of individual crops, are determined using technological design, involving modern computer models of energy and mass transfer in the system “soil-plant-atmosphere”, such as HYDRUS-1D or HYDRUS-2/3D (Šimunek et al., 2006). An example of such modeling is presented for a tilted turf layer which confines a conical zone similar to one studied analytically (Kacimov, 2008) as a water-harvesting entity. Complex field testing of “constructozems” (smartly designed and constructed soil composites) with capillary barriers in experiments with lawn, woody vegetation and vegetable crops with soil and environmental monitoring of their functionality (weather conditions, accounting for precipitation, evaporation, irrigation, unproductive groundwater runoff, temperature, water-air, salt regimes and biological activity (respiration) of soil, biomass, etc.). plant yields) confirmed the high efficiency of innovative technological developments. They increase productivity from 30-50% (vegetable crops) to 50-100% or more (lawn grasses, tree crops) with 100% survival rate of plantings, 1.3-2 fold saving of irrigation moisture and reliable protection of the root layer from secondary salinization, and in the case of innovative gel-forming soil conditioners with biocides, additional protection from pathogenic diseases, including late blight.

ABSTRACT. Integrated circular approach (reduce, reuse, recycle) can be used in water deficit countries for sustainable production of food in urban agriculture using hydroponic and aquaponics systems. Hydroponic system with fish and vegetable production (aquaponics system) using treated wastewater will contribute to Sustainable Consumption and Production (SCP) in the region. Therefore, the aim of the study was to evaluate the effect of treated wastewater (TWW) on plant growth and production using hydroponic and aquaponics systems. In addition, the approach will enhance the saving of freshwater and used fertilizer in similar agriculture systems. Leafy vegetable (lettuce) was planted in two groups, the first group using tertiary TWW and the other using freshwater. Plants chlorophyll content, heights and weights were continuously monitored and recorded. Water samples used in both systems were analyzed and compared with the international standards. Both plants and water samples were tested for metal contents using ICP machine. Treated wastewater application had a positive effect on plant growth and all measured parameters. Moreover, concentration of metals in plant samples were within the international standards. In aquaponics system, nine tanks with dimensions of 80*40*40 cm were filled either with freshwater or a mixture of freshwater and treated waste water at a ratio of 50:50 and 75:25 %. Tilapia fish was added to each tank (25 pieces/tank) with initial body weight of 49 g. Each tank was connected with another tank of same dimensions that was used to grow lettuce and bean crops on the top layer. Water was circulating between two tanks. However, no fertilizer was added to all treatments and all tanks got similar amount of fish feed. Tanks with treated wastewater got higher values of metal content due to metals added from treated wastewater compared to freshwater alone. Therefore, lettuce and bean growth was much better and got higher values of chlorophyll content compared to control tanks. All waters got similar values of heavy metals with the small increase in some elements found in treated wastewater. Whereas, the edible part of lettuce grown in treated wastewater got higher value of Ba and Fe compared to control. Similar concentrations were found with bean plants with higher values in treated wastewater compared to freshwater. However, the concentrations of heavy metals in the edible parts of all treatments were low and within the international standards. Fish analyses showed that all tested heavy metals were within the safe limit. However, applying this technique in the farming system will help the environment by utilizing treated wastewater and reducing fertilizer applications. Moreover, farmer income will increase since both crops and fish will be produced with minimum resources and high quality.

ABSTRACT. Seawater intrusion (SWI) in coastal aquifers significantly degrades the groundwater quality. Consequently, remedial strategies need to be conducted, developed, and planned with high efficiency. While several studies have investigated various aspects of SWI using numerical models, physical sandbox experiments (or combinations of both) have not explored the dynamics of SWI under aquifer storage and recovery (ASR) practice in unconfined aquifers where the well screens are placed at various depths and injection-abstraction (IA) periods and intensities are major control variables. The aim of this study is to investigate the dynamics of saline water interface, water table of fresh water, and topology of motion of pore waters of two contrasting densities under various runs of ASR systems in both homogeneous and layered unconfined coastal aquifer settings. A plexiglas sandbox physical model is used to represent the unconfined homogenous and heterogeneous coastal aquifers made of artificial white sands. Various scenarios were explored: different injection depths, different storage periods, and various rates of abstraction. In the layered aquifer, we explored IA from either the upper or lower layer. We used both qualitative (colored images) and quantitative (groundwater level and salinity, measured in the laboratory with the help of special mini-piezometers) descriptors. The results illustrate the impact of the ASR system in better sustaining the water supply from the coastal aquifers. ASR is found to allow more groundwater abstraction from the aquifer without jeopardizing the water quality. Better planning and optimization (by variation of the loci of IA wells’ screens and hydraulic regimes of operation) of ASR will help to sustain the aquifer’s groundwater quality and hence the supply. The study helps to better understand the potential dynamics of groundwater under the ASR system in a layered system, as in the case of Al-Batinah North coastal aquifer (Oman), where major abstraction is from the more conductive upper layer. We proved that a negative perception of some coastal ASR projects comes from their poor initial design, inadequate construction (very far from the optimum), and flimsy management/operation, which do not mitigate but rather exacerbate SWI. Our findings help validate numerical tools (also developed for geometrical, hydraulic, and IA parameters used in the experiments) and represent a new benchmarking case study for those codes. This is important due to the complicated flow patterns of density-dependent flow and transport in a layered heterogeneous aquifer setting.

ABSTRACT. In a sand tank experiment, flow rates are measured through a bottom outlet through which pore water seeps into a valved pipe. Total piezometric heads are measured on the left and right of the outlet. Analytically, the tank outlet is modeled as Zhukovsky’s drains, which have a constant pressure head. This flow rates depend on the pipe's elevation and length, which are experimentally varied. To simulate Darcian flows in the tank, we used HYDRUS2D and compared experimental observations with analytical and numerical modeling. We found the flow rate in a tank with impermeable lateral boundaries is nearly the same as that of for the case of constant head boundaries. Analytical 2D solutions (derived from Polubarinova-Kochina conformal mappings for seepage under concrete dams) give almost the same flow rate as HYDRUS2D models for finite-sized sand tanks. A commingled seepage in the sand tank and flow of water through a pipe system is analyzed with the help of calculated losses of Darcian heads and static pressure heads in 1-D pipe flows, in which Darcy-Weisbach's friction factors for hydraulic resistors are used.

ABSTRACT. Preferential flow of water, infiltrated after irrigation events or rainfalls, is governed by quasi-vertical “fingers” packed with a highly permeable porous material, which extend into an ambient, relatively low permeable soil (Schaetzl and Thompson, 2015). In our study, we model a single “finger” of a width dimensions of width 'a' and depth 'b', filled with a material exhibiting a hydraulic conductivity of kf. A shallow water table is at a depth c where c>b. The ambient soil has a hydraulic conductivity ks, which is significantly less than kf. In our analytical model, we investigate the steady seepage from a horizontal soil surface and the boundary of the finger, which are considered as lines of constant piezometric head. The flow domain is a soil pentagon, which is conformally mapped onto a strip in the complex potential plain (Kacimov and Al-Ismaily, 2023; Strack, 2017). The flow net, isobars, isochrones and other kinematic characteristics of Darcian seepage are obtained. The presented numerical models involve both the ambient soil and finger’s filling. We solved the Richards-Richardson within a saturated-unsaturated half-strip, treating it as a flow domain. This is done under diverse initial and boundary conditions presented at the apex of this half-strip. Analogously, an axisymmetric flow is modeled with a cylindrical “finger” with a highly permeable filling. The wetting front, groundwater mound dynamics and eventual waterlogging under the axes of the fingers are evaluated. Transport of solutes from the soil surface to the water table is also modeled in HYDRUS equation (Radcliffe and Šimůnek, 2010). Both analytical and numerical results are compared with the trivial case of seepage and transport in a homogeneous soil layer with a thickness of c. The obtained solutions are mathematically similar to ones for MAR through the so-called “dry wells” drilled into a vadose zone of an unconfined aquifer to be replenished. The hydropedology - groundwater hydrology nexus is discussed. Kacimov, A. and Al-Ismaily, S. (2023). Indented interfaces between soil horizons: Analytical and HYDRUS2D modeling of 2-D seepage towards a wedge. Eurasian Soil Science, DOI: 10.1134/S1064229323600707. Radcliffe, D. , J. Šimůnek, J. (2010). Soil Physics with HYDRUS: Modeling and Applications. CRC Press, Boca Raton. Schaetzl, R.J. , Thompson, M.L. (2015). Soils: Genesis and Geomorphology. Cambridge Univ. Press. Strack, O.D. (2017). Analytical Groundwater Mechanics. Cambridge Univ. Press.

ABSTRACT. Global warming and climate change are impacting the social environment detrimentally and are increasing the death toll due to more severe natural disasters worldwide. For example, droughts in California, USA, caused economic losses amounting to US $2.2 billion and $3 billion in 2014 and 2015, respectively, and drought that occurred in India from 2000-2002 caused the deaths of 20 people and economic losses of US $1.5 billion. Besides, global arid regions are expected to increase ~10% by 2100 under a high-emission scenario. The more arid background brings up the more frequent occurrence of severer, longer, and areally extensive droughts that are likely to lead to water scarcity. Central northeast and west central India showed an increasing trend of the percentage (%) of the area under drought in the past (1950-2010), and % of the area under “above moderate drought” across India is expected to increase up to 70% by 2095 under Representative Concentration Pathway (RCP) 8.5 scenario. Warming global temperature is also affecting the change in the location of deep convection over oceans and, in turn, the southwest monsoon rainfall, which contributes to 70-90% of the annual rainfall in India, tending to be dormant due to the amplified El Nino-Southern Oscillation (ENSO) and the stronger equatorial Indian Ocean positive anomalies. More frequent occurrence of Rossby waves, which stagnate atmospheric flow, and the intensified land-atmospheric feedback under warming climate make an already initiated drought more severe, longer, and spatially more extensive. Since drought occurs naturally in hydrologic processes, its occurrences are beyond human control. Thus, what humans can do is to be prepared for the anticipated droughts to mitigate drought impacts. To reduce relief losses and mitigate drought impacts, a proactive drought management plan needs to be prepared, based on accurate drought early warning, forecasting, and risk analysis. Application of deep learning, such as long short-term memory (LSTM) networks, and entropy spectral analysis extended forecast lead time with higher accuracy insurmountable with traditional statistical or machine learning models and have shown their applicability for proactive mitigation planning based on risk analysis. However, more improved monitoring systems for drought indicators, drought indices, which can consider implications of human activities and hydrologic processes explicitly, and more accurate drought forecasting is required to be prepared for severe droughts. Besides, historical drought impact data should be archived and organized for reliable assessment of vulnerability and risk to drought. Therefore, this study discusses the impacts of drought in the past and future and causal mechanisms based on drought events in India and suggests ways to be prepared for the expected more severe droughts from the technical and governmental machinery perspectives.

ABSTRACT. The results of analysis of extreme inflow are used for design of dams, bridges, culverts and flood control structures. In this study, analysis of annual maximum discharge (AMD) into the large reservoir was carried out using Modified Mann-Kandall test, Innovative Trend Analysis and generalized extreme value type I distribution. The data of annual extreme inflow into the Ukai dam, India for Pre-dam (1939-1972) and Post-dam (1973-2022) were used in this analysis. There is no trend detected in the Post dam scenario while increasing trend is detected in the Pre dam scenario for the annual maximum inflow. The generalized extreme value type I distribution indicated that the extreme inflow values for the given return period decreases in the post-dam scenarios compared to pre-dam scenarios. The 100-year return period is computed to be 34147 m3/s for the Post-dam scenario. The comparison of the Pre- and Post- dam scenario indicated that the spillway gates of the Ukai dam are sufficient to discharge the flood corresponding the 730-year return period into the Ukai dam. The study presented in this paper can be repeated every decade with updated long data record to understand the changes in the extreme inflows in the changing climate.

ABSTRACT. The lack of adequate understanding of flood risk by citizens (e.g., exposure of homes to flooding) and as a whole community (e.g., closures of businesses, schools and hospitals) contributes to lack of participation in flood mitigation efforts as individuals and as community. The current study aims at understanding knowledge gaps that flood-prone groups may have about the primary reasons of flooding in their communities, the socio-economic impacts of flooding, and the viable options for flood mitigation solutions that they should pursue under current and future climate conditions. The study also aims at investigating how hydroinformatic technologies (e.g., high-resolution hydrologic and hydraulic modeling, interactive geospatial visualizations), along with community-specific socioeconomic analysis, can support decision making on flood risk and mitigation. The area of interest in this study is a flood-prone region in the Lafayette Parish located in southern Louisiana, USA. This region is highly affected by compound flooding from riverine and coastal sources due to its geographic location and proximity to the Gulf of Mexico. To investigate these questions, the study conducted a set of focus groups and workshops with a total of 80 participants from the community that represented different types of stakeholders with different roles in flood risk mitigation including city and parish officials, community developers, engineering and planning firms, news organizations, and citizens from diverse neighborhoods with different socio-economic backgrounds. To provide the workshops participants with authentic environments and allow them to share authentic feedback, the study developed a set of hydroinformatic tools that are based on hydrodynamic model simulations covering the entire parish. The tools included web-based applications that (a) quantify economic damages to individual structures such as houses and businesses as examples of individual-level impacts (https://ourfloodrisk.org/tools/structure-damage-tool/), and (b) quantify impacts on road drivability and the ability to access critical infrastructures and evacuation points as examples of community-scale impacts (https://ourfloodrisk.org/tools/community-flood-impacts-tool/). During the workshops, participants were also presented with aggregated socio-economic flood risk impacts at community-wide scales. The study results showed that communities need flood hydroinformatic informational tools and technologies that allow individuals to understand their personal flood risk, yet broaden such understanding to community-wide impacts and the connectivity of flood risk to overriding climatic extremes and socio-economic drivers. The results show the need for tools that provide actionable information and support flood mitigation decisions by individuals and the full community, thus increasing the flood resilience of the overall community via improving engagement in flood mitigation efforts and formulation of sound and inclusive public policies.

ABSTRACT. Irrigation plays a fundamental role in mitigating food production challenges in drought-prone regions. The performance of such systems, especially large-scale ones, remains an open research area particularly in developing countries due to data scarcity. This study presents an assessment of the performance of large irrigation systems by comparing farmers’ perception based on questionnaires and a newly developed remote sensing-based drought index for four gravity irrigated schemes across Sudan. A survey of 287 farmers was conducted from 2016-2022. Occurrence of decreasing rainfall and increasing daytime temperature in the growing season was reported by 53.7% and 67.9% of the respondents, respectively. Around 81% of the farmers perceived these climatic changes during the last 5 to 15 years. The survey showed that the majority of the farmers (76.7%) cultivate sorghum, followed by sesame (24.7%), sunflower (7.0%), cotton (1.4%) and other crops (32.8%). Similar to the national agricultural statistics, the survey identified sorghum as the main staple food crop. More than 50% of the interviewees perceived sorghum as the crop mostly affected by declining yield. They attributed this decline mainly to poor soil fertility and decreasing rainfall amounts, respectively reported by 61.7% and 50.5% of the farmers. Accordingly, we examined the drought conditions and risk to sorghum yield for each of the four schemes during the period 2001-2020. A drought index was derived based on: 1) an annual land-use classification product, 2) national sorghum statistics, and 3) normalized difference vegetation index (NDVI) to calculate integrated NDVI (iNDVI) over the growing season (June-October) as a proxy for productivity. By scaling the iNDVI spatially from 0 to 100% using uniform maximum and minimum iNDVIs across the four schemes, a productivity-drought condition index (PDCI) for each pixel was developed. Drought was identified if the PDCI is < 40% and was classified into four classes: extreme, severe, moderate and mild. Risk of yield loss was assessed as the product of hazard times vulnerability. Hazard was assessed by the PDCI value (or area under drought) and vulnerability by the normalized negative anomaly below the detrended crop yield line. Our results show differences in performance both temporally and spatially amongst the schemes. A median PDCI of 37.4 to 46.6% indicates mild drought to no drought conditions, respectively. The median percentage area of the schemes under drought amounted to 21.9 to 64.3%. Risk due to drought severity occurred 0 to 40% of the years. The risk rate, i.e. decline of sorghum yield per 1% increase of PDCI-based risk, ranged from -26.4 to -49.4 kg/ha/%. For each 1% increase in area under drought, the sorghum yield from the schemes declined from 22.5 to 36.5 kg/ha. These results agree well with the farmers’ perception of strong effects of drought on sorghum yield and have marked implications for food security in the region. Since the adoption of new technologies builds on own experience and trust in new technologies, the agreement identified herein between farmers’ perception and the PDCI-based indices suggests the potential of fostering remote sensing technology in farmers’ decision making.

ABSTRACT. The problems of water resources management are increasingly worrying, especially for countries with limited water resources. This management is all the more pressing because of the increasing pressure on these resources, especially for agricultural needs in order to ensure food security. Among theses resources, coastal water tables play an important role for ensuring drinking water and water for socio economic activities and particularly for agriculture but there are subject to marine intrusions. Also, as an impact of climate change, populations tend to immigrate to coastal regions which increases the pressure on these resources. This is the case of Morocco where the movement of populations towards the coasts has greatly increased in recent years. Face to such problems, the protection of these resources becomes essential. Thus, to better manage and protect these water resources, it is essential to understand their hydraulic functioning, know their current state and assess their vulnerability to the advancement of the salt water. In this sense, this study proposes a new method, called DCG method, to assess and map the vulnerability of coastal aquifers. This method introduces a vulnerability index Iv, based on the combination of the effect of three key parameters. These are the Distance from the sea, D, the hydraulic Conductivity of the aquifer, C, and the hydraulic Gradient G. The weights of the three parameters were determined using sensitivity tests and multiple linear regression analyzes carried out on data from certain groundwater monitoring wells. This method, inspired from the GALDIT method, aims to improve the previous method by reducing the number of parameters and consequently avoiding redundancy of certain parameters. As an application, we considered the coastal aquifer of the «Dradère-Souiere» plain in the North-West of Morocco known for intense agricultural activities and a very dense population. This new method could be adapted and applied in other coastal regions.

ABSTRACT. Given the dwindling groundwater resources of Western Kansas and to ensure their long term sustainability for agricultural production, we must implement more efficient irrigation management practices that can address the two most prominent challenges in the area: the prevalent impacts of extreme climate conditions on crop yield, and the excessive withdrawal of water resources. Our research employed the DSSAT-CERES Maize model to assess the efficacy of evapotranspiration-based (ET-based) irrigation scheduling in improving Maize crop resilience to extreme growing-season climate conditions. We conducted a 30-year simulation on twelve different irrigation treatments defined by four ET requirement thresholds (15mm, 20mm, 25mm, and 30mm), each replaced at three levels (50%, 75%, and 100%). A baseline for comparison, referred to as the farmers' choice was provided, where irrigation was initiated automatically when the plant-extractable water in the soil profile dropped below 50%. In comparison to the farmers' choice, we found that applying a 75% deficit of the cumulative ET of 30mm or 25mm maintains yield loss below 12%, saves up to 20% on water-use, and can improve water productivity by up to 6%, under normal weather conditions and when the maximum temperature and the duration of dry periods are increased by up to 4°C and 1 day, respectively. ET-based deficit irrigation adapts well to extreme heat and water stress, bearing important implications for irrigation management decisions in the future.

ABSTRACT. Irrigation is by far the largest consumer of freshwater worldwide. Thus, effective water management in this sector is crucial to enhancing water productivity (WP). In this study, a physically based agrohydrological model, the Soil Water Atmosphere Plant (SWAP), was used to investigate the WP of the main irrigated crops and water balance in the Furfuro irrigation scheme, Ethiopian Rift Valley. The SWAP model requires meteorological, soil, crop, and water data to simulate soil moisture and crop growth. The meteorological data (1991–2020) was collected from the Ethiopian National Meteorology Agency. The physical properties of the soil were determined in the laboratories. The basic crop data for selected crops was collected from Food and Agricultural Organization (FAO) documents. Field experiments were conducted at the command area in 2022–23 to collect data for the calibration and validation of the SWAP model. The field experiments were conducted on six experimental plots using the main irrigated crops (wheat, onion, and tomato) in the study area. The six experimental plots were categorized into two groups: Researcher plots and Farmer plots. Each group contains three plots, one for each crop type. Crop water requirements and irrigation scheduling were determined for researcher plots based on climatic, crop, and soil data of the area. All irrigation practices (amount and timing of application) and field management for farmer experimental plots were carried out by farmers based on their own experiences. However, the depth of irrigation water was measured during each irrigation at all six experimental plots using a 5.08*90 cm Cutthroat flume. Soil moisture content after each irrigation (for the wheat plot) was determined using the gravimetric method. Crop data such as leaf area, growth stage-based dry matter, and yield were collected from each experimental plot. The SWAP model was then calibrated and validated using soil moisture and crop growth data collected from experimental plots. The water balance components (rainfall, irrigation, transpiration, evaporation, and percolation) of the experimental plots were simulated using the calibrated SWAP model. The WP of the main crops grown in the study area was then determined using the simulated water balance components and measured yield in the experimental plots. The results indicated that the simulated irrigation depth at both researcher and farmer plots accurately represented the field condition. There was no significant difference between the researcher and the farmer plots in the evapotranspiration of the same crop. The percolated depth was 210.9 and 308.5 mm for wheat, 167.1 and 252.6 mm for onion, and 169.8 and 253.9 mm for tomato at the researcher and farmer plots, respectively. The physical and economic WP of researcher plots was greater than that of farmer plots at all water balance components. The physical and economic WP of wheat was lower than that of onion and tomato in both researcher and farmer plots, and tomato demonstrated higher physical and economic WP in both researcher and farmer plots. The findings in this study can provide technical assistance for effective irrigation water management to save irrigation water and enhance WP.

ABSTRACT. Flash floods are serious phenomenon that attacks and troubles people in many areas’ under-mountain region. Despite water scarcity, continuous prevalent droughts and infrequent rainfall in arid and semi-arid areas, their recent floods demonstrate that flooding is more severe and life-threatening. Even in recent times, the floods that have occurred in arid and semi-arid regions have caused a large number of fatalities and considerable economic damage in these regions. For example, catastrophic floods struck eastern Libya in September 2023 following the Daniel storm, resulting in more than 10.000 deaths, at least 90,000 displaced people, and millions of euros in economic damage to homes, businesses, and infrastructures. There are several unique factors that make arid and semi-arid regions susceptible to severe flooding and unexpected flood damage. On the one hand, the high diversity of climate, geography, hydrogeology, and land use poses difficulties for local flood managers. On the other hand, human and system-related challenges such lack of warning, drought-based management and institutional frameworks have adverse effects on Flood Risk Management (FRM). All of these facts emphasize the need for a comprehensive understanding of FRM challenges in arid and semi-arid regions in order to mitigate the negative impacts of floodings on the environment, economy, and society. The behaviors and impacts of floods are different based on the climatic regions and the adopted comprehensive FRM. To understand such differences, two case studies were selected for the analysis: Wadi Derna in Eastern Libya and Timor-Leste. The current flood assessment in the basins was analyzed, and the hazards associated with flood phenomenon were assessed for various calculated rainfall return periods. To this end, a flash flood index was calculated as a basis to understand the impact of flash floods (FF). A coupling of this index with the FF histories was included to provide a comprehensive overview of the FF vulnerability of the basins. A comprehensive methodology for mapping climate change-induced flood and drought risks has been developed by the consultancy. This includes integrating bottom-up assessments of climate vulnerability and adaptive capacity in targeted communities, model tool for calculating climate hazards and their impact, spatiotemporal variability of rainfall occurrence, climate change projections, and data on planned upstream dam developments. By taking into account these factors, we assure a comprehensive assessment of risk zones at both the district and community levels. This approach enhances the accuracy and reliability of the risk maps. Dams failure would be among the first indicators of climate change; they are a mirror to our collective understanding of natural hazard risk. Dams, now, contend with events that the designers never conceived. In dry regions, single mitigation measures, including storage dams, recharge dams, artificial lakes and embankments, are implemented, although soft mitigation measures such as early warning systems are not dominant,. The analysis demonstrates that a single management strategy under climate change impacts is insufficient to reduce flash flood risks. To reduce vulnerability to the impacts of climate change in Libya an integrated strategy is required.

ABSTRACT. In rainfed ecosystems, availability of soil moisture during crop period especially at critical stages is most critical to sustain crop yields. Among several available options, in-situ soil and water conservation measures assume significance in meeting crop water requirement. Rainfed field experiment was conducted with an objective to know the effect of water conservation measures on water use, crop performance and economics of rainfed sunflower + pigeonpea in Vertisol during Kharif 2021 and 2022 at Raichur, India. The experiment was laid out in split plot design replicated thrice. Moisture conservation practices were the main plot treatments imposed before planting. These were raised bed, ridges, and furrow, tied ridges and furrow, conservation tillage, flatbed sowing and opening furrow after every three rows at 30 days compared with flatbed sowing as a control and farmers’ practice. Subplots were sunflower + pigeonpea (1:1), sole pigeonpea and sole sunflower. Sunflower was planted at 0.6m × 0.3 m and pigeonpea at 1.2 m × 0.2 m. Total rainfall received during cropping period was 933mm and 448mm. The seasonal consumptive use, profile soil moisture, effective rainfall, bulk density, and porosity were measured at regular intervals. Rainfall use efficiency and energy indices were worked out by considering grain yield, input, and energy of the system. The results showed pre-sowing land configuration of ridges and furrows produced higher sunflower (59.6 and 66%) and pigeonpea grain yields (85.2 to 128.7%) over traditional flatbed sowing. Among cropping systems, higher yield was obtained in sole sunflower and pigeonpea over the respective intercropping. Lower soil bulk density and higher porosity was in ridge and furrow. Significantly higher soil moisture both at 0-15 and 15-30 cm were obtained in tied ridge and furrow (12.3 and 12.4%) and ridge and furrow (11.8 and 12.0%), while it was lowest in flatbed sowing (5.0 and 5.1%). Combined effect of sunflower + pigeonpea (1:1) grown on ridge and furrow method produced significantly higher sunflower and pigeonpea equivalent yields, land equivalent ratio (1.54), output energy (54,707 MJ ha-1) energy ratio (5.04), net returns (₹120,308 ha-1) and benefit: cost (4.18). The study summarizes sunflower + pigeonpea (1:1) cultivation under ridge and furrow was found to enhance yield, economics, and resource use, it can be extended to similar ecosystems of Vertisol.

ABSTRACT. In the arid landscape of the Gulf Cooperation Council (GCC) countries, water scarcity is a critical issue exacerbated by rapid economic development and population growth. Qatar, in particular, has adopted innovative solutions to address its water needs. This paper extensively examines Qatar's utilization of non-conventional water resources, primarily focusing on desalination and treated municipal wastewater. It delves into the status of non-conventional water in Qatar, emphasizing its impressive 97.3% reuse of desalinated water. The study explores best practices in managing non-conventional water resources, including advanced desalination technologies and wastewater treatment methods. Socio-economic aspects of water resource utilization are discussed, showcasing Qatar's economic and societal benefits. Governance of non-conventional water, including legal frameworks and private sector involvement, is thoroughly analyzed. The paper also highlights Qatar's efforts in national water conservation awareness and its role in research and development. Future directions and concerns are addressed, along with the costs of desalination plants. Furthermore, the importance of international cooperation and partnerships is underscored. In conclusion, this paper provides a comprehensive overview of Qatar's leadership in sustainable water management and its significant contributions to non-conventional water resource practices. Through strategic planning and cooperation, Qatar remains committed to securing its water resources and ensuring a prosperous and water-secure future.

ABSTRACT. 4-Nitrophenol (4-NP) is one of the anthropogenic nitroaromatic compounds used. It is toxic pollutant released into the environment through their wide use as dyes, pesticides, plasticizers, explosives, and solvents. It has been classified as a priority pollutant, by the United States Environmental Protection Agency and it can cause considerable damage to the ecosystem and human health. Its extensive use causes it to reach the soil and water resources resulting in environmental pollution and ecological stress, where they cause deleterious effects to the biological population. Efficient degradation of nitrophenols in aqueous effluents is important to minimize its environmental problems. The conventional chemical and physical methods for 4-NP removal exhibit high efficiencies but these involve high cost and lead to secondary pollution. Alternative approaches like bioremediation, which exploit the degradation potential of microbes to catalyze the breakdown of nitro-phenolic compounds to less toxic or nontoxic compounds, are gaining attention. Exposing the microbial catalysts to the substrate at an appropriate concentration to prevent nutrient limitations as well as substrate inhibition and administering the toxic shock loads generated by unintended variations in flow or composition of industrial effluents in the conventional biological treatment are the major concern. One strategy that facilitates controlled delivery of the pollutant at sub-inhibitory levels to the microbes for the occurrence of bio-catalysis is the two-phase partitioning bioreactor system. This work presents the biodegradation of 4-NP using freely suspended cells of Nocardia hydrocarbonoxydans, NCIM 2386 (Nch.) by implementing a two liquid phase partitioning system in a pulsed plate column (PPC) bioreactor (TPPBR). Nch cannot be used for degradation of 4-NP at concentrations above 300 ppm in a single-phase aqueous phase systems due to toxicity and substrate inhibition effects. Based on the biodegradability studies in a PPC, Nch. was found to possess the ability to degrade high concentrations of 4-NP in a two-phase partitioning system with 2-undecanone as a solvent phase. The pulsating action plays a vital role in enhancing the mass transfer between the phases, thereby increasing the degradation. The degradation was found to be highest at a frequency of 20 min-1 and amplitude of 6.5 cm. In TPPBR around 91 % to 79 % degradation of 4-NP could be achieved with initial 4-NP concentrations of 500-2000 ppm with free cells, thus confirming the potential of TPPBR for treatment of water contaminated with high concentrations of 4-NP. Hence the PPC as a TPPBR can overcome the drawbacks of substrate inhibition and toxicity effects. Air flow rate and inoculum size showed positive effect by reducing the time required for biodegradation of 4-NP. The aqueous to solvent phase volume ratio was determined to be a significant factor in TPPBR and 3:1 ratio was found to be optimum for efficient degradation. Thus, the findings of this work illustrated that the performance of PPC as TPPBR is potentially effective for treatment of 4-NP, present at inhibitory or toxic concentrations in wastewater with freely suspended cells of Nch.

ABSTRACT. ABSTRACT A contract project was carried out to collect data on the quality and quantity of 17 petroleum and non-petroleum industrial wastewater from different sources in Shuaiba area in Kuwait over a period of one year as well as developing a database of such characteristics and attributes using geographic information system (GIS) technique. During the field visits, a specially designed field surveys were submitted to the owners of industrial facilities in Shuaiba industrial area in Kuwait. In this study, wastewater samples were collected and analysed on monthly and biweekly basis from 17 petroleum and non-petroleum factories of Shuaiba industrial areas. This paper was targeting assessment of total phosphate in the raw wastewater for factories of Shuaiba industrial area. The field wastewater data indicated presence slightly acid to alkaline (5.7-12.9), reduced to oxidized environment (-431 mv-617 mv) and freshwater to brackish water (333µS/cm-33,090µS/cm). The laboratory results revealed that total phosphate concentrations for wastewater of 17 factories ranged between 0.1 mg/l and 94.8 mg/l. The mean values of total phosphate concentrations for wastewater of 17 factories were meeting the maximum limit (30 mg/l) set by KEPA for irrigation water purposes. The mean value of quantities of wastewater generated from 17 factories was found 62.28 m3/week. The large quantities of raw wastewater generated from these factories can be used safely as irrigation water with respect to total phosphate concentrations.

ABSTRACT. One-third of the world faces water insecurity, and freshwater resources in coastal regions are under enormous stress due to population growth, pollution, saltwater intrusion, climate change and political conflicts. Interdisciplinary researchers from 33 countries aims to address whether and how offshore freshened groundwater (OFG) – groundwater stored in the sub-seafloor with a total dissolved solid concentration below that of seawater – can be used as an unconventional source of freshwater in coastal regions. This scientific network intends to 1) identify where OFG is found in coastal areas in Europe and neighbouring countries and in what volumes, 2) delineate the most appropriate approaches to characterise it, 3) identify the most cost-effective strategy to utilise this resource, and 4) investigate the legal and environmental implications of a sustainable exploitation of OFG resources. The network will foster cross-disciplinary and inter-sectoral collaboration between currently isolated fields of research to reduce the gap between science, policy making and society. It provides high-quality training and funded scientific exchange missions to develop a pool of experts able to address future scientific, societal, and legal challenges related to OFG. The first exchange missions in 2023 allowed the creation of a repository of European OFG data, such as well composite logs, core samples, and electromagnetic transects. These data will be used to identify potential areas for the exploration of OFG. The network supported several other investigations around the world, including on the Atlantic Margin of North America, Canterbury Bight in New Zealand and the East China Sea. Geological stratigraphic models, hydrogeological simulations as well as groundwater salinity models have been developed and tested over the Israeli and Lebanese continental shelf, among others. In 2024, the network will review existing instrumentations, methods and approaches that have been so far used to study OFG around the globe and develop best practice strategies and guidelines for OFG exploration. It will also review existing policies for onshore aquifers and offshore resources to outline recommendations for action plans, protocols and legislation for OFG utilisation at the local to international levels. This interaction between leading experts from academia, government entities and industry will foster new science-based approaches and concepts that will lead to breakthroughs in OFG characterisation and utilisation, translate into future market applications, and deliver recommendations to support effective water resource management.

ABSTRACT. Salalah, in the southern coastal region of Oman, has a unique climate in the Arabian Peninsula. The city lies in the coastal plains surrounded by steep mountain cliffs that trap the monsoon clouds during summer and cause orographic rainfall. During the summer, the ephemeral channels have plenty of water that recharges the aquifers. Obviously, the majority of the agricultural activities are taking place in the fertile plains along the coast. The population has increased from 132,000 (in 1993) to 333,000 (in 2021). Moreover, the agricultural area has increased from approximately 5,000 ha to 24,500 ha from 2014 to 2018, solely depends on groundwater for irrigation. Consequently, the pumping rates have exceeded the recharge rates by far, causing seawater intrusion into the coastal aquifer that provides for the domestic consumption of freshwater as well. To counter the seawater intrusion, the artificial recharge of the coastal aquifers commenced in 2003 using tertiary treated wastewater by 40 injection wells having a capacity of 27000 m3. Moreover, two recharge/flood protection dams were also constructed to enhance the recharge. In the present study, MODFLOW and MT3DMS models have been utilized to assess the performance of the recharge schemes in the Salalah coastal plain aquifer. The model was calibrated and validated at steady state and transient state using data from 2000 to 2019. It was used to define the aquifer properties such as hydraulic conductivity, specific yield, and vertical anisotropy. MODFLOW results were mapped to MT3DMS in order to simulate solute transport at transient state. The longitudinal dispersivity and porosity of the aquifer were defined through the calibration and validation of the model. MODFLOW calibration and validation results showed good agreement between the field observed head values and model computed values with RMSE of 0.65. The sensitivity analysis indicated that the hydraulic head had more sensitivity to the hydraulic conductivity among the three calibrated parameters, while groundwater abstraction sensitivity was the highest among all the input parameters to the system. The study indicated a clear impact of seawater intrusion at the coastal side of the Salalah Plain. The predictive modeling indicated an average of 1.5 m drop in hydraulic head across the whole study area by 2040, while the seawater intrusion effect was expected to increase at the coastal side with potential extension to the central area of the Salalah plain. This study will be helpful for the public authorities, researchers, and practicing engineers to mitigate seawater intrusion in the coastal aquifers using artificial recharge.