ABSTRACT. The Azraq Wetland Reserve (AWR) with a 74 sq. km surface area in the eastern desert of Jordan is one of the wetlands preserved under the RAMSAR Convention since 1977. Less than 15% of the wetland area has been preserved compared to the past. The wetland is located in the center of the Azraq Basin, a transboundary basin with a semiarid climate. Pumping groundwater from the deep aquifer complexes meets most of the water demand. This study aimed to estimate groundwater fluxes and depths in and around the AWR during the recent period (2013-2020). More specifically, the model is intended to be used a) as a tool to facilitate understanding of the groundwater flow dynamics in the AWR, b) as a decision-support tool to preserve the groundwater-dependent wetland ecosystem; c) to determine critical areas of decline in groundwater levels. A regional, three-dimensional transient groundwater flow model was developed using Modelmuse 5.1.1, which is a public-domain graphical user interface of the finite-difference flow model MODFLOW-2005. The model was calibrated using the automatic parameter estimation code PEST. The measures of model fit suggest overall acceptable model errors. The simulation results appropriately represent the regional patterns of groundwater flow in the Azraq Basin and yield meaningful water balances comparable with previous studies’ findings. The modeling results provided critical information regarding groundwater level changes over the past eight years. It can be concluded that groundwater levels in the AWR are highly dependent on groundwater flow and budget components in the basin as a whole. According to the model results, the groundwater level in the AWR declined by an average of 0.83 m per year. Furthermore, the model results indicated that the groundwater depth under the AWR increased to 22m below the ground level at the end of the simulation period.

Acknowledgment: This study is funded by the PRIMA program supported by the European Union’s Horizon 2020 framework program under grant agreement No: 1924, project RESERVOIR.

ABSTRACT. Coastal recreational waters are under intense pressure due to increasing coastal development, impacting the marine ecosystem. Environmental authorities have set limits on contaminant concentrations to regulate the management and monitoring of bathing water, in order to protect public health. The temporal and spatial variability of pollution pressures of the coastal waters resulting from river discharges is the main cause of environmental problems along the coastline. The ecological quality assessment based on the repeated measurements sustained over a historical time frame is often challenged by a limited spatial and temporal frequency of data. Instead of dealing with general statistical measures, we discuss an alternative approach, which is based on quantifying the uncertainty using the full probabilistic description for selected quality indicators. The impact coming from the river estuary is analyzed using the loading capacity concept to examine the exchange flows and loading dynamics of nutrients discharged in coastal waters. We have analyzed the freshwater flow over the salinity gradient in the estuary to assess how it affects quality indicators in transitional ecosystems. Our methodology has been developed and is presented in a case study that focuses on coastal and transitional water bodies in the Eastern Adriatic Sea in Croatia, as well as the Western Adriatic Sea in Italy.

ABSTRACT. Precipitation in Northern Oman is scarce and most of it evaporates soon after most rainfall events. Spatial distribution of this rainfall differs from event to event and from year to another. However, due to surface hydrology, the geographical location of runoff networks and ponding can be mapped through satellite imagery analysis during and soon after flood events. In this work, several sources of satellite images from LEO satellites including small satellites were analyzed to map inundation area and long-term flowing wadis. By considering the surface geology and soil types, surface zones of high groundwater recharge in some parts of Northern Oman were mapped. Comparison between these zones and shallow groundwater fluctuation proof the reliability of such method in detecting groundwater recharge areas in arid country. Advanced satellite images analysis by using AI might help in analyzing the huge database of satellite imagery.

ABSTRACT. Water is a very important resource on the earth and underground aquifers serve as a natural freshwater source for the world’s population. Anthropogenic activities along the coastal plains of Andhra Pradesh rely extensively on coastal fresh groundwater resources that are pumped at unsustainable rates causing groundwater decline and water quality problems due to saline water intrusion. In this study, an attempt was made to investigate submarine groundwater discharge (SGD) and saline water intrusion (SWI) zones of the coastal aquifer of the south-eastern coastal plains of Andhra Pradesh. The occurrence of SGD and SWI have been identified adopting different methods such as groundwater dynamic, LANDSAT resultant sea surface temperature (SST) variance and site-specific water characteristics for the conservation and management of groundwater resources along the southeast coast of Andhra Pradesh.

The groundwater elevation above mean sea level was mapped, using 600 monitoring well data (2018-2019) collected from state/central groundwater departments, by inverse distance weighted (IDW) interpolation technique. The hydraulic gradient values vary from −11 to 250 m in post-monsoon and −14 to 250 m in pre-monsoon. Satellite thermal medium spatial resolution images (LANDSAT 8 thermal infrared sensors, TIRS) and advanced space-borne thermal emission and reflection radiometer (ASTER) data were used for the estimation of sea-surface temperature (SST). Sea surface temperature anomaly for 2017, 2018 and 2019 varies between 21–39 °C, 15–34 °C and 20–39 °C. Around 234 (porewater, groundwater and sea water) samples were collected along ~450 km coastline to evaluate the submarine groundwater discharge and saline water intrusion zones. In-situ physio-chemical parameters such as EC, TDS, pH, DO, temperature and salinity of porewater (at every 1 Km except non-accessible coastal zones) and groundwater/seawater were analyzed (at every 5 km) for identification of SGD zones in the study area. It is concluded that out of four districts, three districts (i.e. Krishna, Guntur and Nellore) were prone to saline water intrusion whereas Prakasam district was susceptible for submarine groundwater discharge conditions. For the first time, this kind of study (preliminary) was carried out that helps further in meticulous scientific analysis of demarcation/separation of fresh SGD and saline water mixing zones as well as future sustainable water resources management along the water-stressed coastal Andhra Pradesh region.

ABSTRACT. Jordan has limited water resources with a rapidly increasing in its population. It has a water scarcity that its quality has rapidly deteriorated as a result of intensive traditional industrial and agricultural activities. Furthermore, it has an accelerated urban expansion that has a negative influence on its water scarcity in terms of quality and quality. Therefore, Jordan needs research that correlates the sources of pollution with water resources. By using an integrated approach of remote sensing and Geographic Information Systems (GIS) we carried out maps that show the current locations of water resources, pollution sources, and urban expansion. However, by using spatial analysis we generated a spatial map for the optimized sites for agricultural, industrial, and urban activities in order to protect the water resources from pollution. We found that Jordan has complicated geography in terms of location and topography that has a significant influence on the spatial distribution of water resources, population density, and urbanization. Accordingly, hydrological and natural risks conflict and are generated such as water shortage and contaminations and groundwater depletion. We found that investigating these conflicts is complicated and needs a sophisticated approach considering all the spatial parameters that control these conflicts. We found that disciplines between sciences must be considered when the conflict concerns water resources.

ABSTRACT. NCT Delhi with its geographical area of about 1483 km2 had population of ~16.8 millions in the year 2011 with the water demands varying between 708-926 MGD (Million Gallon per day), projected to have almost double by 2021. The current rate of extraction of groundwater ~80 MGD, with less recharge causing depletion of groundwater levels and 15 assessment units out of 34 units are under the category of over-exploited. In addition, groundwater has issues of salinity, high nitrates in some parts of NCT Delhi.

NCT Delhi has the Yamuna flood water flow causing flood like situation during monsoon period, and on the other hand it has a number of surface water bodies, which have been witnessing reduced surface storage capacities because of siltation and other factors. The augmentation of groundwater resource in depleted aquifer is urgently required to avoid aggravation of future geo-environmental hazards and also to match increasing groundwater demands. This eventually suggests the need of artificial groundwater recharge in the form of managed aquifer recharge (MAR) by identifying potential source of water for MAR. In the present study, to work out the feasibility and scope of MAR in NCT Delhi have been analyzed. Some of the recommendations of the studies are: rejuvenation of surface water bodies located on the depleted aquifer together with their catchment areas overhauling is recommended in the New Delhi, Central, South and South East districts. Use of treated effluents from STPs after tertiary treatment is seemed to be a logical way forward to have source water for MAR in areas of interest for use by overland applications, recharge basin approach, furrow methods, feeding to surface water bodies in South-west, New Delhi, Central Delhi, and South Delhi (Chattarpur) area.

ABSTRACT. Gulf Cooperation Council (GCC) countries are arid and hyper arid region with scarce renewable freshwater resources, and hence depending on desalination to overcome the deficit in water supply. Due to the rapid growth in population and economic development, it is expected that the total annual GCC water demand will increase by 40% in 2030 and may reach more than 50 Billions Cubic Meters (BCM). The current daily GCC desalination capacity is about 18.2 million cubic meters (about 6.64 BCC annually) with a prediction to be increased by about 40% by 2030. GCC countries account for about 60% of global water desalination capacity, producing around 40% of the global desalinated production using more than 400 desalination plants. However, desalination sector has environmental and economic constrains and use over 30% of the region energy, thus many technologies are being tested and implemented to reduce the environmental impacts and reduce the costs. The carbon footprint is 3.0 and 2.5 kg per cubic meter for the thermal and RO desalination technologies respectively. GCC countries aim to boost their capacity by 37% over the next five years, by investing about US$100 billion to address their freshwater challenges. The GCC desalination sector capacities, socio-economic aspects, brine water discharge, carbon footprint, energy consumption and costs were discussed. The different GCC desalination policies, their environmental impacts, the emerging techniques, which could help to reduce the environmental negative impact, energy use and costs were also assessed. Different mitigation strategies to lower the environmental impacts and reduce the desalination cost are analysed. The results indicating that emerging and innovative technologies promise up to 17% annual energy savings in desalination sector in GCC countries by 2030. The study recommended to carry out detailed environmental impact assessment before the construction of any new desalination plant or prolonging the capacity of the prevailing one for limiting the adverse impact of the facility. It has been found that, the use of renewable energy in desalination is recommended as an impressive idea to reduce the environmental impacts and energy costs.

ABSTRACT. This text will propose schemes of Water, Heat, Electricity and Renewable Energy including Fuel Production which are to meet rationalized demands. Such schemes will propose integrated processes with hybridization. This will particularly look into the utilization of renewable energy (energies) in hybrid integrated approach with conventional fossil fuel.

Mankind in his endeavor for better living had searched for and came across means of harvesting natural resources. Among which there are few historical references which are related to direct solar desalination. The earliest would be Solar heat utilization in covered caverns followed by concentrator(s) as either lenses or mirrors. Then towards the end of the last millennium there are references to couple of direct solar desalination citations.

Solar Energy is currently utilized for heat and electricity generation. That is to say that, there are few solar energy harvesting approaches which are being successfully deployed as input energy sources for water desalination and heat as well as electricity generation. The most common schemes are addressed. These are Photo-Voltaic (PV) Cells which are based on Solar panels and thermal heat concentration utilizing stationary or solar tracking. The earlier, i.e. PV cells with abundance of (white) sand (silicon oxide) could lead to creation of an incubator for this technology in this region. Such industry would also require the development and then production of complimentary components. It would also be worthwhile to note that sand is a two edged sword as far as PV is concerned. Since silicon is a base element in PV panels production. Yet sand (in the form of dust) along with salty humidity are plagues to PV panels’ performance. Meanwhile, it is important to note that during the last century till now (in this 21st century) conceptual process integrations were initiated. Such development was put up to promote Systems and Process Improvements including Heat Harvesting by Solar Ponds (SP) and Heat Absorption as well as Pressure Retarded Osmosis (PRO). Couple of other Renewable resources are to be looked into. These are Wind and/or Geothermal Energy. The primary aim was to render an environmental and cost effective segregated versus integrated water, power, heat and renewal energy production schemes, e.g., Hydrogen and Oxygen Production by Electrolyzes of Modified Seawater. As an introduction and for the purpose of comparison other aspects will be addressed in some details as found pertinent. Most important of which would be a historical review, thus casting light onto earlier mentioned desalination including few personnel contributions as well as making reference to heat and motion as pre-requisites for electricity and water production. Thus this text will encompass innovations and process improvements especially as related to desalination as well as future requirements. Among these requirements and for the purpose of completing the picture; DEMAND AND UTILIZATION FACE OF THE COIN PLUS EXTENDED CLOSING NOTES WILL BE ADDRESSED IN (THE LAST) CHAPTER 3 SINCE CHAPTER 1 IS AN INTRODUCTORY CHAPTER THAT INCLUDES AUTHOR’S BACKGROUND, WHILE CHAPTER 2 IS MEANT TO COVER THE SUPPLY FACE OF THE COIN WHERE PROPOSED CONCEPTS ARE PRESENTED.

ABSTRACT. Global demand for clean, fresh water is rising due to the growing world population, industrial activities, and climate change. The decay of natural water resources in the last few decades has also been recognized as one of the main environmental challenges on a global level. Desalination methods have become more essential and are critical for producing fresh water from salty water to meet the increasing water demands, especially in water-stressed countries. The GCC countries are among the fastest-growing economies, with a total population of 56 million and an average water consumption of 560 L/capita/day. This consumption rate continues to remain high despite the warnings and several initiatives, especially given insignificant non-renewable water resources, precipitation of 70-140 mm a year, and high temperatures evaporating the little rainfall the countries get. Moreover, due to the intense oil and gas industries, GCC countries have very high CO2 emissions per capita worldwide.

Microalgae have recently received more interest since they can grow and produce valuable byproducts under various climatic conditions. Microalgae are plant-like species that thrive in a nutrient medium containing compounds such as water, salt, nitrogen, phosphorous, inorganic nutrients, CO2, and light energy for photosynthesis. Biodesalination using microalgae is a novel method based on salt adsorption and accumulation by various salt-tolerant algae species. This new method causes less damage, negative environmental impacts, and lower energy consumption and costs. The environment of most GCC countries offers rich biodiversity and microalgae species that grow under sunlight and in the presence of CO2, which are widely available in the GCC region. The ideal growing conditions and available resources in the GCC region provide a perfect environment for the large-scale cultivation of microalgae.

This study aims to investigate the biodesalination of saline water and CO2 biofixation using microalgae as a sustainable and energy-efficient approach to desalinate seawater for agricultural and municipal water use while producing valuable products. The emphasis of this research will be on using valuable local resources and collecting local microalgae strains with high tolerance to increased water salinity and CO2 levels and developing growth media with optimized operating conditions (e.g., the type of microalgae species, nutrients amount, light intensity, temperature, and pH) in order to increase the microalgae productivity and desalination performance. The outcomes of this research can play a significant role in supporting the local economy by offsetting greenhouse gas emissions and producing usable water and bioproducts, which are vital in achieving a more sustainable future for GCC countries.

ABSTRACT. Brine water is known as a byproduct of many industrial processes, such as desalination, power plant, and natural gas extraction. Brine often contains hazardous substances such as lead, zinc, copper, and naphthalene in addition to its high salinity. Several studies indicated that slight variations in salinity and temperature could significantly influence the marine ecosystem. Various disposal techniques have been implemented to minimize the environmental impact of brine, including deep well injection, evaporation ponds, surface water discharge, and sewer discharge. In recent years, there has been significant growth in demand for carbon fiber. According to the literature, the global demand for carbon fibers was approximately 35,000 tonnes in 2008, and by 2014, it is predicted to quadruple, growing at a pace of more than 12% annually. There are three main technologies that have been classified for recycling carbon fibers. Mechanical recycling involves shredding, crushing, or any other mechanical approach to break down the fibers into small sizes. The second recycling process is thermal recycling which requires heat to break down the scrap composite and burn the resin matrix, by this, the carbon fiber can be recovered. The final recycling technique is chemical recycling, in this technique, chemical solvents must be used to degrade the resin. Usually, this approach results in a clean fiber with high mechanical properties. This research aims to present a new method in which waste carbon fibers will be recycled, activated, and then reused as an absorbent to heavy metal from brine. When carbon dioxide gas is passing through a mixture of brine water and activated carbon fiber, the brine salts will react with the functional group on the surface of the activated carbon fiber. Accordingly, the process will implement three advantages; carbon fiber waste utilization, reject brine treatment, and CO2 capture. However, the efficiency of activated carbon for brine treatment can be affected by many factors such as the concentration of salts and heavy metals in the brine, the contact time, and the pH of the solution. Therefore, this research is important to design the treatment system appropriately and optimize the conditions to achieve the desired level of salts and contaminant removal. The initial findings of this research showed that desalination efficiency could reach 65-70% and with a promising CO2 uptake value. The presented research considered a promising way to utilize the waste carbon fiber for brine management and an effective way for CO2 capturing

ABSTRACT. A novel approach is presented involving a multichambered bipolar membrane electrodialysis system designed to concurrently address brine treatment and CO2 capture. The study employs a NaCl solution to represent brine and a simulated flue gas mixture comprising 10% CO2 and balanced air. The investigation focuses on evaluating energy consumption and the operational efficiency of the bipolar membrane electrodialysis process. Notably, the research demonstrates the practical application of this process by producing hydrochloric acid and sodium carbonate/bicarbonate salts. Titanium electrodes, with the anode coated in a combination of iridium and platinum mixed oxides, are utilized. This innovative technique proves to be cost-effective, environmentally friendly, and sustainable. The proposed method offers a promising avenue for the dual mitigation of CO2 emissions from flue gases and brine treatment within a single integrated process. This is particularly significant given that CO2 and reject brine constitute major pollutants associated with various industries.

ABSTRACT. Water shortage is severe in Saudi Arabia posing challenges to water supply in the agricultural, industrial, and municipal sectors. Groundwater plays a major role as the source of water in Saudi Arabia, and it should be exploited in a sustainable way to avoid adverse effects. This study was carried out in the watersheds of Jazan Province with the following objectives, (1) to understand the current water supply and demand scenarios, (2) to assess the water quality and processes controlling groundwater chemistry, and (3) to predict the flash floods and to use the flood water to replenish the groundwater resources. Of the 80 groundwater samples analysed, 85% had high hardness and high salinity resulting from saline sources, evaporation, and anthropogenic sources, thereby making it directly unusable for drinking. Nitrate and fluoride were the other contaminants at higher concentrations observed in 51% and 46% of the wells. Groundwater samples were close to saturation with calcite (51%), dolomite (39%), and aragonite (26%) minerals, and were undersaturated with calcite, aragonite, and dolomite minerals in 49%, 74%, and 61% of groundwater samples respectively. Mixing calculations indicated rainfall contributing between 5% and 53% to groundwater. Evaporation and infiltration of evaporated water are the major processes controlling the hydrochemical dynamics of groundwater, and seawater intrusion in many of the coastal wells is evident. These processes are confirmed by the stable isotope data (δ18O and δD). Quality of groundwater for various uses were ascertained. Drinking water quality index indicates that most of the samples (66%) fall under poor to unsuitable category. Highly vulnerable groups as per the total hazard index were as follows: infants > children > adults. Flash floods occur often in the region and the occurrence of these flash floods were predicted to identify the use of flood water for additional recharge. 48% of the study area are identified as high, 52% as medium, and low hazard degrees of flash floods. Groundwater recharge was calculated, and it ranges from 0.002 mm/km2/year to 8 mm/km2/year with an average of about 2.5 mm/km2/year. Rainfall-runoff inter-relation of study basins, assessed based on the integration of WMS and HEC-HMS models, indicates that the resulting runoff volume ranges from 18.5x106 m3 to 473.1x106 m3 at a recurrence period of 5 and 100 years at rainfall events of 65 mm and 116.8 mm respectively. These results will help stakeholders, practitioners as well as the decision makers to formulate groundwater management plans for the region.

ABSTRACT. In this research, a comprehensive approach is taken to mapping flood susceptibility in the Mekerra watershed, northwestern Algeria by integrating the Analytical Hierarchical Process (AHP), Geographic Information Systems (GIS), and a rainfall-runoff inundation model (RRI). The Analytical Hierarchical Process (AHP) is utilized to establish a decision framework, allowing for the systematic evaluation of various criteria contributing to flood susceptibility. AHP helps to prioritize these criteria based on their relative importance, providing a quantitative assessment of flood vulnerability in the study area. Geographic Information Systems (GIS) is employed as a powerful tool for data collection, integration, and spatial analysis. GIS allows for the incorporation of diverse datasets such as topography, land use, and hydrological characteristics, enabling a holistic understanding of the flood-prone areas and their spatial distribution. Additionally, a rainfall-runoff inundation model (RRI) is integrated into the study to simulate rainfall-runoff processes and flood inundation. This model takes into account satellite-based rainfall data and topographic inputs to improve accuracy in predicting flood behavior. By analyzing the spatial distribution of stream discharge during high flood events, the RRI model provides valuable insights into areas with elevated flood risk. Through the integration of AHP, GIS, and the RRI model, this research aims to generate a precise flood susceptibility map that aids in effective flood management, vulnerability reduction, and risk mitigation strategies. This approach allows for a comprehensive assessment of flood susceptibility by considering multiple criteria, spatial analysis, and rainfall-runoff simulations, providing valuable information for decision-making and disaster preparedness efforts in the Mekerra watershed.

ABSTRACT. Water, an indispensable element of life, has been a fundamental resource for the sustainability and development of human civilization since its inception. Throughout history, societies have settled around water sources, developed advanced irrigation systems, and devised strategies to preserve and manage these resources. However, arid and semi-arid regions worldwide present a unique paradox of water challenges and scarce environments rich in technology and innovation. One such paradigm is exemplified by Jaipur’s traditional water management system, which is a testament to human ingenuity during times of adversity. Jaipur, the capital city of Rajasthan, lies in the semi-arid desert region of India. This geographical location has a unique combination of weather conditions with extremely hot summers and uneven and scant rainfall throughout the year.

This study aims to explore the significance of traditional water management systems in Jaipur and examines how these structures are used for water-utilitarian solutions in semi-arid regions. The water management system of Jaipur was designed to efficiently accommodate the water needs of its residents through rainwater harvesting. These structures were designed to capture rainwater and store it for dry periods, reflecting a deep understanding of local hydrology and exhibiting a harmonious integration of engineering with functionality. Nevertheless, the challenges of the modern era, such as population growth, urbanization, climate change, and increased water demand, have prompted the need for innovative solutions beyond traditional methods.

Hence, a comprehensive research methodology with a multidisciplinary research design was adopted to achieve this objective. It involved an architectural analysis that examined the structural layout, focusing on features such as stepwells, underground channels, and storage reservoirs, and hydrological assessments that involved studying the hydrology of the region and catchment areas of the forts, along with rainwater harvesting and groundwater recharge techniques. By employing this comprehensive research methodology, this study highlights the adaptation of these structures to modern water needs and their contribution to the community’s water security, and examines how these water management techniques are used worldwide as innovative technologies to transform water management.

The relevance of this study extends beyond historical curiosity as it provides valuable insights for present-day water resource management in arid and semi-arid regions that deal with water scarcity exacerbated by climate change. By analyzing the sustainability of these traditional water management systems, this study offers potential solutions for adapting and modernizing these techniques to the current challenges. This bridges the gap between historical wisdom and modern innovation, underlining the importance of incorporating traditional knowledge into sustainable water management strategies. By examining the traditional water management systems in Jaipur, this study sheds light on the enduring wisdom of the past and its applicability in addressing existing water challenges. These findings have implications for policymakers, urban planners, and researchers working toward sustainable water management solutions in arid and semi-arid regions worldwide.

ABSTRACT. Land use land cover changes associated with urban development were found to significantly affect the watershed hydrology. Alteration of traditional flow paths, reduction of natural mitigation, increasing surface imperviousness, and rerouting of natural flow paths through artificial drainage systems result in increased peak runoff and rapid surface flow. As a result, the quick occurrence of high-intensity, short-duration rainfall events triggers extensive overland flow, resulting in flash floods. Flash floods are among the most devastating natural hazards in arid environments, causing considerable human losses and economic damage. To assess this rising risk, flash flood forecasting through hydrological studies is crucial. Understanding the dynamics of urbanization-induced land-cover change can help in coping with environmental changes, assist urban planning, and facilitate sustainability. LULC mapping and classification are done by applying machine learning algorithms on remotely sensed imagery. The present study aims to test the applicability of new remote-sensing data (PlanetScope imagery) and Sentinel-2 data to accurately identify and map changes in land use land cover associated with the urbanization of the WadiHam watershed. Wadi Ham is an arid ungauged watershed prone to Flash Floods, in Fujaira, in Northeastern UAE. The performances of several machine learning-based classifiers such as Random Forest (RF), Artificial Neural Network (ANN), and Maximum Likelihood Classifier (MLC) will be tested and compared for accurate generation of LULC maps, under arid environmental settings. The high-accuracy LULC maps produced will enable quantitative assessment of LULC changes through earth observations and serve as valuable input data for hydrological modeling. Implications of accurately representing LULC changes on hydrological models will be analyzed. Findings from this study will provide urban planners and policymakers with useful information to implement low-impact development (LID) and best management practices (BMPs) to increase urban resilience against flash floods and minimize the impact on the built environment.

ABSTRACT. In arid and semi-arid locations like Yalamlam, sustainable groundwater resource management is of utmost importance. The identification of appropriate regions for the recharging of groundwater is a crucial undertaking in addressing the issue of water shortage and maintaining the sustainable existence of aquifers in the long run. The present research utilizes the Analytical Hierarchy Process (AHP) methodology, in combination with Geographic Information Systems (GIS), to demarcate the zones with potential for groundwater recharge in the Yalamlam basin. The study technique includes the collection of fundamental hydrogeological data, such as lithology, land use, precipitation, slope, and soil properties. AHP is used to allocate relative weights to various characteristics, taking into consideration their importance in affecting groundwater recharge. GIS is then used to undertake the processing and analysis of these weighted layers, culminating in the production of a complete map depicting the potential for groundwater recharge. The integration of AHP with GIS enables a comprehensive evaluation of the many elements that impact groundwater recharge. The findings of the research indicate the presence of discrete zones with varying capacity for groundwater recharge in the Yalamlam area. Areas with significant recharge potential are often found in regions that exhibit favorable lithology, moderate slopes, little land use disturbances, and increased precipitation. On the other hand, regions characterized by poor geological features and intensive land use practices tend to exhibit a high prevalence of low recharge potential zones. The aforementioned results provide crucial insights for the implementation of sustainable groundwater management techniques, hence aiding in the formulation of policies pertaining to specific interventions aimed at groundwater recharge.

ABSTRACT. Drought is the most common natural calamity, affecting many parts of the world. It is not just the absence of rain but also the irregularity with which it falls during the season, the duration of the dry spell, and the effects it has had on the local economy, agriculture, and way of life. The meteorological conditions of a region have a direct impact on diverse water requirements and are associated with hydrologic, agricultural, and socioeconomic drought conditions. As a result, monitoring and determining the region's meteorological drought is critical for implementing appropriate water management techniques. This study aims to identify the best meteorological drought index for the Arid regions in India. Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) have been used to analyze drought conditions across different assessment periods. The meteorological data has been obtained from the Indian Meteorological Department (IMD), Pune at a resolution of 1⁰x1⁰. SPI and SPEI identify most of the drought events under moderate drought categories across all the assessment periods. Both of these indices identified Tamil Nadu with maximum extreme drought events. The correlation among these indices is observed to be maximum for Punjab and minimum for the Rayalaseema regions. Overall, the SPEI which takes care of temperature found to be more effective in drought analysis in the Arid regions taken in this study. The Modified Mann-Kendall test has been carried out to identify the trend of drought within these climatic subdivisions. It is hoped that the outcomes of this study will help in analyzing meteorological drought conditions critically within the region, thereby devising strategies that will be extremely valuable for water resource administration and related policy planners in the region.

ABSTRACT. Saltwater intrusion in coastal aquifers is a well-understood phenomenon that is aggravated by groundwater withdrawal that lowers the groundwater table. Saltwater intrusion is observed, measured and modelled extensively. Methods of combating the further advance of the saltwater front have been proposed and put into action. Natural and aggravated intrusion can be conceived as two first phases of the phenomenon. Today a third phase can be observed in coastal regions worldwide: it is characterized by the rise of the groundwater table. The rise can be attributed to decreased pumping, reduced evapotranspiration, land subsidence (all often side effects of urbanization of the coastal plain or land use changes in general) as well as sea-level rise. The rise of the groundwater table causes several new problems in the coastal regions, which are exacerbated by the fact that the rising water is saline. It endangers the foundations of buildings erected in the second phase of lowered water tables. Saline groundwater from shallow aquifers seeps into coastal lagoons and depressions affecting ecosystems. In this contribution we utilize a numerical model to demonstrate the three phases of seawater intrusion. The model simulates the progress and retreat of the saltwater front and the decline and rise of the water table in reaction of a hypothetical pumping regime, based on observations in the Oman coastal lowlands. The model results clearly indicate the developments of salinity and groundwater head in the mentioned phases. They demonstrate the crucial different behaviours in reaction of a changed pumping regime: the rapid response of the water table on one side and on the other side the slow reaction of salinity - the latter with a long tailing in the third phase. Concerning the modelling approach we outline how the changing water table can be simulated by a moving free boundary.

ABSTRACT. Africa’s Sahel region is home to some of the poorest countries in the world. One of the main causes of economic stagnation and high incidence of poverty in the region is environmental fragility which has major implications on community livelihoods. Although the situation of environmental fragility in the Sahel is concerning, till date, limited research has been carried out in the region to better understand the situation of environmental fragility and how it impacts community livelihoods. It is within this framework that this study examines the drivers of environmental fragility in the Sahel and its implications on community livelihoods in the region. Data collection was done through an in-depth review of literature. The findings reveal that, the main drivers of environmental fragility in the Sahel (categorized into climatic, socio-political, institutional, and economic) include: political instability (recurrent coup d’états), poor governance, armed groups and illicit economies, poor mastery of climate transitioning and adaptation mechanisms, volatile food prices and food insecurity, limited access to natural resources and livelihoods, rapid demographic growth which overwhelms state institutions, recurrence of hazards and extreme weather/climatic events, as well as poor landscape management practices which trigger land degradation. The worsening situation of environmental fragility in the Sahel has led to a deterioration of community livelihoods in the region especially for smallholders and nomads who constitute the overwhelming majority of the population. Improving governance, building peace, introducing nature-based adaptive solutions and formulating and implementing policies which redress the situation of environmental fragility will contribute enormously towards fostering development in general and community livelihoods in particular across the Sahel region.

ABSTRACT. Coming from the literature sources Managed aquifer recharge (MAR) is defined as the intentional infiltration of water into aquifers with the purpose of either later recovering that water for different purposes like agricultural, industrial, urban or obtaining an environmental benefit (Dillon et al., 2009). It has replaced the term “artificial recharge” which maybe evoked something what seemed to be unnatural in the environment (Dillon, 2005). There are different types of MAR methodologies and examples. Some of them were proposed or even already realized in frame of the DEEPWATER-Central Europe (CE) project. To increase long-term retention of water in aquifers and its subsequent use in drier or increased demand periods, MAR techniques were studied in 4 pilot areas in the DEEPWATER-CE project funded by the Interreg CENTRAL EUROPE program. Originating from transnational toolbox for designating potential MAR locations in Central Europe, the MAR pilot sites in the project participating countries were identified, namely in Hungary, Poland, Croatia and Slovakia. Slovak partner was designated to utilize the MAR methodology for agricultural purposes using as a source the surface water in channel system of the greatest lowland in Slovakia – the Rye Island (Žitný ostrov in Slovak language or Schüttinsel in German). The territory of the Rye Island is bordered by the Danube River from the West, the Váh River form the South-East and the Little Danube River from the North-East. The whole territory of the Rye Island is protected against flooding by flood protection dikes. To have the possibility to collect and dewater the surplus water from agricultural land after heavy rain or snowmelt the drainage channel system was built in the last century. The existing form was achieved in the second half of the century and it was completed after putting Gabčíkovo hydropower plant (GHPP) into operation in 1992 (Šoltész et al., 2021). The main objective for the Slovak side in frame of the project was to induce infiltration from surface water body created by surface water in drainage channel system (sometimes ground water on the surface) into aquifer. The groundwater recharge using MAR techniques was realized using one of the former drainage system (S VII) in chosen territory of the upper Rye Island. More detailed explanation and description of the water management is presented in the introduction.

ABSTRACT. Prediction of rainfall using physical models is a challenging task due to the complexity associated with the formation and occurrence of precipitation. This paper investigates the use of machine learning technique, namely random forest to predict next-day rainfall based on the values of several meteorological variables for the current day. The effectiveness of random forest to predict next-day rain has been investigated through application to a large data set of meteorological variables from Australia. The feature vector comprised of 23 meteorological variables that were used as input to the model. Since the dataset contains several missing values, feature engineering was employed to fill-in the missing values. About 70% of the data points were used to train the model and the remaining 30% were used to test the model on the unseen data. Various metrics, such as accuracy, precision, recall, and F1 score were used to evaluate the performance of the classification model. The model achieved an accuracy of 87%, indicating 87% of the instances in the dataset were correctly classified. The precision of the model was 82% indicating that out of all instances predicted as positive, 82% were actually positive. The model had a recall of 71%, which shows that the model has a low tendency to miss positive instances. A F-1 score of 0.76 was achieved, which indicates that the model was able to minimize false positives and false negatives to a significant extent. Given the high degree of complexity associated with the precipitation phenomenon, the performance of random forest in predicting the next-day rain can be considered as highly satisfactory. The methodology employed in this research is generic in nature, and can be utilized to predict next-day in different regions of the world. It can be concluded that accurate prediction of next-day rain using random forest can significantly enhance decision-making processes, improve water resource allocation, and contribute to sustainable development particularly under the influence of climate change.

ABSTRACT. The Southwest region of the United States, encompassing the states of California, Arizona, and New Mexico, produces hundreds of agricultural commodities, including many specialty crops such as almonds, grapes, tomatoes, and pecans, as well as forage and fiber crops like alfalfa and cotton. Yet, Southwest agriculture is extremely vulnerable to climate change and the climate-drivers of mismatches in agricultural water supply and demand. In order to assess the potential risk of Southwest agriculture to climate change, we quantified the projected climate exposure of select crops across the region. Shifts in crop phenology were modeled under two future climate scenarios using known crop-specific thresholds. Additionally, a suite of agriculturally-important climate metrics were evaluated over the contemporary and future periods, along with their trends. Analyses were conducted using 4-km gridded meteorological data over the contemporary period (1991-2020) and 4-km statistically downscaled climate data over the future period (2040-2069) under both RCP 4.5 and RCP 8.5. Results for California winegrapes, which we will highlight because of their high economic importance and large diversity in varieties, show that both geography and variety are important in understanding potential climate exposure. Cabernet Sauvignon generally has larger trends in phenological advancement than other varieties, but the magnitude of these trends varies by region. Results also show that vineyards across the state will see longer growing seasons, an increase in extreme heat exposure, and higher growing season evapotranspiration. From a water resources perspective, these climate changes will increase crop water demand and will necessitate adaptive management actions to best manage increased water demands in a water scarce region. As such, this presentation will also address science-backed adaptive management opportunities that can be adopted to increase the resilience of Southwest agriculture to increased water resources stress resulting from climate change.

ABSTRACT. Climate change poses significant challenges to water resources management and agricultural productivity, particularly in semi-arid regions that are dependent on irrigation for crop cultivation. This study focuses on the Pakhal Lake command area located in semi-arid region of Telangana, India, assessing the impact of climate change on irrigation water demand and proposing adaptation strategies to ensure sustainable water resource management. The primary objective of the study is to assess the impact of climate change on irrigation water demand and propose adaptation strategies for ensuring sustainable water resource management in the region. Using the CROPWAT model, the research aims to estimate Irrigation Water Requirements (IWR) for the Pakhal Lake command area under various climate change scenarios. The study anticipates a substantial increase in future irrigation needs based on eight distinct scenarios reflecting potential alterations in climate and cropping patterns. Notably, under S1, S7, and S8 scenarios, future irrigation demand is projected to increase by 8.9%, 16.7%, and 16.8%, respectively. Recognizing the practicality of S1 over the more speculative S7 and S8 scenarios, S1 was selected for developing the adaptation strategies and optimizing irrigation releases. To bridge the gap between water availability and demand and enhance water resilience, Stochastic Dynamic Programming (SDP) is employed to optimize irrigation tank management policies. Tank performance indices under Standard Operating Policy (SOP), SDP with and without adaptation, are thoroughly evaluated. The study identifies the combination of mixed cropping and delayed plantation as the optimal strategy, achieving high reliability (0.95), resilience (0.73), and low vulnerability (0.19). Although a combination of mixed cropping and increased irrigation efficiency yields the highest reliability (0.97), it compromises resilience (0.32). Consequently, the mixed cropping and delayed plantation combination is selected as the best-fit strategy due to its ability to achieve optimal performance indices. The study emphasizes the need for an in-depth analysis of current challenges faced by farmers and water managers, including changing precipitation patterns, rising temperatures, and competing water demands. Addressing these challenges requires a range of adaptation strategies, such as improved water storage, crop diversification, and water-use efficiency measures. SDP serves as a valuable tool for decision-makers to identify and implement effective adaptation strategies, ensuring sustainable water management practices amid climate change. The research provides insights to government and decision-makers in the Pakhal study area, guiding them in understanding climate change effects and modifying tank management policies to address fluctuations in water supply and future irrigation demand.

ABSTRACT. Although the water-food, or water-energy-food, nexus is an emerging theme within the geosciences and social sciences research communities, the accelerating water and food gaps, and the fact that they exacerbate each other in a vicious cycle, especially in arid regions, make the nexus studies a necessity, rather than a research luxury. Water resources availability and sustainability are critical components for economic development and growth. Therefore, effective management of agricultural water use, which is the major water consumer, is a national priority everywhere. In this study, cropping pattern planning is used as a major policy variable for agricultural water management in arid regions. We consider the case study of Egypt, as an example of arid climate, to showcase the inseparable nature of water and food security. We use a framework for the generation and assessment of alternative cropping pattern alternatives (ACPs), called ACPAR, with a simulation-based national water, food, and trade (NWFT) model. ACPAR is formulated to simultaneously minimize the national agricultural water demand, amounts of food (virtual water) imports, and the cost of imports, and to maximize the national gross margin of agriculture. These four objective functions are used to generate several non-dominated ACPs. The objective functions of the ACPs generated are evaluated using the NWFT model during the baseline period (1986-2013) as well as projected up to year 2050 under various combinations of national development and global food price scenarios. The results show that the ACPAR framework is useful for proposing policies (ACPs in our study) that could have improved Egypt’s performance during the baseline period and can be the basis for more resilient future. Tradeoffs between Egypt’s food self-sufficiency, the national water use, the revenue in the agriculture sector, and the cost of imports are quantified, which form the key contribution of this study, representing critical information for policy makers to aid in important decisions. The presented methodology connects the national water resource to the global food production, consumption, and trade dynamics. This study demonstrates that arid nations’ water management is sectorially intertwined with other sectors (e.g., food) and geographically linked to global dynamics. The output of IMPACT model (of the International Food Policy Research Institute) is used to connect Egypt with the global food market. Although NWFT model and ACPAR framework were developed for Egypt, they can be adapted to other arid regions and case studies. The methodology and results will be synthesized to propose a suitable water-food nexus framework for Saudi Arabia (and potentially other GCC countries) to guard its national food security in light of its limited renewable and non-renewable groundwater, its water desalinization potential, global food dynamics, and strategic regional food supply options.

ABSTRACT. Resource scarcity (labor, water, and energy) and high production costs are challenging the sustainability of conventional methods for rice establishment across the world. Traditional flooded rice (TPR) demands more chemical fertilizers, inviting pests and diseases. Water saving irrigation practices including direct seeded rice (DSR) is a potential alternative, resource saving establishment method. It offers a very exciting opportunity to improve water and environmental sustainability. It involves line sowing of dry seeds into a wet soil surface (wet seeding), or dry seeding into a prepared seedbed (dry seeding). The Tungabhadra irrigation command, N-Karnataka, India is continuously facing shortage of water, labor, and poor soil health (salinity). Results of series of field trials showed that cost economics was worked out in two ecosystems wherein, the net returns from DSR was 49,036 ha-1 which was much higher than TPR (44,091 ha-1) further it resulted in input output ratio of DSR was high (2.69) than TPR (2.13). In the event of a monsoon delay in the region or a water constraint, we demonstrated in large scale DSR allows the farmer to direct sow a paddy with an appropriate short-duration variety to fit within the cropping system. Availability of broad-spectrum selective herbicides in DSR weed management was found effective. Greenhouse gas emission (CH4, CO2 and N2O) in different crop establishments was analyzed which revealed methane produced from DSR was 2986.7 mg/day which differed significantly with TPR (4425.0 mg/day). The total reduction in methane gas in dry-DSR is 67.50 per cent compared to TPR. Results also exhibited greater irrigation water productivity and rainwater productivity over TPR. Farmers have realized that by following DSR method a net profit of 6000 Rs. /Acre with 37% of saving of irrigation water and 35% of methane gas emission can be saved. In labor-scarce areas, provided herbicides DSR technology offers a viable alternative to traditional rice production, demonstrating productivity, economic feasibility, and environmental sustainability.

ABSTRACT. Reverse osmosis (RO), as a water desalination process employing semi-permeable membranes, presents a promising solution to tackle the global issue of water scarcity. This study conducted experiments on a Reverse Osmosis (RO) plant integrated with photovoltaic (PV) panels at the LPHE-modelling and simulations laboratory, located within the Faculty of Sciences, Mohammed V University, Rabat, Morocco. The main objective was to assess water quality and its potential treatment by collecting samples from Ain El Atti, Errachidia, Morocco, where water quality testing revealed significantly elevated Total Dissolved Salts (TDS), rendering the water saline. In this work, we present a rigorous mathematical model of the RO process, based on the principles of diffusion and mass transfer of solution. The model's accuracy was validated by conducting a series of experiments in the pilot laboratory. Additionally, we investigated the impact of feed water temperature on critical thermodynamic parameters (TDS, flow rate (Q), Specific Energy Consumption (SEC), recovery rate (Y), and retention rate (TR)). Comparative analysis between the mathematical model and experimental data demonstrated a close alignment of over 85%, indicating the high validity and reliability of the mathematical predictions in agreement with the actual experimental results. This study sheds light on the potential of RO technology coupled with PV panels for water desalination and emphasizes the importance of considering environmental parameters, such as feed water temperature, in designing effective desalination systems.

ABSTRACT. The UAE is making progress in developing the Controlled Environment Agricultural (CEA) production system by adopting technologies like the Greenhouse and hydroponics. It is estimated that some 10,000 greenhouses and 1,000 hydroponic farms exist in the Abu Dhabi Emirate alone. These modern farming techniques aim to increase crop production using minimum inputs including irrigation water. The objectives of this study of hydroponic farms include analyzing water productivity and economic efficiency; and assessing impacts on energy and water consumption of the farms. This study is based on empirical farm-level data obtained from sample hydroponic farms. Farm economic analysis is rare in this field in the UAE. Hence, this study fills such a knowledge gap. The study focuses on the raft system and an NFT (Nutrient Film Technique) system type of hydroponics used to grow selected vegetable crops (cucumber, tomatoes, and lettuce) in the UAE. Primary data were collected from 36 private hydroponic farms in Abu Dhabi in Spring 2021. Most of the farms started operating in the last 7 years and by now have quite an experience in the management of hydroponic farms. The average greenhouse area for the sample farms is 4000 meters while the average number of greenhouse pans is 14. Profitability analysis of a typical sample hydroponic farm for a growing cycle or season shows a net profit per square meter of 2,692 Dirhams, 682 Dirhams, and 949 dirhams for tomatoes, cucumber, and capsicum enterprises, respectively. This is a significant improvement in farm productivity. Hydroponic farms use water for cooling the greenhouse using an evaporative system (pad and fans). Water consumption for greenhouse cooling is one major cost of hydroponic farms. A study made in the UAE (Fadel, 2014) found that farmers use much more amount of water for greenhouse cooling than what they need for crop irrigation. In the current study, the amount of water consumed for cooling a greenhouse was measured using a flowmeter installed at a few farms. Measurement made at one hydroponic farm over a time period of 246 days shows that the farm used 8.7 liters of water per square meter per day for cooling a greenhouse. This implies a consumption of 9.24 cubic meters of water for cooling a greenhouse of 1040 sqm area. The result of this study has significant implications for investment decisions and production management in the hydroponic farms sector.

ABSTRACT. Launched by Living Planet Morocco in 2019, the Sebou Water Fund (SWF) stands as a groundbreaking initiative devoted to tackling the imminent challenges posed by water scarcity and sustainability within semi-arid and arid regions. SWF's principal research objective is to formulate an integrated and adaptable model for water resource management that can serve as a global benchmark. A core focus of SWF centers on the rejuvenation of degraded ecosystems within the Sebou Basin. Through extensive efforts in wetland preservation and restoration, reforestation, and the promotion of sustainable land management practices, SWF seeks to enhance the natural capital of the region and bolster its resilience in the face of water-related adversities. SWF deeply acknowledges the pivotal role that local communities play in ensuring sustainable water management. By actively engaging with these communities and implementing projects designed to improve livelihoods, SWF fosters a profound sense of ownership and responsibility among residents. This engagement is critical for ensuring the long-term success and sustainability of water conservation endeavors. Currently, SWF serves as a proactive partner to governmental entities, actively contributing to the enhancement of water-related policies and regulations. Through tireless advocacy for environmentally sound practices and the assurance that legal frameworks align with the pursuit of water security, SWF helps create an enabling environment for sustainable water management practices. SWF's operations rely heavily on data collection and analysis, aimed at pinpointing opportunities for optimizing the allocation of water resources. This includes the assessment of the value of ecosystem services, an in-depth understanding of water supply and demand dynamics, and the implementation of strategies geared toward efficient resource allocation. SWF's endeavors have yielded remarkable results since its inception. To date, it has successfully restored approximately 1,500 hectares of land in the Atlas Cedar Biosphere Reserve, with ongoing efforts to restore an additional 125,000 hectares in the Ifrane National Park. This significant ecological restoration has had a profound positive impact on the well-being of approximately 10,000 local inhabitants. In addition, SWF has played an instrumental role in the fortification of policies and regulations. Its advocacy efforts have been pivotal in the implementation of environmental flow (law 36-15), thereby providing added protection to the Sebou Basin's precious water resources. Through these diverse interventions, SWF has successfully assessed the economic value of water-related ecosystem services in the Sebou Basin, revealing an annual worth approaching 3 billion USD. The predominant portion of this value is attributed to the agricultural sector, underlining the critical necessity of sustainable water management practices within this basin. SWF's remarkable achievements carry far-reaching implications for global water sustainability endeavors. In an era marked by escalating water challenges, particularly within MENA region, SWF's holistic and replicable model offers a compelling blueprint for integrated water management. Its success underscores the viability of combining ecosystem restoration, community engagement, policy advocacy, and sustainable resource allocation to bolster water security and champion the sustainable utilization of water resources. SWF stands as an inspiring exemplar for regions worldwide grappling with water-related predicaments while striving to promote both environmental and socio-economic growth.

ABSTRACT. The southern Mediterranean region, including Tunisia, faces significant challenges related to limited and irregular water resources, exacerbated by climate change. Agriculture, a crucial sector representing over 80% of water consumption in North Africa, is particularly vulnerable to water availability and quality. Meeting the increasing demand for food production, projected to double by 2050, further intensifies these challenges. To address water scarcity, especially in the next 30 years, it is crucial to implement effective water management solutions. In Tunisia, where water scarcity is a pressing issue, tapping into unconventional water sources like treated wastewater and desalinated water becomes imperative. These sources can play a pivotal role in bridging the gap between water availability and agricultural needs, ensuring a consistent water supply throughout the year. In response to these challenges, collaborative efforts within the framework of various Research and Innovation projects, have been undertaken. The objective is to develop innovative and context-specific solutions for the management of non-conventional water resources. Special attention was given to the technical, economic, social, and regulatory aspects, ensuring comprehensive solutions and effective outcomes. Low cost and energy efficient solutions for urban and industrial wastewater treatment have been developed. Demonstration pilots have been implemented in industrial and urban wastewater treatment plants. The treated wastewater has been successfully tested for field irrigation, yielding comparable results to traditional irrigation with drinking water, without adverse effects on plants or soil. Additionally, innovative desalination systems, incorporating nanofiltration and reverse osmosis, have been developed. These systems significantly reduce energy requirements and improve the recovery rate of desalinated water. Notably, these systems are powered by photovoltaic panels, aligning with sustainable energy practices. To ensure the adoption of wastewater and brackish water treatment systems, various measures have been implemented, with a focus on end-user acceptance. Replicability is emphasized, and recent examples demonstrate the successful implementation of these technological solutions. Efforts are made for the replicability of these technological solutions as evidenced by recent examples.

ABSTRACT. The objective of this study was to evaluate the influence of saline levels in the root zone on crop productivity and economic viability in the Central Valley. A comprehensive biophysical model was developed by integrating several factors, including soil variables, climate conditions, irrigation inputs, and economic data. The study examined four primary crops: alfalfa, almonds, table grapes, and processed tomatoes. The study investigated the effects of five different irrigation water salinity levels, ranging from 0.5 to 5.5 dS/m, as well as varying daily irrigation water quantities, ranging from 0 to 12 mm. The findings of the study demonstrate the model's robust predictive powers, as evidenced by the R2 values obtained for the anticipated yields of alfalfa, almonds, grapes, and tomatoes, which were 0.82, 0.77, 0.78, and 0.64, respectively. The root mean square error (RMSE) values for the same crops were 9%, 8%, 23%, and 11%, respectively. Predicted profits for alfalfa, almonds, and processing tomatoes exhibited a high R2 value of 0.99, indicating a strong correlation between simulated and actual profits. However, the R2 value for grapes was 0.74, suggesting a relatively weaker relationship between the predicted and actual profits for this particular crop. The RMSE values for the crops of alfalfa, almonds, grapes, and processing tomatoes were recorded as 48, 211, 2461, and 68 $/ha, respectively. In addition, the model integrated a geographical element, uncovering disparities in crop yield and profitability attributed to changes in soil composition and levels of groundwater salinity throughout the Central Valley. The findings of the study revealed that when daily irrigation rates were set at 3 mm, none of the crops would provide any revenues, while a daily irrigation rate of 6 mm resulted in profits of up to $1000 per hectare for crops such as alfalfa and processing tomatoes. Furthermore, in the case of almonds and grapes, a higher irrigation rate of more than 8 mm per day was necessary to attain profitable outcomes. Utilizing this comprehensive modeling approach offers policymakers valuable insights into discerning regions not conducive to sustainable and financially viable irrigated agriculture. This approach has the potential to assist in the prioritization of sites suitable for multi-benefit land repurposing, so contributing to the reduction of agricultural water demand and the achievement of groundwater sustainability. Additionally, the model functions as a decision-support tool for farmers in arid regions, allowing them to predict reductions in crop yield and profitability resulting from increased salinity levels in irrigation water.

ABSTRACT. Global urbanization has altered urban land use patterns and subsequently impacted hydrological processes. Urban impermeable surfaces, such as pavement and concrete, have the capacity to accumulate approximately 66% of rainfall. This accumulation leads to an elevated volume of stormwater flow, which constitutes a significant nonpoint source of pollution. The main types of contaminants present in stormwater runoff are petroleum hydrocarbons, metals, nutrients, and sediments. This situation is exacerbated in arid regions where rainfall is scarce and often associated with the phenomenon of first flush that carries shock loads of contaminants accumulated during a dry period. In this paper, a statistical meta-data analysis was conducted to assess pollutant concentrations and variability in arid regions. The analysis utilized 43 publications from multiple databases, including ScienceDirect, ResearchGate, and Google Scholar, among others. From the analysis, there was a notable abundance of total suspended solids (TSS) as the primary sediment, with a peak concentration of 192 mg/l. Contrarily, limited presence of nitrogen compounds was observed, and this may be attributed to limited agricultural activities. The detected heavy metals are aluminum (Al), manganese (Mn), chromium (Cr), vanadium (V), barium (Ba), iron (Fe), zinc (Zn), titanium (Ti), and nickel (Ni), with concentrations ranging from 0.23 – 122 mg/l. Total organic carbon (TOC) and chemical oxygen demand (COD) were found at high concentrations of 40.7 mg/l and 30.71 mg/l, respectively, possibly originating from fecal matter and industrial effluent found in these areas. For residential areas, it was found that the presence of polycyclic aromatic hydrocarbons (PAHs) was detected at concentrations reaching 35.7mg/l due to the risk of oil spills caused by vehicular traffic. These findings will aid in the development of strategies to address and mitigate the presence of the identified pollutants, ultimately contributing to a safer environment.

ABSTRACT. This paper introduces a novel Ceramic Membrane-based Produced Water Treatment Technology (CMPWT) and demonstrates its effectiveness in treating a carwash water sample obtained from Al-Ain, located in the Abu Dhabi Emirate, United Arab Emirates. The carwash sample was acquired in May 2023 from a local car washing facility in Al-Ain city. Employing a dead-end filtration mode with a filtration rate of 3 m3/m2/d, the transmembrane pressure peaked at approximately 30 kPa (temperature adjusted to 25oC). To alleviate the pressure, air blowing was employed, resulting in a reduction to around 5 kPa. In a span of one hour, the Total Suspended Solids (TSS) in the water were remarkably decreased from an initial 489 mg/L to a final concentration of 2 mg/L. The water chemistry analysis revealed a Cl-HOC3-Na-Ca composition for the carwash wastewater. This investigation highlights the capability of CMPWT in efficiently reducing TSS in carwash wastewater. The treated water can be safely discharged into the environment without causing harm or can be reused within the same facility.

ABSTRACT. Cationic dyes in textile wastewater are harmful as they can disrupt aquatic ecosystems, hinder the self-purification capacity of water bodies, and pose health risks. Their removal is crucial to prevent water pollution, protect aquatic life, ensure safe drinking water, and to promote environmental and human well-being. stands out as an effective method to remove cationic dyes from. Electrocoagulation involves passing an electric current through the wastewater, causing metal electrodes to release ions that neutralize and coagulate the dye molecules. This forms flocs that can be easily separated. Electrocoagulation is efficient and environmentally friendly, as it doesn't require the addition of chemical coagulants. However, it can be energy-intensive, especially for large-scale applications. The present work deals with effective use of raw Bentonite clay (RBC) to improve electrocoagulation treatment efficiency of synthetic effluent containing Brilliant Green (BG) dye. Raw Bentonite clay has been used for adsorption as well as coagulant aid during electrocoagulation process to reduce the treatment time which results in less energy requirement. Electrocoagulation coupled with adsorption experiments were carried out in a batch scale stirred reactor with aluminum electrodes. Locally Collected RBC was used directly in raw form without any treatment and was characterized by EDS (Energy Dispersive X-ray Spectroscopy) and FTIR (Fourier Transform Infrared Spectroscopy) analysis. At initial stage, different dosage of RBC was added to synthetic wastewater containing BG dye to obtain adsorption efficiency of RBC. Further, potential of RBC as coagulant aid during Electrocoagulation process was observed and effects of parameters such as clay dose, current density and pH were studied. Effect of RBC addition on electrical energy consumption, settling time and quality of sludge was also evaluated. Results revealed that at low RBC dosages, BG adsorption on RBC was not as effective. Adsorption became significant at dosages higher than 0.08 g/l. Moreover, remarkable increase of ~55% in color removal was observed with addition of RBC into electrocoagulation. Addition of RBC caused the netting and bridging of flocs and enlarged the frame and weight of the network produced by electrocoagulation. Settling velocity of sludge was higher in presence of RBC compared to only electrocoagulation process. Thus, it is found that RBC performed as a coagulant aid as well as an adsorbent.

ABSTRACT. The growing demands of UAE ‘s water needs are directly affecting the energy requirements of the region as well .It is high time to explore methods and measures that result in the provision of energy smart water sources .The potential of grey water as a re-utilized source of water has shown prospective results across the globe .Grey water is a less utilized resource having immense potential for recycling and thus contributing to circular economy .The meagre energy demand of reusing the grey water for multiple uses makes it an attractive source in an arid country like UAE. The instances from across the world from countries like Israel and other developed countries who lead the research in grey water show that there is a promising niche for grey water to grow out as a “neo source” for multiple purposes from flushing in multi storeyed high-rise buildings to incredible uses including potability. In this research, utility of grey water in irrigating the fodder crops of UAE is being attempted. While we plan means to achieve self-sufficiency over dairy production, effective ways to be worked out for conserving the water use for per capita fodder production too.

Therefore, most common fodder crops cultivated in UAE were identified and seeds were collected from the farms of UAE. Nine different varieties were grown in green house in pots as 5 major experimental blocks utilizing two treatments of different irrigation. The outlet grey water is collected from a food production factory located in Ajman ,UAE.The use of liquid chemicals containing surfactants and chemicals are mostly used for vegetable and handwashing purposes in this factory .The experiment is planned so as to get the three best performing varieties of fodder crops from the green house as a first phase .The second phase emphasizes the location specific accumulation of heavy metals ,viz-where in the plant, which profile of the soil or in the outlet water . In the first stage, samples of water and soil are selected for finding a set of parameters contributing to the performance of each variety. The samples grey water, both filtered and unfiltered, show slight difference in Total Nitrogen content ,5.6 and 4.48 mg/L respectively. The parameters like heavy metals, EC, pH, BOD, COD, TSS and other factors of relevance were analyzed. The vigor of the plants is the best observed in the blocks irrigated by grey water than in normal tap water. The preliminary stage of the experiment itself shows promising results that could be added as a benchmark or breakthrough in the water research sector which can ultimately contribute tangible reduction in the consumption of water other than for potable purpose in the UAE.

ABSTRACT. Optimal Location for Installing Energy Recovery System in TRANSCO Water Transmission System 1 Aamna Al Mazrouei , 2 Dr. Andrei Sleptchenko, 3 Dr.Mohammed Abdallah 1 Management Science and Engineering Department, College of Engineering, Khalifa University, TRANSCO, Abu Dhabi, UAE. Email: 100057737@ku.ac.ae 2 Management Science and Engineering Department, College of Engineering, Khalifa University, Abu Dhabi 3 Emirates Water and Electricity Company (EWEC), Abu Dhabi

Abstract Energy Recovery in the water sector is an area that has gained researchers' focus in recent years. There is a vast energy loss in the water distribution system WDS in which 40% of the energy is wasted through head losses in pipes and valves. The potential hydropower energy is embodied in water systems which can be recovered to compensate for electricity consumption. This energy can be captured to be reused in the local grid. The network system is a high-energy system where dissipation valves regularly lower water pressure to control the pressure inside the pipes and prevent leakage. The dissipation generated by the valves can be recovered to produce energy. One solution to achieve Energy recovery in WDS is to replace dissipation valves (pressure-reducing valve PRV) with hydropower turbines. However, such networks are complex, and finding the best location to install turbines for energy harvesting is difficult. This study discusses the literature on the potential of energy recovery in the WDS, current industry technologies for energy harvesting, and the optimization methodologies literature to find the optimal location to install an energy recovery system. This study studies a case study for a water network and estimates the potential of energy recovery, a methodology proposed using optimization techniques to find the best location to install a turbine. The simulation and validation of the energy harvesting solution in a WDN have been done using EPANET hydraulic solver in multiple case studies in Transco. Applications: In the TRANSCO water supply system, substantial excess energy, and energy recovery potential need to be examined in potential locations. In addition, many sites require to be studied to install energy recovery technology. Technical contributions: Currently, Similar studies have been done in different regions of the world to examine the excess energy in the system initially and install turbines to harvest this energy. However, no such study happened in the UAE and the water piping system in the UAE region, especially in TRANSCO. Results and conclusions: This paper proposed a methodology to find the optimal location to install a hydropower turbine. The optimization model is developed consisting of the objective function to maximize the produced energy by the turbine. A case study consists of a water supply source supplying three customer nodes by valves. The model is designed to replace each PRV with a GPV (turbine) and compute the energy produced. The case study shows that the maximum energy was obtained at valve 15 with an amount of 38.936 kWh.

ABSTRACT. The various treatment for purifying the contaminated dye solution, the photocatalyst is a potential method because it is simple and environment friendly and it does not generate any toxic byproducts while degrading the dye solution. In the present work, synthesized CdSe quantum dots (QDs) decorated ternary metal oxide nanocomposite of ZnO/TiO2/CuO through the simple hydrothermal method. The as prepared nanocomposite exhibits the monoclinic, hexagonal and cubic phase structures in XRD (X-ray Diffraction) analysis. UV-Vis absorbance spectra show the broad absorption spectrum and SEM (scanning electron microscopy) clearly shows the presence of nanoparticles and confirmed elements through elemental mapping. TEM (Transmission Electron Microscopy) confirms the nanostructure of metal oxides decorated with QDs. The average particle size is 45 nm for metal oxides and 7nm for QDs. XPS (X-ray photoelectron spectroscopy) also confirms the surface elemental composition. The prepared nanocomposites were introduced as photocatalyst for industrial dye solution among the samples CdSe@CuO/TiO2/ZnO for shows 96% of photocatalytic degradation efficiency. It found a recycling efficiency of ~92% after 4 cycles against methylene blue (MB) organic dye under visible light irradiation.

ABSTRACT. Introduction. With the growing global population, there is an increased demand for high-quality food, including animal-based products. Some of these products come from aquaculture, as of 2020 this activity has matched production from capture at sea and is expected to overtake it with a production of up to 100 million tons within the next ten years. In Mexico, as well as the rest of the world, one major species for production is shrimp. However, one concern is feeding these species, as many desirable ingredients for this purpose have inflated costs, for which the use of insects could provide an attractive solution. Black soldier fly larvae have proven to be a suitable option to meet many animals’ nutritional requirements and have thus been chosen for this project. Materials and methods. Four ingredients were selected for the design of the balanced feed: Nixtamalized Corn Meal (CM), Soybean Meal (SBM), Fish Meal (FM), and Black Soldier Fly Larvae Meal (BSF). CM and SBM were kept at 36% and 20%, respectively, while FM and BSF were included at an FM/BSF ratio of 0/44, 11/33, 22/22, 33/11, and 44/0, according to the experimental design. Extrusion parameters were chosen as 14% moisture content of the sample, single-screw extruder, 180 rpm, and a final heating zone temperature of 120, 128, 135, 143, and 150 ºC. The resulting extruded products were evaluated on the following physical properties: Expansion index (EI), Bulk density (BD), Hardness, Water absorption index (WAI), Water solubility index (WSI), and Oil absorption index (OAI). Results. EI: EI was observed to increase with higher temperatures and BSF inclusion, however, no significant differences were observed for similar treatments. BD: Temperature was observed not to have a significant effect on BD, whereas BSF inclusion was observed to have it. Hardness: BSF inclusion was observed to have a significant effect on Hardness, with its highest inclusion producing the frailest structures. WAI & WSI: At lower temperatures, WAI was observed to decrease with higher BSF inclusion, whereas WSI was observed to increase with it. This was attributed to the high-fat content of BSF hindering the correct gelatinisation of CM’s starch, as well as acting as a lubricant to reduce pressure build-up at the exit die, both effects resulting in extruded products of poor water stability. OAI: There were no significant differences for measured OAIs, this was also attributed to the high-fat content of the ingredients used, however, the high protein content is assumed to also have an effect, as non-poplar amino acids interfere with the oil entrapment mechanism of the extruded products. Conclusions. – BSF meal is suitable for the production of extruded feed. – It is possible to replace FM content in extruded feed using BSF meal, however, exclusive use of BSF meal can result in extruded products of poor structural integrity and water stability. – This may be caused by the BSF meal's high-fat content having a negative effect on certain physical properties like WAI and OAI.

ABSTRACT. The United Arab Emirates (UAE) has undergone significant and transformative changes, marked by extensive government initiatives aimed at fostering well-urbanized regions. Since the UAE's national reunion in 1972, Abu Dhabi, the capital emirate, has been at the forefront of this development surge, experiencing rapid urbanization across its landscape. As part of this dynamic transformation, numerous islands have been rehabilitated, serving diverse functions, including industrial, residential, and tourism development. Among these, Al Saadiyat Island stands as a prime example of intense urbanization in the region. This research endeavor is driven by the pressing need to comprehend the intricate interplay between extensive urban development, the fragile coastal ecosystem, and marine and sub-marine life. It underscores the critical importance of informed decision-making to foster sustainable coastal management practices. Given the high dynamism of the area and the limited evaluation of its shoreline, the long-term utilization of geospatial technologies is deemed essential and productive. Therefore, assessing high urbanization becomes a substantial task to promote sustainable development. The primary objectives of this study encompass evaluating the extent of shoreline alterations resulting from urbanization, including activities such as land reclamation, construction, and infrastructure development. Additionally, we aim to identify potential pollution sources linked to urbanization and assess their influence on the shoreline ecosystem. Furthermore, we seek to gauge the effectiveness of existing coastal protection measures, all of which contribute to the development of a geo-model capable of predicting the future evolution of the shoreline in response to ongoing and prospective urbanization activities. To achieve these goals, geospatial technology in conjunction with in-situ measurements through the analysis of remote sensing imagery and the utilization of Geographic Information Systems (GIS) were utilized. The study offers insights applicable to urbanized coastal regions, highlighting shoreline alterations and their connection to urbanization. Pollution from urban development impacts water quality, underscoring the need for sustainability. The variable effectiveness of coastal protection measures calls for adaptive strategies due to changing coastal dynamics driven by urbanization. The development of the geo-model represents a pivotal outcome of this study, offering a valuable tool for decision-makers. It enables them to anticipate and manage shoreline changes in diverse urbanized environments, thereby facilitating sustainable development efforts on a global scale. Overall, this study serves as a critical resource for informed decision-making aimed at achieving a subtle balance between urban growth and environmental preservation in coastal regions. It underscores the urgency of embracing sustainable practices and harnessing advanced technology to navigate the complex challenges posed by urbanization.

ABSTRACT. The significance of groundwater in a water-scarce country such as United Arab of Emirates, characterized by a lack of permanent surface water sources, cannot be overemphasized. The effective implementation of sustainable and long-term development strategies relies on a thorough understanding of water resources. To evaluate the water resources, it is crucial to assess the groundwater by conventional or technologically advanced approaches. The evaluation of aquifer characterization along with the groundwater modeling, is greatly dependent on the rock properties, such as its hydraulic conductivity and transmissivity. Surface geophysical techniques, specifically electrical resistivity measurements, have proven to be highly valuable and extensively utilized in the identification of sub-surface aquifer parameters. These parameters encompass rock type, saturation degree, groundwater depth, extension, and other sub-surface properties that are directly associated with the aquifer properties. The approach is characterized by its rapidity, cost-effectiveness, and widespread utilization in various shallow contexts. The present study aims to characterize the alluvial Quaternary aquifer in the Falaj Hazaa of Al-Ain city, and then estimates the principal aquifer’s hydraulic parameters based on the interpreted Electric Resistivity Tomography (ERT) and Vertical Electrical Sounding (VES) methods at different times during this study. For that, Four Vertical Electrical Soundings (VES’s) and eight ERT profiles utilizing a Wenner array configuration is performed to identify and estimate the subsurface resistivity distribution along the surveyed profiles, indicating the water-bearing formation, thickness, hydraulic conductivity, and transmissivity parameters along the measured longitudinal profile from the interpreted VES data. A comparison was then made between the transmissivity values obtained from the VES models and the prior pumping test measurements conducted in the region, revealing a notable correlation between the two datasets. The estimated transmissivity of the aquifer is about 100 m3/d and the hydraulic conductivity is 5 m/d. The main water level of the saturated zone is found at a depth of 10 m but can extend deeper, reaching depths of 25 m and beyond. The findings suggest that the utilization of surface geoelectrical resistivity techniques could serve as a viable and efficient approach for predicting aquifer hydraulic characteristics in situations where pumping data is scarce or inaccessible.

ABSTRACT. In arid regions like the United Arab Emirates (UAE), the rise in global temperature and climate change has significantly impacted our ecosystems. This study aims to investigate the impacts of elevated temperatures on seed germination followed by early plant morphology and physiology with a focus on native Fabaceae plants in the UAE. The significance of this study ranges to both ecological and conservation standpoints, contributing to an insight into the susceptibility of native plant species to rapid changing climate conditions. As the UAE’s ecosystems faces rising temperatures, understanding the adaptive capabilities of native flora becomes vital for sustainable conservation studies. Prosopis sinnaria, Tephrosia nubica, and Senna italica are all plant species that belong to the Fabaceae family and are known to be native plants to the UAE with unique cultural, medicinal, and economical properties. The objectives of this research are to have a better understanding on the impacts of elevated temperature on the germination of dormant seeds as well as the changes that occur on early stages of plant growth. Germination parameters (Final germination percentage (G), Mean germination time (MGT), Mean germination rate (MGR), Coefficient of velocity of germination (CVG), Germination rate index (GRI), and Germination index (GI) ) and different plant morphology (biomass, root\shoot ratio, number of leaves) and physiology (chlorophyll content, sugar\starch content) were measured under 4 levels of temperature, using controlled growth chambers (T1:35°,T2: 40°,T3:45°,T4: 50° C) in comparison to greenhouse conditions. Our findings suggest that the seed germination parameters were improved in (T1) and (T2) levels, and significant changes started to appear in the highest level (T4). The young seedling performance did not show significant changes in T1 and T2 levels, however it declined at T3 and T4 levels.

ABSTRACT. A major cost encountered in treating wastewater is the power consumption during the aeration process of the activated sludge system. Aeration is achieved either by surface fans or by bottom diffusers. The bottom diffusers are usually found to be more economical to use. However, the low efficiency of conventional diffusers requires huge quantities of air to achieve the required treatment level. Therefore, it is necessary to improve the use of pumped air in the aeration tanks of activated sludge systems in order to decrease energy consumption as well as the process' carbon footprint. Fine bubble aeration provides advantageous aeration efficiency (more effective at transferring oxygen than a conventional system). More specifically, the energy consumption efficiencies are better than conventional aeration systems. In addition, they have a higher surface area/volume ratio as compared to conventional aeration and they tend to reside longer before they burst on the liquid surface. The use of fine bubbles for wastewater treatment containing pharmaceuticals such as caffeine was examined. A series of laboratory batch experiments were conducted to assess the use of air fine bubbles in treating pharmaceutical wastewater containing caffeine. In addition, another set of experiments was conducted using conventional air bubbles. The efficiency of the removal was compared in the two aeration systems. Moreover, the enhancement in parameters such as dissolved oxygen was evaluated. It was found that fine bubble aeration showed better removal results than conventional aeration. In addition, the dissolved oxygen content was enhanced using fine bubble aeration. It can be concluded that fine bubble aeration proved to have higher performance than conventional aeration which will have potential in wastewater treatment.

ABSTRACT. Industrial development and pollution are both sides of the single coin. Therefore, it is critical to create innovative technologies to reduce the harmful emissions from industrial growth and transform them into renewable energy sources. The proper treatment and disposal of industrial wastes in environmental resources is still a significant concern. It is an urgent need for safe drinking water due to the increasing number of people worldwide. present study, the different colored Mg (OH)2/Cu2(OH)3NO3 nanocomposites were prepared by the facile co-precipitation method. The prepared white Mg (OH)2 (MH), pale blue (MC-1), dark brown (MC-2), and dim grey (MC-3) colored Mg (OH)2/Cu2(OH)3NO3 nanocomposites were analyzed by different characterization techniques. The XRD and FTIR analyses confirms the phase and functional groups of the nanocomposites. The optical properties were analyzed via UV-DRS and PL; the band gaps (Eg) of MH, MC-1, MC-2 and MC-3 were estimated to be 4.19, 3.2, 3.27 and 3.34 eV, respectively. The morphology characterization demonstrates the slice-like nanosheet, and nanoflakes structures of nanocomposites as revealed by FE-SEM and HR-TEM studies. The prepared samples underwent photodegradation of rhodamine B (RhB) and methyl orange (MO) dyes under halogen 500 W UV-Visible light. The colors of the prepared catalyst help to increase the light absorption of the catalyst, which leads to larger and more oxygen vacancies and facilitates the easier and faster formation of electron-hole pairs in the photocatalytic process, thus increasing the photocatalytic efficiency. The prepared MC-1 catalyst achieved the higher (92% for RhB and 95% for MO) photodegradation than other samples due to the large surface oxygen vacancies of MC-1. The Z-scheme photocatalytic charge transfer mechanism of Mg(OH)2/Cu2(OH)3NO3 nanocomposites was confirmed by scavenger activity. A novel light pale blue Mg(OH)2/Cu2(OH)3NO3 nanocomposite may be a desirable alternative and highly effective photocatalyst for the degradation of a variety of organic dyes and wastewater treatment due to its low cost and scalability.

ABSTRACT. The extraction of oil in Oman results in a large amount of water coming out of the oil, which is then removed from the oil. This extracted water by-product, depending on the geology of the region, may contain petroleum by-products, heavy elements, radioactive materials, salts/sodium, and other cations such as potassium and calcium. The industry term, "Produced Water" (PW), will be used in this thesis to refer to the water extracted with the oil in the Nimr oil field after it has been passed through a living bed of reeds. PW is evaporated naturally after passing through a constructed of reed grass in the evaporation ponds. PW can be reused to irrigate crops and plants, and this will create environmental, and economic value. There are limited possible uses of treated water but possible solutions can enhance sustainability. Arid areas like Oman have been seeking salt-tolerant plants that can use saline water to save freshwater resources and maximize farm plants' yield. Therefore, this study aims to evaluate possible solutions and applications of using oil field PW on various plants. The present study evaluated the performance of various species irrigated under different water to determine plant survival and mineral uptake from two sites. The treatment was established in the Nimr site by using produced water from Nimr Wetlands output with total dissolved solids (TDS) of about 6500-7000 mg/L compared to well water with TDS of about 3000 mg/L. The second experiment at Sultan Qaboos University on the agricultural experiment station site used produced water, well farm well water with TDS of 825 mg/L, and treated municipal wastewater with TDS of 895 mg/L. Both experiments used control and Nimr soil to compare the two soil types and used gypsum and biochar as soil additions at the SQU site. Three harvests were obtained from the SQU site and five from the Nimr site. The results showed that the use of produced water in both experiments has increased the boron levels and cation (Na, K, Ca, Mg) concentrations in both soil and plant leaves and roots. The analysis showed a significant increase in most of the minerals with final harvest in both experiments with the use of produced water. Biochar and gypsum did not have a significant effect on plants' metal or nutrient concentrations. Soil addition of biochar showed a reduction in boron concentration in soil. Plants irrigated from produced water showed decreased leaf growth and more rapid plant death. The use of produced water resulted in higher levels of soluble salt, especially sodium levels in soils which resulted in soil degradation.

ABSTRACT. Continuous development of industrialization and urbanization has causes the tremendous energy and environmental quality crisis over the last few decades. Several researches are focusing on development of eco-friendly processes for energy and environmental redmediation. In the line of several research approaches, Photocatalysis having the considerable attention in both energy and environmental remediation applications which includes organic/inorganic pollutant removal from water resources, antibacterial activity, solar fuels (H2/H2O2) production, fuel conversions and air pollution controls. After the invention of photocatalysis process, several semiconducting inorganic/organic materials have been used as a catalyst for various energy and environmental based applications. Among the all materials, TiO2 and ZnO are still gaining the attention due to its suitable band structure and their physio-chemical behaviour. However, the utilization of these materials are become bottle-neck due to their higher bandgap and low photon absorption capacity. In recent years, organic semiconducting materials are considering as a potential photocatalysts due to their electron transport behaviour, higher light absorption capacity, and surface to volume ratio of the materials. Among that graphitic carbon nitride (g-C3N4) is receiving attention as an efficient catalyst for energy and environmental remediation applications because of the mediate bandgap, facile preparation, structural change flexibility and two dimensional natures. In this work, we have prepared the g-C3N4 photocatalyst with N-vacancy in the triazine unit through the high temperature treatment process. The presence of triazine unit N-vacancy was confirmed through powder X-ray diffraction, UV-Vis absorption spectrum and X-ray photoelectron spectroscopy. The N-vacancy in the g-C3N4 network is not only produce the intermediate band structure but also has altered the electronic band potential of the material. With this peculiar behaviour, the prepared g-C3N4 act as an efficiency photocatalyst for wastewater treatment and solar H2O2 production under visible-light irradiation. The improvement of the photocatalysis reaction is reveals the presence of intermediate band reduces the charge carriers’ recombination and alter the band potential for the favourable photo-redox reactions. Hence, this facile approach of g-C3N4 with N-vacancy can create a new path for the improved photocatalytic reactions for energy and environmental remediation.

ABSTRACT. In this study, 47 actinobacterial isolates were obtained from rhizosphere soils of royal poinciana in the United Arab Emirates (UAE). Three Streptomyces strains exhibited powerful in vitro antifungal activity against Neoscytalidium dimidiatum (the causal agent of stem canker disease of royal poinciana). The antifungal action of Streptomyces rochei UAE2 and Streptomyces coelicoflavus UAE1 was mainly correlated with antibiosis and cell-wall-degrading enzymes production, respectively. Streptomyces antibioticus UAE1 was, however, associated with both mode of actions. These isolates suppressed lesion development on fruits inoculated with N. dimidiatum in the apple fruit bioassay. Under greenhouse conditions, individual biocontrol agents (BCAs) showed greater efficacies against stem canker when applied before N. dimidiatum than after the pathogen. The curative effects of Cidely® Top (a chemical fungicide) and S. antibioticus UAE1 on disease symptoms were comparable on royal poinciana. Prior to pathogen inoculation, S. antibioticus UAE1 was capable to suppress disease symptoms and prevent the pathogen spread, suggesting a relative superiority of S. antibioticus UAE1 over all other tested treatments. This was evident in the significant (P < 0.05) reduction in the number of defoliated leaves and conidia counts of N. dimidiatum in S. antibioticus UAE1-treated seedlings compared to the other two BCA or chemical treatments. In conclusion, the multiple mode of actions in S. antibioticus UAE1 can be particularly effective to produce synergistic actions against the fungus. This study is the first to explore the potential to use both biocontrol and fungicides to further develop integrated disease management against stem canker in royal poinciana.

ABSTRACT. In semi-arid and arid zones of the Mediterranean region, coastal wetlands deliver a wide range of valuable ecosystem goods and services. These ecosystems, that are often maintained by direct or indirect groundwater supplies, are collectively known as groundwater-dependent ecosystems (GDEs). The importance of groundwater supplies is greatly exacerbated in coastal Mediterranean regions where the lack of surface water and the over-development of anthropogenic activities critically threaten the sustainability of coastal GDEs and associated ecosystem services. Yet, coastal GDEs generally do not benefit from a legal or managerial recognition to take into account their specificity. Particular attention should be paid to the characterization of environmental and ecological water requirements. The hydrogeological knowledge about the management and behavior of coastal aquifers and GDEs must be strengthened. These investigations must be supplemented by a stronger assessment of potential contaminations to develop local land-uses and human activities according to the groundwater vulnerability. The quantitative management of water resources must also be better supervised and/or more constrained in order to ensure the water needs necessary to maintain coastal GDEs. The transdisciplinary approach, we propose here and based on case studies from Corsica, France, Italy, Tunisia, Algeria, Morocco, between hydrogeology, isotope hydrology, and social sciences is essential to fully understand the socio-economic and environmental complexity of coastal GDEs. We highlight that priority must now be given to the development of an appropriate definition of coastal GDEs, based on a consensus between scientists and water managers. It is a necessary first step to develop and implement specific protective legislation and to define an appropriate management scale. The investment and collaboration of local water users, stakeholders and decision-makers need to be strengthened through actions to favor exchanges and discussions. All water resources in the coastal areas should be managed collectively and strategically, in order to maximize use efficiency, reduce water use conflicts and avoid over-exploitation. It is also important to continue to raise public awareness of coastal aquifers at the regional level and to integrate their specificities into coastal zone management strategies and plans. In the global context of unprecedented anthropogenic pressures, hydro-food crises and climate change, environmental protection and preservation of coastal GDEs represents a major challenge for the sustainable socio-economic and environmental development of Mediterranean coastal zones.

ABSTRACT. Access to water is a prerequisite to achieving sustainable development and this is clearly stated in the United Nations Sustainable Development Goal (SDG) number six. However, different regions around the world such as the Sahel are still lagging far behind as far as meeting SDG goal number 6 is concerned. The Sahel is one of the regions worst hit by water resources scarcity and this has major ramifications for sustainable development in the region. This study examines the impact of water resources scarcity on sustainable development in the Sahel and proposes pathways for better water resources management in the region. Data were collected through an in-depth review of literature. Findings indicate that, although the Sahel region sits on one of the largest aquifers in the world, it is hard-hit by water resources scarcity. Water resources scarcity has adversely impacted sustainable development in the region through a worsening in the health situation of the population (caused by increasing incidence of water-borne diseases and unhealthy sanitary conditions); a decline in agricultural production; reduction in water available for use in the domestic sector, industry and energy sectors, and cities; and an ecological crisis. All these adversities induced by water resources scarcity in the Sahel significantly impede sustainable development. Proposed pathways for the sustainable management of water resources to ensure sustainable development in Africa’s Sahel are: more community-based integrated watershed management initiatives; better community and stakeholder engagement in water resources management; good policy frameworks in the water resources sector; good governance mechanisms in the water resources sector; and the vulgarization of climate-smart and nature-based solutions for landscape restoration.

ABSTRACT. The Canary Islands are an archipelago belonging to Spain, which is, in turn, divided into two provinces. The eastern province is the closest to the Sahara Desert, with the island of Fuerteventura being only 100 km from the African coast. Additionally, Fuerteventura is the oldest island in the Canary archipelago and one of the islands where the desertification process is most acute. That is why, in this article, we have reviewed the current state of water resources on the island of Fuerteventura and how nature-based solutions can be a great environmental solution. Specifically, the artificial recharge of its aquifer through lagoon systems can be fundamental to recover its biodiversity, improve the quantity and quality of its water resources, and gradually slow down the desertification processes affecting the island. Finally, we present the main conclusions, especially after previous experience in the feasibility studies of artificial recharge of aquifers on another of the Canary Islands, Gran Canaria.

ABSTRACT. Mathematical modelling has emerged as an indispensable tool for sustainable wastewater management, especially for the simulation of complex biochemical processes involved in the activated sludge process (ASP), which requires a substantial amount of data related to wastewater and sludge characteristics as well as process kinetics and stoichiometry. In this study, the results of the calibration of the activated sludge model n°1 (ASM1) developed by the International Water Association (IWA) implemented in GPS-X (General Purpose Simulator) software for the full-scale wastewater treatment plant of Maghnia City are presented. The model calibration process involved collecting and analysing 56 samples from the plant over the period of July 2021 - January 2023, thirteen physicochemical parameters were analysed. The parameters related to microbial respiration in GPS-X based on ASM1 were calibrated according to the influent characteristics. These modifications resulted in a reasonable alignment with the investigated variables, enabling the accurate prediction of the wastewater treatment plants (WWTP's) steady-state behaviour in terms of chemical oxygen demand (COD), total suspended solids (TSS), and ammonium (NH4-N) removal measurements. The model was validated using 14-day measurements spanning a 4-month duration, and the results indicated good agreement between the measured and simulated effluent variable of chemical oxygen demand (COD) with 23% root mean square error (RMSE). It is found that the application of the ASM1 Model can be a useful tool to understand and manipulate the complex dynamics of the activated sludge process in wastewater treatment plants.

ABSTRACT. During the outbreak of COVID-19, the sale of sanitizers has witnessed exponential growth. Sodium hypochlorite (NaOCl) has been the most effective and affordable disinfectant. However, it generates disinfection byproducts (DBPs), which are mostly carcinogenic. It also oxidizes heavy metals (e.g., Pb) and converts Br- to the mutagenic BrO3-. Thus, it is crucial to remove ClO- and its DBPs from sanitized water before reusing it in beneficial purposes such as agriculture and irrigation. To study its removal, a robust and reliable method for monitoring ClO- in sanitized water is necessary. The existing methods are ambiguous and impractical. In this work, a spectrophotometric method has been adapted and optimized for determining ClO- in sanitized water. The method is based on the chemical reaction of ClO- with I- to produce I3- that reacts with starch to produce a blue-colored complex (λmax = 605 nm). Although both reactions are well-known, no reports have been published on their use for determining ClO-. The progress of the two reactions has shown to be independent of pH in the range of 2-10. Of the three types of starch examined, a soluble starch (Sigma-Aldrich, potato biological source, S9765) showed the highest calibration sensitivity. A 0.075% starch was found to be adequate to react and solubilize I3-. The best linearity of the calibration curve was obtained using 2.5⨯10-3 mol L-1 I-, avoiding salting out of starch-I3- at high I3- concentration. Under these optimal conditions, both reactions are instantaneous and provide for a calibration sensitivity of 31382 L mol-1 cm-1 and a linear range of 0 - 2.5 ppm ClO- with detection and quantification limits of 0.018 ppm, and 0.061 ppm, respectively. The adapted method has been successfully applied for the determination of ClO- in swimming pool water samples. Moreover, the proposed method has been utilized to monitor the ClO- and the I3- concentrations during the study of the removal of ClO- based on its reaction with I- and subsequent adsorption of the produced I3- on cheap adsorbents. A commercial sponge and five batches of charcoal powder (activated and inactivated) have been employed to check their efficiency in adsorption of I3-. The results showed that I3- is completely adsorbed on the three examined batches of activated charcoal and partially adsorbed on the sponge while no adsorption was observed using inactivated charcoal. The adsorption capacity of the activated charcoal towards I3- was measured as 7.62 g/g. In a comparative study utilizing the proposed spectrophotometric method to monitor the concentration change of both I3- and ClO- against the mixing time with activated charcoal has revealed that the rate of adsorption I3- is faster than the adsorption of ClO-.

ABSTRACT. This study aims to identify and map flood-prone green spaces in Ain Temouchent, located in the northwest of Algeria, using a geographic information system (GIS). The objective is to establish a solid foundation for the development of a flood management plan specifically tailored to the environmental characteristics of the area. To achieve this, a mapping of the flood-prone areas was created by intersecting three key thematic maps at the watershed level. The main parameters considered for flood risk assessment include terrain topography, elevation, and slope exposure. The integration of these data allowed for the generation of a detailed map highlighting areas with significant vulnerabilities that require priority attention in terms of planning and development. The resulting classification of the flood-prone areas consists of four distinct categories ranging from low vulnerability to highly vulnerable. An important observation is that the sensitive zones cover almost the entirety of the study area, reflecting the current state of degradation of the sub-watersheds. This finding emphasizes the urgency of implementing specific management measures to mitigate flood risks in the region. The study outcomes provide precise and reliable information to local authorities and urban planners regarding areas exposed to flood risks. This in-depth understanding will enable them to design and implement targeted development strategies aimed at reducing the impacts of flooding, while considering the specific geographical and environmental characteristics of the region.

ABSTRACT. In the textile and pharmaceutical industries, production processes generate large volumes of effluents with high potential to pollute receiving environments, in addition to their high water consumption. The effluent contains residues of dyes and drugs as well as various carcinogenic and mutagenic chemicals and a lot of salt. For this reason, many treatment processes of the industrial effluent have been developed in recent years. In this work, we focus on hybrid and innovative processes that have been optimized at laboratory scale and are being tested at pilot scale thanks to the financial support of the TRUST-PRIMA project. The objective aims to preserve the water resource that is important for Mediterranean countries, especially those on the southern shore which are more exposed to water stress. The performance and sustainability of the treatment processes are analyzed according to two levels of quality of the treated water. The first is recycling in industrial processes and the second is achieving agricultural water quality standards for irrigation. The processes optimized on a pilot scale are subjected to the analysis of environmental and economic sustainability by two relevant and multi-criteria tools which are the life cycle analysis (LCA) and the cost cycle analysis (LCC). The results of a combined LCA-LCC analysis allow the determination of specific and complementary sustainability indicators. Specific indicators include scores on environmental impacts and damages such as human health, ecosystem quality, climate change and resource depletion. Complementary indicators include economic costs as well as the quality of sludge and treated water that is intended for reuse in industry or irrigation.

ABSTRACT. All organisms, including humans, need clean water to survive. This goal requires river and estuary pollutants monitoring. Persistent organic pollutants (POPs) like hexabromocyclododecane (HBCDD) and 2,2',4,4',5,5’-hexabromobiphenyl (BB-153) and toxic elements (TEs) like arsenic (As), chromium (Cr), and nickel (Ni) harm human health and the environment, according to the UNEP. HBCDD harms aquatic plants and animals, whereas BB-153, As, Cr, and Ni may cause human cancer. Buffalo River Estuary (BRE) is in East London, Eastern Cape Province, South Africa. Some of the anthropogenic activities taking place in and around BRE include fishing, bowling, swimming, and ship berthing. Residential and industrial waste from First and Second Creek effluents pollute the estuary. Organochlorine pesticides (OCPs), total petroleum hydrocarbons (TPH), phenolic derivatives, and polyaromatic hydrocarbons (PAHs) have all been found in BRE. HBCDD and BB-153 have never been reported in BRE. Thus, this study examined BRE's surface 108 samples of water and sediment HBCDD, BB-153, Cr, As, and Ni levels and risks in 2020. ALBFRs were extracted using solid-phase and ultrasonic-assisted methods. GC-MS and GC-ECD were used to detect and quantify the analytes, while ICP-MS measured toxic elements (TEs) levels. BRE's surface water included BB-153, HBCDD, As, Cr, and Ni at quantities ranging from not detected (n.d.) to 0.03 μg/L, from n.d. to 0.064 μg/L, from n.d. to 3.89 μg/L, from n.d. to 2.91 μg/L, and from 0.028 to 3.946 μg/L, respectively. BRE sediment included n.d. to 508 mg/kg (dw) of BB-153, 0.009 to 426 mg/kg (dw) of HBCDD, 0.021 to 20.5 mg/kg (dw) of As, 0.220 to 64.5 mg/kg (dw) of chromium, and 0.078 to 28.3 mg/kg (dw) of nickel. The Hazard Quotient (HQ) risk assessment shows a low risk of non-cancerous diseases for adults and children. However, for cancer risk (CR) in adults and children, the number exceeds 10-4, indicating a high risk for estuary swimmers due to trace element exposure, notably chromium (Cr).

ABSTRACT. Clean drinking water is necessary for human survival and different life forms. Yet, water scarcity is still a central theme globally, especially in arid and semiarid areas and is responsible for various effects, including drought and famine, deaths, the spread of water-borne diseases, enforced migrations, and open conflicts. Since water scarcity is closely allied to food and health security, it is important to make better water management a priority. If the water scarcity issue is not addressed urgently, most of the arid and semiarid regions are likely to experience significant issues in managing inland freshwater in a few years. The primary objective of this paper, therefore, is to explore a simple but cost-effective approach for extracting water from the atmosphere using solar energy. The suggested system works as an absorption-based Atmospheric Water Absorber (AWA) that takes advantage of the promising climatic conditions in areas with elevated temperatures and humidity. The study involves both theoretical analysis and experimental testing, focusing on the use of lithium bromide (Li-Br) as the absorbent material for efficient water extraction. The paper begins with an overview of the importance of clean drinking water and highlights the increasing global demand and vulnerability to water scarcity. The paper reviews various water extraction techniques, emphasizing the potential of the atmospheric water absorber process for meeting water requirements in water-stressed regions. The design of the solar-based AWA unit involves key components, including an evaporation basin, glass cover, circulating pump, absorbent solution (Li-Br), tanks, valves, and collector tubes. The unit operates in two phases: night-time absorption, during which the absorbent collects water vapor from the ambient air, and day-time desorption, when solar energy heats the weak absorbent to release the captured water vapor, which condenses on the cool glass cover. Performance analysis and experimental results demonstrate the system's efficiency and water production capabilities. The study considers factors such as ambient temperature, humidity, solar intensity, and absorbent concentration, and their influence on the rate of water production. The research also explores the impact of varying the flow rate of the absorbent on the unit's performance. The experimental data show promising results, with the system producing approximately 0.24 liters of water per hour under specific climatic conditions. In conclusion, the absorption-based atmospheric water absorber method shows potential as a viable and energy-efficient approach for extracting water from the atmosphere. Since solar energy is a significant source of heat in this system, it makes it suitable for use in remote areas and those located off the grid. Though the system’s performance results show a high level of effectiveness, additional optimization and testing is necessary to review performance under different environmental conditions. Additionally, economic studies are crucial to determining the feasibility of AWA systems and their potential for widespread adoption as a sustainable solution to address water scarcity challenges. With continued research and investments, AWA systems could play a vital role in securing access to clean drinking water in water-stressed regions worldwide.

ABSTRACT. The main objective of this work is to evaluate the physicochemical characteristics of the soil in the irrigated perimeter of Hennaya (Tlemcen province) following irrigation with purified wastewater from the Ain El Houtz wastewater treatment plant. The reuse of purified wastewater represents a very serious solution in a water supply situation that is highly dependent on the vagaries of weather. However, the adoption of a periodic monitoring protocol at several levels (soil texture, water table, crops applied...) is essential to combat the negative effects (health and environment) that have been proven by previous experiments and studies. In this study, soil samples were taken at different depths for different periods to examine the condition of the soil after 10 years of irrigation. The results showed that the region's soils are predominantly clay and silt, with limestone present in excess of 15% (confirmed by an alkaline pH ranging from 7.7 to 8.9). The observed values of electrical conductivity do not present any risk of salinization and/or degradation and are not a constraint to plant development (< 0.6 dS/m). Exchangeable base values (Ca++, Mg++, Na+, and K+) confirm the calcareous nature of the soils. This shows a predominance of the element calcium on the adsorbent complex. On the other hand, the determination of trace metal elements (TMEs) in the soil shows an indicative presence of certain elements such as Cobalt (around 30 mg/Kg), and Cadmium (around 2 mg/Kg) due to raw wastewater irrigation practices in certain plots. The results obtained from this study also show that irrigation with treated wastewater can lead to long-term saturation of the soil with mineral salts, which in turn can degrade the physical and chemical quality of the soil. The quality of treated water must be strictly controlled to ensure the sustainability of this type of project without compromising the surrounding environment.

ABSTRACT. Dams are supply infrastructure that holds water for municipal and other purposes, thus important and obligatory to monitor the water quality of municipal dams. This research aims to evaluate the water quality of the raw Keddara dam on the Boudouaou River in Boumerdes Province, Algeria, using conventional water quality index (WQIs) methods. For this study, secondary data was collected for the period of 25/12/2018 – 24/06/2021 comprising 11 parameters - Temperature, Ph, Conductivity, Turbidity, Total Dissolved Solids (TSS), Full Alkalimetric Title (TAC), Hydrometric title (TH), Nitrogen dioxide (NO2-), Nitrate (NO3-), Ammonia (NH4+), Phosphate ion (PO43-). To prevent any skewing of the information derived from the data, missing values and outliers were removed from the data using the Box Plot approach outlined by Tukey. The data was subjected to the Shapiro-Wilk test, Kolmogorov-Smirnov test, and Quantile regression approach. To evaluate the water quality of the dam Weighted Arithmetic Method (WAM) WQI and the Canadian Council of Ministers of the Environment (CCME) WQI was used. This study employed the WHO standards and all of the indicators were within the allowable limit for WHO standards except for conductivity, turbidity, TH and TAC. Results of the water quality of the Keddara dam show that the WAM WQI ranges from 9.52 (excellent) to 17.77 (excellent) and CCME WQI ranges from 81.92 (good) to 95.08 (excellent). This study gives evidence that the Keddara dam is suitable for municipal purposes. Although the water quality index results generally show the water is suitable for consumption, the descriptive characteristics of the raw Keddara water show that turbidity, TAC, total hardness and electrical conductivity exceed the WHO permissible limit. Hard water indicates the presence of dissolved ions which directly increases electrical conductivity. Thus, it is recommended that more study is done to investigate the Keddara treated water, to confirm that these parameters are within the WHO permissible limit.

ABSTRACT. Groundwater is a crucial source of freshwater for drinking, agricultural, and industrial purposes. The presence of contaminants such as pesticides and their transformation products (TPs) and contaminants of emerging concern (CECs) in groundwater has gained attention due to the growing need for groundwater use. The sources of contamination include point emissions and diffuse sources such as agricultural runoff, industrial discharges, septic systems, and crop irrigation with reclaimed wastewater. Herbicides and their TPs are the most frequently detected compounds in aquifers. While global research concerning the presence of CECs and pesticides has increased, studies in the Middle East North Africa (MENA) region, including Tunisia, remain scarce. In Tunisia, there is limited knowledge regarding the presence of CECs and pesticides in groundwater, and the few studies published have mainly focused on wastewater treatment plants. The challenging analysis of CECs and pesticides at trace levels mostly relies on international scientific collaborations, resulting in few data, and scientific research on CECs is still lagging in Tunisia. Consequently, evidence on many anthropogenic organic substances in groundwater is missing to adequately inform national policy on this topic. Although Tunisian regulations do not consider this aspect, collaborative efforts within the framework of various Research and Innovation projects have been undertaken to address the gaps in knowledge and enhance water quality management in Tunisia. Assessing the potential risks associated with these chemicals through environmental risk assessments can guide regulatory decisions and inform water management strategies. To enhance groundwater quality in Tunisia, it is imperative to conduct further research aimed at developing innovative water treatment solutions specifically tailored to address the identified contaminants. This involves exploring advanced filtration systems and integrating machine learning approaches for precise quality assessment. Additionally, a concerted effort is required to seamlessly integrate these research findings into regulatory decisions and national water management strategies. Special attention should be given to promoting the secure utilization of reclaimed water for irrigation, coupled with active advocacy for stringent wastewater treatment standards. Furthermore, fostering collaborative initiatives among local authorities, research institutions, and the public is essential to raise awareness about the critical importance of groundwater quality. This comprehensive approach seeks to cultivate a deeper understanding of groundwater issues and advocate for sustainable water management practices throughout Tunisia.

ABSTRACT. As known agriculture is the maximum fresh water user activity in world general. While this rate is around 70% worldwide, it is over 80% in semi-arid Konya plain of Turkey. Considering average annual rainfall of around 300 mm in the Konya plain, one of the agro- production centers within Turkey, it is not possible to produce economically vegetative production especially from summer plants without irrigation. Such plain is one of the regions where the negative effects of climate change are most affected and where agricultural drought has frequently been experienced recently. Negative effects of climate change in the region include decreases in surface water levels and complete drying in some lakes. In this study, the existing water and plant production assets of the Konya plain were analyzed and then feasible suggestions were made for the economical use of current water resources in agriculture. In result, it has been excessive water withdrawal from groundwater resources for irrigation purposes and even alarming depletions in water levels have been observed in some parts of the Konya plain. In brief, groundwater resources have not been used sustainably in the light of current agricultural practices. It has been concluded that two important reasons for the excessive use of water resources in region are the unplanned growth of irrigated areas and the increase in the cultivation areas of plants with high water consumption such as both forage and grain maize. The first step to take for productive use of water resources is to regulate planting patterns in the region according to the current water resources. In addition, it may be recommended to expand the application areas of irrigation technologies leading to high irrigation water savings such as sprinkler and drip irrigation, to implement deficit irrigation programs for some crops such as sugar beet, maize, sunflower, common bean, potato in field conditions.

ABSTRACT. The availability of water contributes significantly to economic growth, food security, and socio-economic development. All human beings use water to meet their economic and daily activities, which can be a challenge in many countries, especially in the Middle East and North Africa such as Morocco. Recently, water availability has been decreasing due to the effect of climate change, which is even more problematic in areas where demand is increasing as a result of population growth. Where available, groundwater can offer a choice to meet the population's daily water needs. However, the use of groundwater through unsustainable extraction practices has led to a sharp deterioration of the water situation. In response to this water crisis, the Moroccan government has implemented some important preventive measures, including water strategies, policies, and programs to achieve a balance be-tween the supply and demand of water. While existing literature predominantly emphasizes the description of groundwater management policies and compares them across different countries, here we use a qualitative tool of economic analysis in Al-Haouz Mejjate Aquifer, Morocco. This study aims to enhance the understanding of water users' decision-making and behavior in the context of groundwater management.

To accomplish this, semi-structured interviews were conducted with more than twenty water users from two sub-basins within the Al-Haouz Mejjate Aquifer in Morocco, and the data was analyzed thematically. This study sheds light on the most common challenges faced by water users in the Al-Haouz Mejjate Aquifer, notably water scarcity and the impact of climate change. Furthermore, water users’ perceptions and behaviors regarding groundwater use are analyzed in the context of participatory groundwater management policies.

Consequently, the results obtained here highlight the importance of addressing these common water challenges and call for policymakers and stakeholders to improve and develop more effective policies to achieve sustainable water management in arid and semi-arid regions.

ABSTRACT. The Ogallala Aquifer located in the semi-arid region of Kansas, USA is significantly over-appropriated. The rate of decline in some areas of the aquifer is steep such that future economic viability in the region is at stake. The groundwater management districts (GMDs) were given authority by the 2012 Legislature to initiate a voluntary public hearing process to consider a specific conservation plan to meet local goals. Sheridan #6 Local Enhanced Management Area (LEMA) was formed which is proactive, locally designed, and initiated water management strategies for a specific geographic area. Sheridan 6 LEMA was enforced from 2013-2017. During this period, farmers within this area voluntarily committed themselves to reducing water use by approximately 20% of their historic water use. Farmers within the boundaries of the LEMA were assigned a 5-year allocation of 1.40m per hectare. During the period, farmers changed some of their farming operations, crops planted, management techniques, and irrigation practices. Many of the farmers used new irrigation technologies to better manage their farms. A study was conducted to compare the economic performance of farmers inside the LEMA versus farmers outside the LEMA. Irrigated corn producers within the LEMA boundary reported using 23.1% less groundwater use and yielding 1.2% less corn as compared to irrigated corn producers outside the LEMA boundary. Surprisingly, irrigated corn producers within the LEMA boundary reported 4.3% more cash flow than their higher-yielding counterparts outside the LEMA. The groundwater level decline reduced from 0.61m per year to 0.13m per year. This management program was deemed successful and the farmers renewed their voluntary commitment to another five years or until 2027.

ABSTRACT. Private tanks are one of the most important components in the water distribution systems as there are a significant interaction between reservoirs and the water distribution networks because they affect the qualitative and quantitative aspects of the water. However, local private tanks are usually ignored during the design stage in favor of simplified network analysis. It is a common practice based on water distribution codes of many countries that hardly specify any range of values for the physical attributes of the private tanks. In fact, neglecting parameters such as inlet orifice size could result in tank failure if not designed properly. The purpose of this study is to determine the optimum values of different tank parameters by conducting time and volume-based reliability analysis so that the pressure in the system does not lead to high heat loss. Two sample networks were taken from previous literature. The simulation of local tanks was conducted using the software ‘WDnetXL’ while the reliability analysis was conducted separately using MS EXCEL. The results showed that the orifice size and volume of each local tank has a great influence on the reliability of the tanks. The general trend shows that the increasing the orifice sizes and volume capacity increases the value for both reliability indicators. In fact, it was further observed that changing the orifice diameter even slightly could easily help in achieving the required reliability than changing the volume capacity. This was indicated when the required reliability value of 1 was achieved by just increasing the orifice diameter from 3cm to 5cm. However, in the case of the capacity of the private tank, higher capacity often only results in providing additional volume. In a longer simulation run, the network would lose its reliability as water is consumed by the user. The results also discuss the impact of orifice sizes and volume capacity on the pump’s carbon footprint. An increase of 5 cm of the orifice size of a single tank could result in an increase in the 10% of the overall carbon footprints. Moreover, the result indicated that the lowest orifice and volume size(s) to achieve the required reliability of unity is the optimum dimensions of the tank. Any increase on the optimum value of orifice size and retention time would result in an increase in the pump’s carbon footprint and drop in pressure. In fact, a drop of 10m was observed when the orifice size(s) were increased by 5cm of their optimum value. Hence, the incorporation of private tanks in the network model can be very vital as it brings changes to the resulting parameters of the network.

ABSTRACT. In Morocco, climate change through water scarcity, and increasing salinity levels is significantly impacting the agricultural landscape. These intertwined challenges have far-reaching implications, not only for the livelihoods of farmers but also for broader socioeconomic aspects. As rising temperatures and decreasing precipitation patterns disrupt traditional farming practices, farmers find themselves navigating a complex environmental stressor that threatens their social well-being and the Moroccan economy since it is highly dependent on agricultural activities. This study employs a methodology centered on in-depth interviews with 48 farmers across three distinct regions “Rhamna”, “Qelaa Sraghna”, and “Tadla” aiming to compare their perceptions and shed light on their adaptive strategies in the face of these pressing environmental issues. Thematic analysis was employed in this study to identify, analyze, and report themes within the context of salinity and water scarcity. These coded themes are then organized into overarching themes that capture significant aspects of the data. Furthermore, our comparative analysis aims to highlight similarities and differences in their perceptions and adaptations to these urgent environmental hurdles, shedding light on the multifaceted dimensions of the problem. Descriptive statistics and thematic analysis revealed that farmers' decision-making in the context of water scarcity and salinity is a complex interplay of individual experiences, local context, and broader environmental factors. In this context of salinity and water scarcity, farmers adapt their practices in response to these agricultural constraints. However, their adaptations can be inappropriate due to their lack of awareness and differing perceptions of the causes and impacts. Large-scale farmers predominantly utilize organic amendments as their primary adaptation strategy, followed equally by using more fertilizers, adopting tolerant crops, and other methods, such as digging more boreholes and leaching. Conversely, small-scale farmers favor crop tolerance, organic amendments, leaching, additional well digging, and increased fertilizer usage as their predominant adaptation strategies. Notably, the perception of fertilizer usage varies among farmers, with some viewing it to reduce salinity effects and others perceiving it as a contributor to salinity issues. This study also delves into farmers' perceptions of the causes and impacts of salinity and their relationship with adaptation strategies. Additionally, multiple regression analysis was employed to explore the associations between specific adaptations and the socioeconomic characteristics of farmers. The findings from these regression analyses revealed significant correlations between adaptation strategies and these socioeconomic variables. Eventually, this study will not only enhance our understanding of the challenges faced by farmers but also offers valuable insights to inform the development of adapted policies aimed at fostering resilience and sustainability in Moroccan agriculture.

ABSTRACT. Algeria is among the semi-arid or even arid countries that suffer from drought, where precipitation does not exceed 400 mm/year and water resources are scarce, irregular and located in the coastal strip. In the Algerian Sahara, non-renewable groundwater resources estimated at 5 billion m3 thus constitute the indispensable support for irrigation. This is especially the case since agricultural development programs, aimed at integrating the Sahara into the national economy, have based on an agri-food model implemented outside existing oases through the conquest of new agricultural land and the use of pumped groundwater. In the Berriane region in the north of Ghardaïa region (center of Algerian Sahara), an agricultural perimeter called Oued El Bir (300 ha in total) was officially created in 2013 downstream a wastewater treatment plant. Farmers had informally settled in the area, already a wastewater discharge site, since 2009 and had practiced unofficial irrigation with raw wastewater, a “frontier settlement” that proves the high value placed on this resource. As part of Massire project financed by IFAD (2018-2024), the objective of our study was to analyze the water reuse practices in this Berriane arid region, i.e. to study the importance of the institutional management of the treated wastewater reuse on the one hand. And on the other hand to show that the malfunctioning of the wastewater treatment plants can lead to many constraints such as the infiltration of raw sewage into the groundwater, illicit untreated wastewater irrigation and a slowdown in the development of the agricultural perimeter. Our research methodology is founded firstly on interviews with all stakeholders (about 20 surveys with farmers and local institutions) and secondly on isotopic, chemical and biological water analyses that will be carried out soon to validate the hypothesis of infiltration of wastewater into the aquifer. In addition, to overcome of the institutional resistance, we also built with local stakeholders a water reuse demonstrator in a regional eco-neighborhood. The decentralized treatment process is based on a sceptic tank and a fixed bacterial filter (Advanced Enviro Septic) with 10 m3/day capacity. The treated wastewaters are used to irrigate a 1 ha surface of new oasis area. As part of our study, we are investigating the sanitary and agronomic safety of this new treatment process for water reuse in the arid context.

ABSTRACT. With the metamorphosis of the residential landscape worldwide and sluggish sanitation strategies in urban environments, rudimentary on-site sanitation systems remain commonly used, especially around the Mediterranean region, despite the risks of groundwater contamination. The effective management of such water resources relies on assessment of the sensitivity of anthropized aquifers to man-made impact, including groundwater behavioral alteration, in terms of both quality and quantity. Associated with tracking of changes in land use, this study proposes an approach involving emerging organic contaminants (EOCs) as indicators of the alteration of groundwater balance due the exposure of shallow aquifers to the risks of infiltration of untreated wastewater from sewage defects. This methodology was applied to the shallow aquifers beneath two major cities in Tunisia and Corsica respectively in arid and semi-arid hydrocontext. Combined with an updated follow-up of groundwater piezometric fluctuations in relation with inputs from surface contamination sources, the spatialization of contamination levels by EOCs provided a clear delineation of the most impacted aquifer zones. This approach revealed a significant link between the continuous rise in piezometric levels by contributions from untreated inputs and the accumulation of high levels of contamination in groundwater for the Tunisia case study. It also highlighted the main threat that contaminated groundwater by EOCs represent for the hydraulically connected coastal wetlands for the Corsica case study. The understanding of EOC underground pathways allowed the determination of the fates and processes responsible for the diffusion of contamination throughout the studied aquifers. The ability of groundwater to reflect population life style and the use patterns of such organic molecules was also assessed. Besides revealing the legacy of persistent contamination, this approach involving EOCs as tracers with different levels of persistence provided a spatial observation of the aquifer exposure to continuous contamination processes. This approach made it possible to develop a conceptual presentation of aquifer vulnerability to urban pressures and to predict the effects of subsequent expansion of unplanned urbanisation on groundwater quality.

ABSTRACT. According to the IPCC reports, the effects of climate change are well present form several decades ago and will become more pronounced in the 21st century. The river basin system is defined as a complex of interacting aquatic and terrestrial ecosystems. The interface between these ecosystems result in different responses ranging from floods to low flow. The instability of alluvial valley represents an additional challenge for the riparian societies face to climate changes. The Garonne River sinks in the Garonne Valley, the largest occupied and cultivated alluvial plain in Franc. The inhabitants in this area are strongly depending to the River and its surrounding alluvial aquifer. However, adapting to climate changes becomes a major objective of the basin's water policy. The alluvial aquifer forms an important part of River's system, maintaining a strong hydraulic relationship with the River and sustains its low flow. Consequently, this aquifer is extremely sensitive to annual climatic fluctuations and recharge variation. The trends assessment of the River's discharge over the last fifty years has shown a decrease in both low flow and mean annual discharge. The dry periods are starting earlier and becoming more severe and longer. Groundwater measurements show a general decrease in water level, and most of wells near the River have dried up during the dry periods due to aquifer drainage into the River. This could have a negative impact on agriculture, wetlands, and river ecosystems. Thus, the implementation of adaptation measures has been initiated including artificial recharge of the alluvial aquifer to address the effect of climate change and sustain the low flow of the Garonne River. Several pilot sites in the Garonne Valley are under investigation, and two of them have already tested for the artificial recharge. The results of direct measurement and groundwater modeling show the efficiency of this methodology in maintaining the groundwater level and sustaining the River's low flow. The first site is located near the city of Agen, where the runoff water is collected in retention basin and is used to recharge the alluvial aquifer. Groundwater level in the wells located near the retention basin has increased by more than 1 m following a rainfall event. The results of the groundwater modeling show a similar magnitude aquifer response the to the induced infiltration. This result shows that the infiltrated water would take about 4 months to reach the Garonne River, which is an appropriate time to maintain its low flow. The second site is located near the city of Marmande where the surface water from the lateral canal has been used as a source for recharging the alluvial aquifer in May 2023 by using a ditch located in front of this canal. The groundwater level measurement shows an increase of 0.15 and 0.33 m into two wells located approximately 40 m upstream and downstream of the infiltration site respectively. This experiment will be carried out on a larger scale, and further groundwater measurements and modeling will be archived for this site and other selected sites.

ABSTRACT. In the context of a changing climate, arid regions face a variety of challenges, one of which is estimating extreme rainfall events. As climate change increases the frequency of extreme rainfall events, especially in arid areas, the need for accurate extreme rainfall events, such as Probable Maximum Precipitation (PMP), under climate change scenarios becomes a standard practice and a critical component of water management infrastructure.

Estimating rainfall events accurately in arid climates under changing environmental conditions is a critical challenge in the dam and crucial infrastructure design. While making the most of available information, it is essential to reduce uncertainty in estimating extreme rainfall events and their impacts.

In the context of climate change scenarios, PMP, which is a measure of the theoretical maximum potential rainfall for a given duration, watershed, or storm area, is expected to change over time alongside other hydroclimatic variables. PMP estimation is heavily dependent on available data and methodology, resulting in significant variability in results. This variation has a significant impact on water management systems, given that PMP is crucial to estimate the probable maximum flood. As a result, one key challenge is to accurately estimate this parameter under changing climate conditions, striking a balance between underestimation and overestimation based on available data.

This study presents a localized PMP estimation that takes into account climate change, employing two approaches: statistical approach, knows as Hershfield method, and a physical approach involving storm moisture maximization. Climate change assessment is based on the NASA Earth Exchange Global Daily Downscaled Projections dataset, which comprises globally downscaled climate scenarios derived from the Coupled Model Intercomparison Project's sixth version (CMIP6).

Combining gridded satellite meteorological data and information from meteorological stations, the GCMs were bias-corrected using Quantile Delta Mapping. PMP estimation was conducted using both methodologies across all available GCMs, two Social Shared Pathways (SSPs), and different future horizon periods. A rate of change or anomalies were estimated to describe the influence of climate change conditions on the PMP values, by dividing the difference between the projected PMP and the corresponding baseline PMP.

PMP values tend to rise with both methodologies, with higher long-term values compared to mid-term values. Across the same period and SSP, rate variations were observed on median values, dependent on the methodology applied. These varying PMP values necessitate different design considerations for each project stage, having a significant impact on risk assessments, design, and investment decisions throughout a project's lifecycle.

ABSTRACT. The Sahel region of Africa is one of the driest and most drought prone regions in the world. With a surface area of 3,053,200 km2, a population of over 150 million people and an annual rainfall varying between 100-200 mm and 700-1000 mm in the northern and southern parts of the Sahel respectively, the region is an epicentre of environmental crises. These environmental crises have induced water resources scarcity in the region, necessitating proper adaptive management to counter the precarious situation of water resources scarcity. This study lays emphasis on the risks, externalities and adaptive management situation in the Sahel region faced with the problem of water resources scarcity. The methodological approach used was in-depth review of existing literature. The findings of the study indicate that, the main risks to water resources availability in the Sahel are droughts, climate change, conflicts and extremism, population growth, floods, land degradation and political instability (frequent coup d’états). Water resources scarcity in the Sahel exposes the region to different externalities with the major ones being food insecurity, gender inequality, conflict and violence, and migration. Adaptive management to water resources scarcity in the Sahel continues to be problematic largely due to governance issues, global warming and climate change, limited application of the polluter-pays-principle, and limited integrated water management practices. All these short comings to adaptive management of water resources scarcity in the Sahel has contributed to worsening the already precious situation. This paper recommends that a more proactive and robust adaptive water resources management approach be adopted across Africa’s Sahel region in order to curb the water resources scarcity crisis in the region.

ABSTRACT. Sunflower (Helianthus annuus L.) is an important oilseed crop widely adopted and accepted for its high quality edible oil of 30-50%. Sunflower is cultivated mainly in tropical and subtropical regions with climatic conditions ranging from semi-arid to arid as a edible oilseed crop. Since it is a photo insensitive crop, cultivated primarily as a rainfed crop both in Kharif and with residual soil moisture during rabi in India. Hence, sunflower production is influenced by several weather factors, such as heat, drought and other abiotic stresses. In fact, large area under sunflower is cultivated under rainfed situation, where intermittent moisture stress is most prevalent. Developing varieties and hybrids with high yield even under stress conditions is prime strategy compared to other management practices to avoid yield loss. The present experiment was conducted to screen sunflower recombinant inbred lines and CMS lines for moisture stress tolerance and its effect on physiological and yield parameters particularly at vegetative (45 DAS) and flowering stage (60 DAS) by withholding the irrigation at those crop growth stages compared to control where crop was provided with normal irrigation up to crop maturity. This investigation revealed that physiological traits such as specific leaf area, relative water content, SPAD and photosynthetic rate exhibited more reduction in susceptible genotypes as compared to tolerant/resistant sunflower genotypes. Whereas proline content increased in moisture stress compared to control under varied moisture stress conditions. The genotypes namely CMS-105B, CMS-38B, RSLP-24, RSFH-700 and PM-81 have showed least per cent reduction in photosynthetic rate. Stress treatment induced marked less reduction in leaf number in RSLP-41 (8.95 per cent), RSLP-24 (11.49 per cent), RSLP-14 (12.93 per cent). For specific leaf area, RSLP-24 (4.49 per cent), RSLP-41 (11.70 per cent), RSLP-14 (11.39 per cent) and RSLP-33 (16.71 per cent) recorded less percent reduction compared to other genotypes which recorded 15-20% reduction in specific leaf area. The soil moisture stress recorded repressing effect on yield related attributes viz., seed yield (33.23 %), total number of seeds per head (24.89 %), head diameter (24.41 %) and oil content (0.16 %) compared to control. The study identified four recombinant inbred lines viz., RSLP- 14, RSLP-44, RSLP-33, RSLP-24 and one CMS line CMS-105B as moisture stress tolerant lines. The identified multi-branched recombinant lines and CMS line could be used to generate new sunflower hybrid combinations particularly for moisture stress situations in rainfed agriculture.

ABSTRACT. The main purpose of this work was to assess the ability of mixed physical barriers (MPB) to protect coastal groundwater from seawater intrusion in realistic heterogeneous coastal aquifer settings. Laboratory experiments were completed in a laboratory-scale aquifer where the performance of MPB was examined in a typical stratified aquifer where a low permeability layer was set in the middle part of the aquifer as an interlayer (case HLH). The performance of the MPB was compared to that of a traditional cut-off wall. Numerical modelling was performed for validation purposes, to further evaluate the effectiveness of MPB in five additional heterogeneous configurations, and to explore the sensitivity of the MPB performance to the wall design and geological parameters. The additional heterogeneous included various layered cases where a low permeability layer was set at the top of the aquifer (case LH), at the lower part of the aquifer (case HL), at the top and bottom part of the aquifer (case LHL), and two cases with monotonically increasing/ decreasing permeability from top to bottom. The results show that the MPB effectively reduced the saltwater wedge length by up to 71%. The MPB outperformed the single cut-off wall by up to 55 %. Numerical analysis of other layering patterns showed that the MPB remained effective in repulsing seawater intrusion. Aquifer stratification, nonetheless, altered the overall performance of the MPB to various degrees, depending on the aquifer layering pattern. The findings of this study provide insight into the effectiveness of the MPB system in realistic heterogeneous aquifer settings and further demonstrate its reliability as a practical measure for seawater intrusion control.

ABSTRACT. In many parts of the world, water managers are challenged as never before to do more with less. Snowpack appears to be decreasing and groundwater over drafting continues unabated in many regions. This increasing pressure on water has been highlighted in UN water report 2022. However, one of the great unknowns is the state-of-art climate models predicting future change in the spatial distribution of changing precipitation patterns. This lack of knowledge severely limits implementation of mitigation and adaptation options to divert the most severe consequences of climate change. Decision tools are needed to help water planners and decision-makers to better understand how water resources are affected by population growth, drought, climate change impacts, and water management policies, as well as to inform investment and policy changes around these factors. While number of water management scenarios have been used to increase the freshwater supply through desalination, improving water efficiency, reuse of treated wastewater and conservation measures, the potential for underground storage to sustain future supply is highly considerable. Storing water will be vital to adapt to climate change (World Bank report, 2022). The world faces a water storage gap as demand for fresh water grows and glaciers, snowpack, and wetlands decline. A new approach that integrates built and natural water storage is needed to holistically manage water throughout entire water systems. This paper will provide an overview of some of the research and education needs and priorities concerning sustainable underground storage approach. It will also assess geological, geochemical, biological, engineering, and institutional factors that may affect the performance of such projects, based in part on a review and evaluation of existing projects. Specifically, the study will assess and make recommendations with respect to research and education needs.

ABSTRACT. Water scarcity is one of the main challenges that Gulf Cooperation Council (GCC) countries have been facing for multiple decades. The challenge grows bigger as the region is experiencing rapid social and economic transformation leading to an increase in the water demands. Out of the various solutions that were implemented to face the challenge, the demand and supply side management was heavily investigated. The balance between water supply and demand requires efficient water management system techniques, which is highly dependent on the use of accurate forecasting methodologies and tools. Accurate demand forecast is a necessary input to many water processes such as determining the required water reserve precisely as well as developing optimum operational plans for pumping stations and water production plants. There is no global single optimum method used to forecast the water demand. It is more of a case-by-case approach depending on the network complexity, operational limitations, available data, forecast horizon, intuitiveness of the tool, accepted percentage of deviation between actual and forecasted demand. The purpose of this paper is to achieve the global sustainability goal by addressing the gap that is currently present between water supply and demand. This is done by presenting an innovative accurate methodology to forecast the water demand using machine learning (ML) for short-term. The results for a water utility in United Arab Emirates (UAE) showed that the mean absolute percentage error (MAPE) between the actual and forecasted demand was reduced from 5.42% for the conventional forecasting method to 3.25% for the proposed ML forecasting method. Similarly, the root mean square error (RMSE) was reduced from 11.14 million imperial gallons per day (MIGD) for the conventional forecasting method to 7.6 (MIGD) for the proposed ML forecasting method. Additionally, the total difference per year between the actual and forecasted demand was reduced from 2683 million imperial gallons (MIG) for the conventional forecasting method to 898 (MIG) for the proposed ML forecasting method. This shows that by having an accurate demand forecast, the gap between the actual and forecasted demand can be reduced which will improve the overall efficiency and performance of the water management system.

ABSTRACT. Fast water transfer to rivers during flood situations causes a water deficit during dry periods. For long-term retention of water in aquifers and its subsequent use in drier or heavier demand periods, the Managed Aquifer Recharge (MAR) techniques were studied and implemented in 4 pilot areas of the DEEPWATER-CE project funded by the Interreg CENTRAL EUROPE programme. For retention of surface water in aquifer and for recharge of groundwater and its subsequent using for irrigation during dry periods, the Recharge Dam MAR type was investigated in Slovakia using the groundwater numerical modelling technique. The calibrated and verified groundwater flow model was developed using MODFLOW within the GMS environment and was used for the prediction for two scenarios (prognosis) improving the water level regime in the channel system resulting in the improvement of the groundwater regime as well. By appropriate manipulation of the gate slides during flood situation we can increase the amount of water recharged to the groundwater by 11,000 m3.d-1 without further technical measures. After construction of 3 additional weirs, the amount of water recharged to the groundwater can be even higher.

ABSTRACT. Bangladesh has been considered as the most vulnerable country in the world to climate change and associated impacts. To meet-up the food security of huge population, Bangladesh became the world’s fourth biggest rice-producing country, but unavailability of adequate water is a common phenomenon in the north-western part of the country mainly during dry period which is well-known as ‘Barind Area’ dominated by uplifted Pleistocene Terraces. The Barind Tract is the product of vertical movements of Pleistocene period and reaches maximum height of 20 m above recent flood plains. The Barind zone, situated in the northern part of Bangladesh, is the most exposed area of the country to water scarcity. The monthly average temperature for the period 1980-2009 ranges from 100C (in January) to 330C (in May) and annual temperature increases at a rate of +0.0208°C/year in the area. The average monthly humidity varies from 62% (in March) to 87% (in July) where the annual magnitude of change is 0.094% per year. Average annual temperature is high in the western and north-eastern part while the eastern part is more humid than the western part. To support the irrigation demand, extraction of groundwater has been increased and the hydrogeological complexity, meteorological variability and climatic factors influence to increase the stress on this resource significantly. To combat the situation and explore the potential of Managed Aquifer Recharge (MAR), a pilot project was implemented by NGO Forum for Public Health in the Barind area that installed recharge wells using rainwater as a source of recharge, funded by Swiss Agency for Development and Cooperation. The study considered assessment of aquifer condition, groundwater quality, water level trend and recharge potentiality using primary and secondary data. In the study area, permanent lowering of ground water table was observed due to excessive withdrawal of groundwater in comparison to inadequate groundwater recharge during dry irrigation period. After application of MAR technique, ground water table started to rise in monsoon above the minimum depth to water table of previous years with the impact of artificial recharge. Therefore, the MAR, as an artificial groundwater recharge process, can be used as the potential groundwater recharge technology through rainwater in the drought prone Barind area to improve groundwater conditions in drought prone areas of Bangladesh. This study provides a description of an innovative MAR system which improves current ground water practice in water scare regime and toward building a resilient community. The generated lessons against tackling the operational challenges of water scarcity will provide good learnings for replicating similar practice in another areas.

ABSTRACT. The United Arab Emirates (UAE) faces significant water scarcity due to its arid conditions and rising water demands driven by population growth and economic expansion. With more than three-quarters of the country covered by desert, limited rainfall and high temperatures result in a natural water supply of under 200 cubic meters per person each year. Despite relying heavily on desalinated seawater and limited groundwater, inland and coastal water bodies in the region play a crucial role in preserving biodiversity, cultural heritage, economic prosperity, groundwater replenishment, and climate regulation. Understanding their pivotal significance provides essential guidance for managing water resources, particularly for sustainable development in arid areas like the UAE. Hence, effective preservation and management of scarce freshwater resources become imperative. Remote Sensing (RS) and Geographic Information System (GIS) have emerged as essential tools for assessing, monitoring, and analyzing water resources. Their advanced capabilities enable robust evaluation of land surface resources and facilitate comprehensive analysis of their temporal changes. This study conducts a detailed multi-temporal analysis of inland and coastal water bodies within the current land borders of the UAE using satellite imagery and GIS techniques, incorporating machine learning algorithms and supplementary datasets to enhance the classification process. Collectively, the presence of inland and coastal water remains minimal, fluctuating from 365km2 in the early 1970s to approximately 154 km2 presently. The analysis reveals an overall decline in water within the study area, although some new inland water bodies have emerged while coastal water has diminished. This study sheds light on the spatiotemporal dynamics of inland and coastal water bodies that fall within the existing land borders of the UAE, providing valuable insights to aid in planning and decision-making for sustainable development actions.