Water Resources Management and Sustainability

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

Acquiring vector feature layers such as surface water bodies from high-resolution remote sensing (HRRS) imagery has gained growing scientific interest worldwide. Thus, several strategies, technologies, techniques, and methods were designed and developed in order to delineate surface water bodies from remote sensing imagery varying in spectral, spatial and temporal characteristics. This research puts forward an intuitive method to extracting the surface water bodies from multispectral high-resolution drones and satellite imagery using an integrated deep learning method for GIS modeling in Dubai Emirate. In this research, training data was extracted first. Then, an advanced object detection model based on deep learning is introduced. Next, the implementation of this model in several areas across Dubai Emirate is comprehensively evaluated, including detection, recognition, classification, counting, and quality assessment. At the end, recommendations and limitations are summarized. The final evaluation tests performed comparing the produced outputs to the reference data suggest that higher accuracy for surface water extraction is accomplished from the multispectral high-resolution images than traditional approaches such as machine learning (Supervised classification) and photo interpretation. Overall, in urban areas, the average accuracy reached 98% while it reached 99% in rural areas, respectively. This novel method offers great opportunities for the Department of Geographic Information Systems Centre (DGISC) at Dubai Municipality, under multiple land-use scenarios, to optimize and limit the extremely heavy amount of expensive human labor responsible for editing the records through field surveys or photo interpretation or other manual techniques.

In the hydrologic literature, to model water flow in unsaturated soils, the Richards equation is usually applied, allowing the main components of the hydrologic cycle, as rainfall partitioning into surface runoff and infiltration, to be determined. The Richards equation is highly nonlinear, making it very challenging to derive analytical solutions. Recently, for constant rainfall intensity, under the simplified hypothesis of gravity-driven infiltration, and by assuming a capacitance framework, a simplified solution of the Richards equation that considers the Brooks and Corey hydraulic conductivity function, was suggested. By maintaining the assumption that the infiltration process is dominated by gravity, the objective of this paper is to relax the capacitance sketch applied to only one reservoir, by replicating the internal water content travel times through the discretization of the soil profile into multiple tanks connected in series. First, the previous analysis is briefly summarized, which is useful for the further developments. Then, for a fixed soil pore connectivity index (c = 0.5), which could be assumed for sandy soils, the same approach is extended to multiple non-linear reservoirs to model water balance components, achieving more reliable conditions. The presented approach could be not affected by uncertainty, since it is simply hydraulic, provided the hypotheses c = 0.5 and the assumption of a gravity-driven infiltration are satisfied. The suggested solution was compared with that derived by the Richards equation (via Hydrus-1D), where the gravity-driven hypothesis is relaxed the effect of the number of reservoirs was analyzed, and applications for both constant and time-variable rainfall intensity were performed.

Typhoon Ulysses (Vamco) brought about more than 300 flooding incidents in the Philippines in November 2020. The Cagayan Valley Region was reported with the highest worth of damage to infrastructure and agriculture. In this study, synthetic aperture radar images were used to analyze the effect of Typhoon Ulysses in the region. The VV and VH bands of Sentinel 1 were used to detect the flooded areas before (November 1) and after (November 13) the typhoon. The VH band was found more effective at detecting flooded and agricultural areas (72,722.30 ha and 37,736.70 ha, respectively) than the VV band (69,501.12 ha and 35,606.59 ha, respectively). The VV polarization was found to be more suited for monitoring vegetation, whereas the VH polarization is more suited for estimating flood extent, as based on the backscatter intensity of the two polarizations before and during flooding on representative places. The significantly high amount of rainfall (200–300 mm) received, low elevation and slope of the affected areas, and the volume of water released from Magat Dam were noted as the contributing factors to the massive flooding event. More than 35,000 ha of rice areas were flooded in Alcala town. Results showed that the standing crops I n Alcala increased after the typhoon (from 660.55 to 923.16 ha) when the flood subsided. This was determined using MODIS, Sentinel 1 and 2, and a 0.3 NDVI threshold. It was also noted that before the typhoon, most of the rice crops were at a stage of maturity and were ready for harvest a few days later.

In terms of economic damage, flood is the number one natural disaster in Australia. Extremes of floods and droughts are becoming more frequent now-a-days in Australia. Impact of climate change and anthropogenic activities on hydrologic catchments are assumed to be the driver of these changes in flood extremes. Design flood estimation is an established method used worldwide to minimise flood risk and in hydraulic design of different types of infrastructures. Annual maximum flood (AMF) data are widely used for designing flood estimation and flood risk assessment. In design flood estimation these AMF data are assumed to follow stationary assumptions i.e., all flood events result from same climate condition (homogenous) and all events are independent. In the context of climate change this assumption can be grossly violated. Investigation of trends in AMF data is the first step to understanding long term changes in flood data. This research study analysed the characteristics of trends in recorded AMF times series data. The selected study area is New South Wales (NSW) state of Australia. Initially 176 stream gauging stations are selected where the minimum record length of the AMF data in each station is 20 years. After visual and statistical data quality check, 36 stations are finally selected. The minimum and maximum record length of AMF data of these stations are 50 years (1971–2020) and 91 years (1930–2020), respectively. As stream flow have strong natural variability with large-scale periodic behaviour of climate, higher record length as considered in this study to captures multiple and long-term climate variability cycles whereas a shorter record length may provide misleading trends in AMF data. As catchment’s hydrologic behaviour may change significantly with the increase of catchment size, therefore all stream gauging stations are selected with maximum catchment area below 1000 km² spreading over flood plains, mountainous and coastal regions of NSW. The widely used non-parametric Mann–Kendall (MK) tests are used in this study to detect statistical trends. Trend tests are conducted with 5 and 10% significance levels. The MK test result shows significant trends in 14 station’s AMF record at 10% significance level, and in 9 stations with 5% significance level. The study shows that at 10% significance level, 39% of the selected station’s AMF series have significant trends. The study also shows that the average AMF in these 14 stations has decreased by a minimum of 4% to a maximum of 64% with an average decrease of mean by 39%. To investigate the behaviour of statistical parameters and trends in AMF data with different time ranges, AMF data series of each station is divided into two sub-series with two equal periods of record. The linear trend of each sub-series is plotted, and the mean, standard deviation and skewness of these sub-series are calculated. It is found that the statistical properties between two periods have been changed with significant decrease of mean and standard deviation in the second period of the data which is a violation of the stationarity assumption of AMF data used in the flood frequency analysis (FFA). The study also shows a general downward trend (without considering significance level) in the AMF data exists in 32 stations of the selected 36 stations. This study results suggest that there exist decreasing trends in most of the station’s AMF data in NSW and stresses the importance of adopting non-stationary FFA for design flood estimation in NSW.

Difficult to prevent floods from happening, but it is possible to prepare for it. The knowledge of flood phenomena, their genesis and their operation are the starting point in risk management. In Morocco, the floods are characterized by the rising of water, which constantly causes more and more damage. Many, areas have been deeply affected by this type of hazard, causing particularly significant damage. It is located in the great basin of Oum Er-Rbia (second largest basin on the scale of Morocco). The srou catchment covers an area of 1371.93 km², it is part of the friable Triassic formations of the eastern depression of the plateau central foot of the middle Atlas. It is equipped with two hydrometric stations, El Heri and Chacha namelleh. The altitudes are between 2195 and 670 m. This basin is subject to harsh climatic conditions marked by high precipitation aggressively concentrated and irregular in time and space. This paper aims to characterize the flash floods recorded over the 1971–2015 period, with a focus on the spring flood of 2010. The main objective is to understand the course and behavior of this flood. To do this, we propose a range of hydrological methods for the study and analysis of this important flood.

The rainfall patterns are no longer stationary due to changing climate. The non-stationary extreme rainfall resulted in the high flood risk in the urban area such as Surat city. In the current study, non-stationary extreme rainfall of Surat city is analysed using 68-years (1951–2018) observed daily rainfall data. Total five (physical processes) covariates namely, Local temperature anomaly (LT), Global temperature anomaly (GT), IOD-Dipole mode index (ID), ENSO-Sea surface temperature Index (ES) and Time is used. Firstly, the stationary Generalised Extreme Value (GEV) model is developed using extreme daily rainfall. Secondly, non-stationary GEV model using location parameter is developed with aforesaid covariates. Thirdly, non-stationary GEV model using location and scale parameters are developed using aforementioned covariates. A total of 27 GEV based models are developed and the significant covariate and best non-stationary model for extreme precipitation is evaluated using likelihood ratio test. Out of 27 constructed GEV models 13 models are showing significant effect of covariate on extreme precipitation analysis. The combination of LT-ES based GEV model using non-stationary location and scale parameter gives the best model with lowest AIC, and extreme daily rainfall for corresponding return levels are compared with stationary GEV model. The 2-year, 5-year, 10-year, 25-year, 50-year, and 100-year return period extreme daily rainfall are 146 mm (162 mm), 200 mm (247 mm), 235 mm (305 mm), 283 mm (381 mm), 319 mm (440 mm), and 356 mm (500 mm) respectively for GEV stationary (Non-stationary LT-ES) model for the Surat city. Moreover, the trend analysis using Modified-Mann Kendall (MMK) test and Innovative trend test analysis (ITA) shown the non-significant increasing trend in the extreme daily rainfall for Surat city. The current study can be useful in designing hydrologic infrastructure of Surat city under changing climate.

Meteorological drought is a natural phenomenon whose probability and frequency of occurrence increases with increasing the global air temperature. Over the last 138 years, the average annual air temperature in Slovakia has increased between (1.7 and −1.8 °C). This paper presents the analysis of drought in the eastern part of Slovakia using Standardized Precipitation Index (SPI) computed in 12 and 24 months’ time scales for classification of historical drought events for the period (1972–2014). The analysis was done at four precipitation stations localized in sub-catchment Bodrog that situated in the Eastern part of Slovakia. Then, the RUN method was used to identify extreme drought event. SPI value less than (−2) indicates drought condition. A one-dimensional frequency analysis of drought risk was performed in order to determine the probability of its occurrence and evaluating the negative effects of long-term precipitation deficits on surface and groundwater levels, aquatic fauna and flora. The results showed that the year 2003 was a significant year in which extreme meteorological drought was recorded at all precipitation stations. The most vulnerable area with an extreme rainfall deficit is the area in the middle of Bodrog basin, where meteorological droughts can rarely be expected, but can persist for a longer period. This methodology can be applied in different locations of the world as it is considered a broad methodology for drought analysis that based on the availability of data at certain locations.

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

Monthly flow data from a single hydrometric station in our study area (Tizi Nisly) was used and covers the period from 1976 to 2018.

Water table depth is declining in most parts of the world, especially in those countries which have high temperatures almost throughout the year and receive very less precipitation throughout the year. Due to increasing population and intensive agricultural and industrial practices, the demand of freshwater is increasing and is predicted to increase in upcoming years. The countries which receive less rainfall throughout the year have limited groundwater recharge, resulting in declining of water table. United Arab Emirates belong to this category of countries where there is high temperature almost throughout the year and receives very less rainfall (less than 200 mm annually). Modeling groundwater in such an arid climate is of serious concern. This paper proposes LSTM models for prediction of water table depth at six different wells in different parts of United Arab Emirates. Data obtained for this study comprises of times series monthly water table depth data in meters from ground level from six different wells. Analysis of the data showed the drastic decline of water table depth between 1977 and 2011. These data were used to generate the input and target variables by adding three time-step lags in the given data. The time-step lag data was used as input to predict the current water table depth. In other words, the water table depth data of current target month was predicted using the previous three months water table depth data as input. Training of LSTM models was carried forward utilizing Python platform as a programming language library (TensorFlow). The trained models provided good accuracy in testing dataset. The training R² values of all the six models were more than 0.96 and the testing R² values of all the six models were more than 0.91.

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

Availability of groundwater has been largely impacted by climate change worldwide, especially in arid and semi-arid areas where water is limited. In arid and semi-arid areas, which are heavily rely on groundwater to meet their water demands, there is a high risk of excessive use of groundwater, particularly during successive dry periods. This paper aimed at assessing changes in groundwater levels due to seasonal and annual variations in precipitation when storage of groundwater aquifers is largely depending on the amount of precipitation. Erbil province in Iraq was chosen as a representative example for many arid and semi-arid areas that suffering from overexploitation use of groundwater resources. Climate change has contributed to increase the pressure and stress on the availability of groundwater and increases environmental concerns. In this work, the long-term falling of groundwater levels is also examined. Monthly records of groundwater level between January 2004 and January 2016 observed at 54 observation wells in Erbil were assessed. Findings revealed that nearly 91% of the observation wells are associated with a drop in groundwater level, the remaining 9% were linked to steady or slight rising in groundwater level. Approximately 50% of those linked to a fall in groundwater level is associated with a significant drop (> 1.73 m/year), and 24% are linked to moderate drops (0.58 m/year ≤ drop ≤ 1.73 m/year), whereas the remaining 26% relate to low falls (< 0.58 m/year) in groundwater level. The slopes of groundwater level fall between 0.005 and 0.32, with a mean of 0.11. The outcomes of this study would support the decision makers and water managers to sustainably manage groundwater in the study area and other similar areas. Moreover, the study represents an important step towards launching nation-wide groundwater assessment programmes to achieve sustainable abstraction and rational utilization and management of groundwater resources.

Groundwater resources are of utmost importance in arid regions due to the scarcity and non-availability of surface water sources. Applications of geo-modeling integrated with machine learning and artificial intelligence algorithms are rapidly advancing for the sustainable management and conservation of those resources. In this pilot study, we explored the state-of-the-art ANN technologies as innovative techniques in a geo-modelling framework for the prediction of changes in groundwater level of part of Al Ain city, United Arab Emirates (UAE). We used Fill Forward Padding to fill the data gaps and utilized the state-of-the-art ranger optimization algorithm to find the most accurate model that suites our data. The model takes 8 inputs to produce the predicted groundwater levels. Training the model on the data gave the highest accuracy in the 408th epoch, through the following hidden layer configuration [700, 200, 600, 100, 9]. To fill the spatial gaps between the wells we made use of Ordinary Kriging utilizing the Circular semi-variogram model. The built model produced predicted variability in groundwater (2013–2019) based on the observations (2004–2012), thereby strengthening the future use of the system in machine learning. Results and observation data highlighted moderate variability in groundwater levels through 15 different annually averaged maps. These variations are attributed to both natural and anthropogenic factors. Indeed, extensive abstraction, changes in precipitation rates, population growth and urbanization strongly contributed to and controlled the groundwater fluctuations and level variability during the study period throughout the region.

Groundwater is a vital source of potable water in arid and semi-arid regions, yet groundwater cannot be used in many areas due to increasing groundwater salinity. Aquifer Storage and Recovery (ASR), a managed aquifer recharge technique, is used for excessively available freshwater storage within the saline subsurface for its future recovery. The performance of ASR in the saline aquifer is adversely affected by mixing injected freshwater with ambient saline groundwater. The aquifer hydrogeology and salinity level of ambient groundwater control the mixing phenomena during storage. Therefore, site selection for an ASR scheme in any region needs appropriate aquifer properties to ensure the project's success. This study’s main objective is to determine hydrogeological parameters’ role in the performance of ASR in terms of recovery efficiency using the saturated variable-density flow model (SEAWAT). The model was simulated with varying aquifer properties to optimize different influencing factors. According to the findings of this study, the low hydraulic conductivity and hydraulic gradient in thin aquifers with low longitudinal dispersivity favor ASR performance in salt-affected regions. Transverse dispersivity and aquifer porosity have a minimal and indirect effect on recovery efficiency. This study’s findings will significantly impact the ASR scheme’s site selection procedure and overall performance.

This paper estimates groundwater resources in four groundwater bodies shared between different planning areas, specifically the hydrographic basins of the Segura and Jucar rivers that transit entirely within the Spanish State and flow into the Mediterranean Sea. Three of these masses are overexploited, while the fourth has increased its resources thanks to the excess irrigation that is carried out mostly with surface water. This comes from a transfer that takes place between the Tagus and Segura rivers. Given that Spanish legislation considers that the recharge of an aquifer is assimilable to groundwater resource. These have been determined, both for the undisturbed state (without pumping) and for the disturbed (with pumping and irrigation returns) by means of the code RENATA. The calculations have been made not only from the perspective of the watershed divide, but also from the point of view of the groundwater divide. The results that have been obtained have revealed a remarkable and significant casuistry. In this regard, it should be noted, among the conclusions that have been drawn, that the concept of groundwater divide makes sense to use it only when aquifers discharge water into the surface hydrographic network or into the sea, since when aquifers are overexploited and springs and groundwater discharges to rivers have dried up, the notion of recharge as a renewable resource does not make any sense, since the recharge that takes place in the aquifer only contributes to alleviating or palliate the consumption that is being made of its reserves.

Nowadays, the advancement towards the need of employing renewable energy sources to generate electricity has gained several attentions in the desalination methodology. Concentrated solar thermal is one of the thriving net-zero approaches to heat the brine water during desalination technique due to its least cost and eco-friendly methodology. In this work, tapping of concentrated solar energy employs a solar receiver that is modelled based on a microchannel heat exchanger. This study involves a parametric analysis on different operating and geometric metrics of the heat exchanger conducted over the Reynolds number ranging from 50 to 1500. This study employs water to be utilized as working fluid while aluminium alloy is taken as the substrate material. The hydraulic and thermal performance of the microchannel heat exchanger is computed in terms of total thermal resistance, heat transfer coefficient and pumping power. The results indicated that irrespective of any change in the geometric parameters, the rise in Reynolds number alleviates and escalates total thermal resistance and pumping power respectively. Also, the effect of decrease in hydraulic diameter of the microchannel generates significant reduction in both thermal resistance and pumping power. In addition, the decrease in microchannel length contributed to better heat transfer performance.

According to recent estimations, the UAE’s fresh groundwater resources are extremely limited and have a very short shelf life if things continue as they are. With and without augmentation, the total recharge to the Quaternary aquifer is 1197 and 1001 MCM, but the annual total groundwater extraction is greater than 2860 MCM. In agricultural areas, it also revealed that the quaternary aquifer’s replenishment ratio ranges from 1 to 40%. Even though this is a general conclusion, it is necessary to approach groundwater resources in each region in a unique way. Implementing the required regulations is important to alter the current practice and give water based on the crop’s water needs. Contrarily, brackish groundwater is plentiful when compared to fresh groundwater. Around 200 BCM is a reservoir of brackish groundwater with a salinity of less than 15,000 mg/l. When used for agriculture development, this type of water should be treated as a precious resource and conserved. To identify the groundwater potential zones, all of the thematic maps were overlaid using the spatial analysis tool in ArcGIS 10.3. By using the AHP approach, the groundwater conditions in the farming areas in UAE were categorized into six groundwater potential zones (GWPZs)) based on the groundwater reserve, overall salinity, distance to existing farms (pumping wells), ratio of the present saturated thickness/max saturated thickness, and remaining lifetime. According to the results, the groundwater potential zones 1 and 2—which have TDS levels less than 2000 mg/L and between 2000 and 5000 mg/L, respectively cover areas of 40 and 50 km². In GWPZ1 and GWPOZ2, the estimated groundwater reserves are 581 and 640 MCM, respectively. Medium (5000 TDS–10,000 mg/L) and highly brackish (10,000 TDS–15,000 mg/L) groundwater potential zones, respectively, span 934 and 913 km². Zones 3 and 4 have a total groundwater reserve of around 28,000 MCM, demonstrating their critical role as the only inland source of irrigation water with preventative desalination. In general, the area of arable lands and the available fresh groundwater resources are very limited.

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

Change of climatic conditions certainly cause several eco-environmental complications which includes variations to the water circulations systems. Climate change effects on groundwater generate complications in the drop of groundwater resources, harshness of droughts and floods, deployment of contaminants as well as salt-water invasion. Population increases and sponsored electricity for irrigation practices has exhilarated population especially living in the rural areas lift additional groundwater from deeper aquifer for irrigation resulted severe depletion of groundwater in several parts of Indian subcontinent. The groundwater dependency for various purposes has enhanced number of deep well construction in the successive years led to the groundwater depletion. The rapid urbanization activity and greed of human beings ultimately indication to the shrinking/disappearing of natural water bodies in many towns and cities of India which led to the continuous decline of groundwater levels in Tirupati and Delhi urban environs. Because of fast decline of groundwater levels in the mega city of New Delhi because of rapid urban activities, recharge ditches were constructed to collect rainwater from the rooftop and surface channels. Harvesting of rainwater permit improvement of the groundwater in the ephemeral rivers and the stoppage of salt-water invasion into freshwater regions. These harvesting structures will develop groundwater amounts which ultimately boost irrigation practices. The available high base flows (~3000 Mcft) in the ephemeral Swarnamukhi River could be obstructed at appropriate sites by the construction of sub-surface dams to rise groundwater levels in the surrounding wells. The impact study in piezometric wells situated near subsurface dams indicate an increase of around 1.45 m of groundwater levels in the adjacent filter wells. The public participation is utmost important in the maintenance of local artificial recharge structures for the sustainable water resources development and management.

Soil erosion is a challenging worldwide environmental issue since it entails many environmental problems such as fertility loss and water pollution. Prioritization of watershed prone to soil erosion is cornerstone in any effective and sustainable management program of natural resources. Morphometry is a powerful tool that has been extensively used for this purpose. This study presents a combination and integration of two different soil erosion prioritization methods that were applied to Yarmouk River Basin (YRB). The methods of morphometric analysis and the Land Use/Land Cover (LULC) analysis were compared for erosion prioritization. The YRB was divided into 44 sub-watersheds. Twenty-one morphometric parameters were extracted and ranked based on their values and relationships to calculate the compound factor (C_f), which was used to prioritize sub-watersheds in terms of sensitivity to soil erosion. It was found that YRB is a fifth-order drainage system, with a dendritic drainage pattern and elongated shape. Morphometric analysis resulted in categorizing about 41% of the YRB in the high and very high soil erosion susceptibility zones while the LULC analysis LULC revealed that 88.6% of the basin was classified as having high-very high susceptibility to soil erosion. The sub-watersheds 1, 3, 4, 7, 9, 10, 11, 14, 20, 27, 28, 30, 32, 33, 35, 36, and 40 were found the most vulnerable to soil erosion based on both methods of analysis.

Samples of leachate from the Osisioma open dumpsite and water from four boreholes from the surrounding residence were collected using the four cardinal point model. The sampled boreholes were assigned BH 1, BH 2, BH 3, and BH 4 with distances of 80, 251, 348, and 455 (m) respectively from the location of the dumpsite which is at the center as regards to the cardinal point model used. Physicochemical and microbiological parameters were analyzed to determine the quality of the water. pH, Conductivity, Temperature, TDS, Colour, alkalinity, DO, BOD, COD, Nitrate, Nitrate-Nitrogen, Iron, Chlorine, Chromium, Copper, Arsenic, Lead, Zinc, total bacterial count, E. coli and total coliform count were analyzed. pH ranged from 5.2 to 6.3 in borehole water indicating toxic pollution and was neutral (7.1) in the leachate sample. The temperature of borehole water and leachate ranged from 26.70 to 29.70 °C, Colour (Platinum Cobalt Unit) ranged from 13 to 13850PCU in borehole water and leachate. The concentrations of, Lead, Chromium, Copper, Nitrate, Chlorine, Zinc and Iron ranged from; Lead 0.001 in BH 3 to 0.125 in BH 1, Copper 0.00 in BH 3 to 0.08 in BH 4, Chromium 0.014 in BH 3 to 0.037 in BH 2, Nitrate 234.2 in BH 4 to 343.0 in BH 1, Chlorine 0.35 in BH 3 to 1.71 in BH 4, Zinc; 0.09 mg/L in BH 3 to 0.25 in BH 4 and Iron 0.19 in BH 3 to 0.42 in BH 4 respectively. Alkalinity in water sample was below the WHO permissible limit. Arsenic and Iron were above the permissible limits in BH 1 (0.031 and 0.40 mg/L) and BH 4 (0.020 and 0.42 mg/L). Lead also exceeded the limit in BH 1 at 0.125 mg/L. DO, nitrate, nitrate-nitrogen and chlorine exceeded the limits across all the boreholes water sampled. In the microbiological analysis, Total Bacteria Count, E. coli, and Total Coliform Count were analyzed with mean values of 62.00, 6.50 and 23.75 respectively. All the microbial parameters analyzed exceeded WHO permissible limits which make the water unfit for direct consumption. The variations in concentration of microbiological parameters were in respect to distance from the dumpsite and elevation of the sampling points. There is therefore a need for major water treatment to be carried out on the borehole water before human consumption. Dumping of fresh refuse in the study area should be discouraged with the use of sanctions and fines on defaulters. Government should adopt eco-friendly solid waste disposal management systems such as sorting before disposal, incineration, landfill, waste conversion to biogas and compost as well as provision of portable water to reduce indiscriminate borehole construction to preserve the soil structure.

The application of statistical techniques for the study of groundwater data provides an authentic understanding of aquifer and ecological condition and leads to the recognition of the potential sources that determine the groundwater system. The groundwater quality data generated was analyzed using Principal Component Analysis and Cluster analysis. Principal Component Analysis result yielded five principal factor which accounted for 78.69% total variance dominated by Total Hardness, Total Dissolved Solids, Cu, Cl⁻, NO₃⁻, Cu, Electrical Conductivity indicating that the major variations are related to human actions and natural processes. Cluster analysis grouped the 20 boreholes into four statistically substantial clusters.

The High Valley of Medjerda characterized by a semi-arid climate and a strong relief, suffer from an intense erosion contributing to the sediment deposit in Dams. The percentage of sedimentation in Mellegue and Sidi Salem Dams are 81 and 29%. In this paper we analyzed the factors contributing to the siltation of Sidi Salem dam, assessed the dam siltation by PISA (Previsioni Interimento Serbatoi Artificiali) model. To study the spatio-temporal variability of precipitation, time series of rain were collected from 16 rainfall stations, ranging from 1980/81 to 2014/15. The missing data were reconstructed using the weighting method. The breaks in the pluviometry series detected by homogeneity tests (Pettitt, Buishand and SNHT) which make it possible to study the distribution of the pluviometric regime on the monthly and annual scales of the watershed with 5 stations that have fewer breaks compared to the others. The average annual rainfall determined by spatial interpolation with the method of Theissen is 477 mm. The sensitivity study of PISA model brought out that the eroded area (which depends on the area of the watershed and land cover) has a significant influence on the rate of sedimentation compared to the other parameters. Then we proceeded to assess the soil losses in the sub-basins (numbered 7) after determining the specifics parameters. By adding up the siltation indices of each sub-basin, we obtain a cumulative sedimentation rate equal to 415 Mm³. This result is overestimated by 2.45 times compared to the bathymetric survey (169 Mm³).

Agricultural activities in arid regions, like Kuwait, require large volume of water for irrigation purposes. Saline groundwater quality, shortage in treated wastewater supply, and expensive freshwater force farmers to use on-site brackish groundwater reverse osmosis (RO) units to treat brackish to saline groundwater. One of RO units’ primary limitations is the large volume of concentrated brine (reject water) that is generated from these units. Due to the absence of proper policies and regulations to handle reject water from RO units, it is often disposed of illegally over open land surface or unlined pits. Concentrated reject water could have negative impacts on groundwater quality, and uncontrolled pumping of groundwater could affect groundwater levels. Soil salinization due to brine disposal has negative impacts on crops, threatening partial food security attempts of the authorities. The study presented here has been conducted with the objective to assess the impact of RO reject brine on groundwater quality and levels in agricultural farms of Kuwait. This paper presents the initial activities and results of the study to evaluate impacts of RO reject water on groundwater quality and levels and recommend rational utilization of available water reserves for agricultural purposes. Groundwater levels and salinity were measured, and first round of sample collection was carried out from groundwater wells serving the feed water for RO units, product water and reject water from RO units. Samples are analyzed for major ions, trace metals and nutrients. Groundwater levels are regularly monitored to evaluate their fluctuations. Initial results indicate the decline in groundwater table and quality deterioration over the period of time. Preliminary data of this ongoing study and future plans is discussed in this paper.

The development of an optimization model for planning regional wastewater systems is centered on reducing the overall costs of wastewater treatment plants (WWTP) locations and sewer layout while taking treatment capacity uncertainty into account. The goal of the model is to reduce overall costs while taking uncertainty into account, with a given degree of reliability, ensuring that the amount of flow to be treated does not exceed the treatment capacity. The model is formulated using a chance-constrained method which have been used for addressing optimization problems with a range of uncertainties. The model is developed in the General Algebraic Modeling System (GAMS) program using Mixed-Integer Linear Programming (MILP), and it is then applied to a simple example utilizing various reliability percentages ranging from 60 to 95%. A simple example demonstrates that employing 60–75% reliability has the same total costs and layout for the system. The system’s layout and overall costs would be higher although, as the reliability value exceeds 80%.

The world population continues to increase while the water resources required to cater to this population are not increasing in proportion. In light of factors such as lack of availability of fresh water, depletion in groundwater levels, land pollution impacting water sources, high financial and environmental costs associated with water desalination, climate change effects and the list goes on, water stress is only expected to increase globally which calls for measures to manage this resource even more carefully. A significant increase in urbanization is further adding to the pressure with buildings being a major contributor to the water consumption footprint. If we are to break down the water use in buildings, a major part of this could be attributed to cleaning activities. The main objective of this work is to identify opportunities to reduce water consumption in buildings through the optimization of cleaning cycles. This would have other desirable side effects in the form of a reduction in operational costs as well as a corresponding positive impact on the environment achieved through the reduction in the use of chemicals and reduced CO₂ emissions resulting from less water use. To accomplish these objectives, we present a cyber-physical system called ‘Dew’. Dew is made up of a hardware device and the necessary software system. The hardware device comprises sensors connected to a microcontroller platform. One of the sensors passively tracks (in a privacy-preserving manner) visitors to washroom facilities and makes this data available at a backend system. Such data when analyzed yields insights that are then leveraged for decision-making to reduce the number of cleaning cycles. Details of the ‘Dew’ system are provided in this article. In particular, we highlight the design and implementation of the proof-of-concept solution, a small-scale pilot trial carried out on our university campus, and the findings from this study that throw light on the potential of this solution. These findings support our hypothesis that the Dew system can reduce water wastage, reduce operational costs, and can bring about a positive impact on the environment. In the small-scale study we conducted, we observed the potential for savings as high as 50% for two locations and 30% on average over the three locations considered in this study. This shows the promising potential that exists for scaled-up deployments over a large number of buildings over a prolonged period. In addition to water and monetary savings, Dew also has the potential to be used as an aid in tracking and contributing to sustainability-related metrics.

Climate change and variability are arguably one of humanity’s most significant challenges. Developing countries in Sub-Saharan Africa (SSA), such as Ghana, are uncertain and at risk, because temperatures in SSA are rising faster than the global mean temperature. These countries are also more vulnerable because they mainly depend on agriculture, the most climate-sensitive sector. The Volta River Basin (VRB) is an essential transboundary basin in West Africa that covers about 410 thousand square kilometers across six countries. These countries are Benin, Burkina Faso, Côte d’Ivoire, Ghana, Mali, and Togo. Its natural resources sustain the livelihoods of its population and contribute to economic development in Ghana and neighboring countries. This study investigates climate change impacts and adaptation strategies to optimize resource use in the VRB. Cli-Run, Cli-Crop, and Impend models simulated dry and wet climate change scenarios, river basin modeling of hydrology, and cropping systems. This study presented several adaptation scenarios’ results relevant to the water and agriculture sectors. These adaptation measures are a high priority for short and long-term adaptation to climate change. In the various Ghana agroclimatic zones, the construction of more dams for irrigation projects and sub-surface water storage is identified as necessary for sustainable water management. Measures rated high priority include monitoring systems, managing water resources more efficiently, and identifying specific crop/livestock adaptation needs suitable for various agro-ecological zones. Other measures include constructing small to mid-size irrigation dams, improving the land tenure system, promoting agribusiness and entrepreneurial skills to generate off-farm income, and improving access to loans and microcredit. Climate adaptation practices are needed at the strategic national and regional levels to assure wider stakeholders’ participation and be more resilient against climate change.

Jordan is heading towards a serious water crisis, facing a freshwater deficit of about 712 million m³ per year by 2050. Seawater desalination is the only suitable option to mitigate water scarcity in the region. However, Jordan has only a short coastline at Aqaba in the South, at a great distance to the demand center Amman in the North. Therefore, transboundary water production and transfer (WPT) strategies are essential. In this respect, Israel and Jordan have recently signed a declaration of intent (DoI) to intensify their cooperation through freshwater supply in exchange for renewable energy. This article assesses and discusses the feasibility and economic viability of a water-energy SWAP between Israel and Jordan, based on the results from the SALAM II initiative. The following steps were taken: (1) identification of alternative sites for seawater desalination (SWD) on the Mediterranean coast of Israel, (2) identification of optimal routes for water transfer between the SWD-plants and demand centers, (3) selection of promising strategies for water production and transfer, (4) selection of options for renewable energy production by photovoltaics in Jordan, (5) analysis of energy transfer to Israel. This article indicates that doubling the SWAP capacity compared to the recently signed DoI by Israel and Jordan will be necessary by 2050. In addition, a promising bartering strategy consists of the water production and transfer of 400 MCM/y freshwaters from large-scale SWD North of Haifa Bay in exchange for 12.8 TWh/y in renewable energies produced in Jordan. Installing a 5.8 GWp PV plant with an area of ~ 72.9 km² in the Disi area in Jordan could provide the necessary energy production for such a SWAP concept.

The extreme scarcity of water resources in arid regions necessitates developing effective and adaptive long-term plans that maximize the economic value of these resources. To support these efforts, the author developed the Hydroeconomic Groundwater Model for Arid Regions (HGMAR) which offers an interactive simulation environment for managing scarce groundwater resources. HGMAR estimates the costs and benefits of extracting groundwater from a multi-salinity aquifer system composed of several zones each representing unique hydrogeological characteristics and types of water use. Multi-salinity is represented by modeling the aquifer as a stack of groundwater layers, with a fresh groundwater layer underlain by a brackish groundwater layer, which in turn is underlain a by saline groundwater layer. HGMAR features an interactive user interface that provides access to several hydrogeological and economic parameters to formulate alternative groundwater management schemes and produce projections of groundwater levels and net present values (NPV). The paper presents the application of HGMAR to groundwater resources in Abu Dhabi, UAE.