Advances in Sustainable and Environmental Hydrology, Hydrogeology, Hydrochemistry and Water Resources

Currently, water demands throughout the world exceed the ability of Earth’s natural hydrologic cycles to replenish adequate fresh supplies of this resource. Water must, therefore, be recycled and reused many times over the course of each period between its extraction from, and return to, those cycles. Some governments have already issued large-scale programs to recover and reuse treated municipal waste waters, rehabilitate saline and contaminated wells, desalinate brackish- and sea-water sources. In the last years, membrane operations have been assigned a key role in water reclamation schemes that are aimed at higher water quality reuse applications. In the present work, membrane operations in the field of water treatment are discussed.

Drought is considered a looming catastrophe for socioeconomic development. In recent decades, Cambodia has been affected by increased severity of drought. Since drought is a slowly evolving natural disaster, its negative impacts can be mitigated through monitoring and characterizing drought levels by assimilating data from one or several indicators into a single numerical index which is more readily usable than raw indicator data. This study performed a comparative assessment of three meteorological drought indices including Standardized Precipitation Index (SPI), Effective Drought Index (EDI), and Percent of Normal Precipitation (PNP) for the Baribo basin in Cambodia. The SPI, EDI, and PNP are generally able to be used for assessing drought severity and duration but with a slight difference in performance. The SPI is considered the best index for capturing the extreme and severe drought events, while the EDI is a cautious index for assessing drought duration. The Baribo and Kraing Ponley sub-basins located in the middle and southern parts of the entire Baribo are considered the drought-prone area.

Reliable precipitation forecast is one of the key inputs to generate accurate and reliable hydrological forecast. This paper uses the North American Multimodel Ensemble (NMME) models to generate seasonal precipitation forecasts in Indonesia. The NMME models are verified against observed precipitation, and the analysis shows that they are biased and underdispersive. The Bayesian Model Averaging (BMA) approach was applied to calibrate the forecast for reliable prediction. East Nusa Tenggara (NTT) is chosen as the pilot study since the region has been well recognized as a dry region with the highest degree of vulnerability toward drought. The results show that the BMA improves the forecast reliability. Moreover, the Canadian Meteorological Center (CMC) models outperform the others. The map of the forecasted Standardized Precipitation Index (SPI) is validated with the observation and shows a high prediction accuracy.

Changes in the historical rainfall and streamflow observations are important for understanding the climate change. The homogeneity of the annual and monthly times series of 9 rainfall stations and 3 streamflow gages, located at the Seyhan basin in Turkey, was examined using standard normal homogeneity test and Buishand test. The trend was studied by Mann-Kendall test, which is used for identifying the significance of the trend, and the Sen’s slope estimator, which provides the magnitude of the trend. Finally, the Pettit test was also applied on the annual time series only to obtain the most probable change year. The entire time series was found as homogeneous, although several significant p values were obtained in the 0.05 but not in the 0.01 significance level. The annual trend varied from one station to another but was found to be significant in one rainfall and one streamflow station at the 0.1 significance level only. Monthly time series was found to have the most significant trend in January at 0.05 significance level. Several months have no stations with a significant trend, while others have only one station with a significant trend. The Pettit test results showed no consistent change year through all the stations, although the most frequent change year obtained was for 1981.

The present study is an attempt to evaluate the spatial and temporal rainfall variability of the Medjerda High Valley on the hydrological response of the watershed. Mean time series were collected from 1980/1981 to 2014/2015 for 16 rain gauges covering the studied basin. Missing data were reconstructed using the ponderation method. Subsequently, breaks in each rainfall time series were detected by three tests: Pettitt, SNHT and Buishand’s using Xlstat software. These tests and the calculation of rainfall indices reveal an alternation of wet and dry episodes with very high rainfall excesses. Spatial interpolation of rainfall was conducted on an annual, monthly, and seasonal basis by three methods: Theissen polygon, Spline, and ordinary Kriging. The predicted mean precipitation of the Medjerda High Valley was used for the hydrological study. Thus, the variation of the contributions, their relation with the rainfall and their importance to the basin were studied via the hydrological model GR2m. The flow and, consequently, the water resources constitute the hydrological response of the watershed to the rainfall impulses.

Rainfall runoff conceptual models are used mainly to help make decisions in surface water resources and water quality management. The model calibration is an important step in selecting suitable sets of parameters. The model validation helps to demonstrate the model performance outside the calibration period, in extrapolation. Often, the calibration/validation of the model are carried out using the Generalized Split Sample Test (GSST) method. It is proposed to depict the validation analysis in view of the information gain between observed rainfall (mm day−1) and runoff (mm day−1). For illustration, we adopt the bucket bottom hole (BBH) model with a daily step. The model is lumped. The calibration is achieved by accepting the sets of parameters (solutions) that guarantee a relative error <20%. In addition, a Nash-Sutcliffe coefficient (NSH) condition is established with NSH >0.75. The evaluation of model performance in validation is based on NSH criterion at the monthly and decadal scales. The case study is the basin of the Sejnane River (376 km2) now controlled by a dam in northern Tunisia. It is found that the period with the highest information gain between rainfall and runoff observations constitutes a good “receiver” which means a good ability to reproduce runoff data regardless of the calibration period.

In this paper, the time and frequency-based methods as cross wavelet (XWT) and wavelet coherence transform (WCT) are used to search the links between rainfall and runoff of the hydrogeological systems of the Sebaou river watershed (northern central Algeria). The analysis shows a discontinuity in the linearity between rainfall and discharge that could correspond to the dry periods, storage during floods and the capacitance of the aquifer to store reserves, with the exception of some significant amplifications in some time intervals. Furthermore, human activities such as the dam construction and the smuggling of sands and rocks of the Oued (Wadi) since the year 1998 have had a significant impact on rainfall-runoff relationship, the flows decrease and the changes in the flow regime, which is more pronounced with a rupture in the annual component of 256–512 day of WCT spectrum.

This study is a new application of the recession curve analysis with a new non-subjective method. Its objective is to construct master recession curves generated by placing, horizontally, the vertex of individual recession segments of the most suitable connection line defined by measurement points of a preceding recession segment. This proposed methodology was applied for a rural catchment with a low urban contribution, namely Madjez Ressoul, which is located in the Ain Berda region in Algeria. The results of separation always give an appropriate R2 coefficient; they confirm the ability to calculate the recession curve coefficient k of the three processes (surface flow, subsurface flow and baseflow).

To assess the availability of water in a large agricultural region, the method of calculating the characteristics of water and heat regimes for vegetation seasons has been developed, using the physical-mathematical model of water and heat exchange between land surface and atmosphere (LSM, Land Surface Model), adapted to satellite data on land surface and meteorological conditions. The case study has been carried out for the part of the Central Black Earth Region (CBER) of 227,300 km2, located in the European Russia, for the vegetation seasons of 2014–2016. Methods and technologies of estimating vegetation and meteorological characteristics retrieved from the measurement data of the radiometers AVHRR/NOAA, SEVIRI/Meteosat-10, and MSU-MR/Meteor-M No. 2, as well as procedures of using obtained satellite-derived estimates in the model are briefly described. The results of simulation of soil water content, evapotranspiration, and other water and heat regime characteristics for the region of interest over the above vegetation seasons are presented. The results of calculating soil surface moisture using measurement data from the scatterometer ASCAT/MetOp-B are also shown.

Actual evapotranspiration (ETa) has a very important significance for hydrological and environmental purposes balance in arid and semi-arid areas. MOD16 product was applied to estimate seasonal ETa trends for 2000–2009 time period, in the Pallasovsky District of Volgograd Region, South-East of the European part of Russia. The result of time series computing by Mann-Kendall test code indicated that ETa in this study region decreased during the analyzed period. The speed value of this process gradually varies from 4.7 mm/year in the southern part with about 240 mm of annual average ETa to 17.3 mm/year in the northern part with about 375 mm of annual average ETa. Analysis of the seasonal spatial distribution of ETa trend over the study region shows that it is influenced by changes of precipitation during warm seasons, and as a consequence, by land cover degradation due to farming system changes.

Hydrology is widely used in the design of hydraulic structures. Knowing the exact value of the specific flow of the project is a permanent preoccupation of Civil Engineers. This is why we propose in this article a set of maps giving the frequency specific flows (return periods of 10, 50, 100 years) on the Sebaou watershed in Great Kabylia (Algeria). These cards will be basic tools for design engineers to evaluate the project flow required to design a hydraulic structure such as a small dam, a sewerage network or a storm basin.

The hydrochemistry in the Mishrif reservoir, located at the main productive oilfields at Basrah, southern Iraq, is discussed. Water chemistry coupled with boron isotopes (10B, 11B) were analyzed using ICP-MS and ICP-SFMS, respectively, and used to determine the subsurface fluid flow direction in the oil traps and interpret the rock-fluid interaction. The presence of boron in brine waters is useful in identifying the sources of water intrusive to oil wells. The δ11B ranged between 33.7 and 35.9‰ with an average of 35.4‰ in the studied oilfields which is lower than that in the Dead Sea (39–57‰), indicating a dilution by the present seawater and injection water. The potentiometric subsurface maps were modelled and super-pressure sites that are of great importance in the oil exploration were marked to pay attention to during future drilling.

Transient drainage equations presented earlier neglect the unsaturated flow above the water-table and assume constant drainable porosity. In this paper, a solution for the drainage problem is developed; it takes the unsaturated flow towards the drain into account and considers a variable drainable porosity. The solution is based on the spatial integration of the two-dimensional Richards Equation. The resulting integrated model is first simplified by applying Dupuit-Forchheimer (DF) theory and assuming a hydrostatic pressure distribution above the water-table, and then twice spatially integrated, yielding to a nonlinear differential equation for predicting the fall of the midway water-table height. With respect to drainage design, the developed equation, not presented before, provides a new method for designing subsurface drainage under transient conditions.

The Mediterranean semi-arid zones are characterized by irregular rainfall patterns in time and space. A statistical approach to the quantification of solid intakes has been developed in this study. The data used are collected at the Boukadir river watershed. The observation period covers 21 years (1993–2013). Maximum values for solid transport are recorded in early fall and late spring. The average annual sediment load recorded at the outlet of the watershed of Boukadir wadi is estimated at 17,666 ton, which corresponds to a specific degradation of about 220 ton km−2 year−1. It should be noted that this value is in the range of the degradations found for some Maghrebian watersheds with similar regimes.

The estimation of sediment transport has aroused our interest in this work because it is a liability to the conservation of the ecological environment and the protection of hydraulic structures against siltation sediments. The adopted methodology consists in (i) studying the evolution of the suspended sediment concentrations according to the water discharge, (ii) establishing a regressive model to explain the relationship between water discharge-sediment discharge, (iii) calculating the mean annual suspended sediment load and specific suspended sediment yield in the catchment area of the plain of Sidi Bel Abbès.

Al, Fe, Ti, Li, Zn, Pb, U, Sc, Sn, Bi, Zr, Ba, As, Sr, W, V, Co, Cu, Ni, Mo, Cr, Mn, Ba, Sn, Sb, Ag, organic (TOC) and carbonate (TIC) carbon contents in suspended particulate matter (SPM) and sediments were measured along the salinity gradient in the Cay River–Nha Trang Bay estuarine system in dry season. Most trace element contents were at natural levels. Particulate metals were characterized by the most significant loss in the frontal zone of the estuary with the highest horizontal gradients within the salinity interval of 0–8–20‰. Sedimentary metals were largely controlled by the accumulation of their most fine-grained host minerals in the sea floor depression. The calculation of the enrichment coefficient (KSPM/Sed) revealed associations of elements with a similar geochemical behaviour. Ti, Ca, Zr, Sb and W (KSPM/Sed ≪ 1) are primarily accumulated in estuarine sediments. Co, Cu, Ni, and Mo (KSPM/Sed ≫ 1) are removed out of the estuarine zone with surface water layer SPM. Al, Fe, Mn, Li, V, Zn, Sr, Sn, Cs, Bi, Pb and U (KSPM/Sed ≅ 1) are most likely controlled by their clay host minerals abundant in both sediments and SPM.

The Metallic Trace Elements (MTEs) occur in the waters and sediments of wadis with low concentrations. Their mobility is controlled by several physico-chemical parameters (Eh, pH and dissolved oxygen). To determine the effect of these factors on the concentration and mobility of metallic trace elements (Cd, Cr, Cu, Fe, Pb and Zn), bimonthly monitoring of physico-chemical parameters was conducted during the period from November 2013 to January 2015. The results obtained show that the MTEs are very influenced by the variations of the pH and Eh. Under natural conditions, neutral to basic pH and oxidizing medium, only lead is present in waters with high values, indicating its solubility in water and its release of sediments. Other MTEs have high concentrations in sediments, indicating their adsorption and/or chemical precipitation trapping qualities. The spatial monitoring of these MTEs shows the effect of the confluence of the wadi with its tributaries on the variation of its concentrations.

The indispensable water supply of major reservoirs in Pakistan, essentially depends on meltwater runoff, mainly generating from the Upper Indus Basin (UIB). The present study includes snowmelt runoff simulation within Gilgit River, basin a sub basin of UIB. Snowmelt runoff model (SRM) incorporated with MODIS remote sensing snow cover products, was selected to simulate the daily discharges and to calculate the contribution of snowmelt impact on the discharge within Gilgit River basin, during the early 21st century (first decade). Our results revealed a Nash–Sutcliffe efficiency (NSE) as R2 (0.81) and average volume difference as DV (−0.51) in observed and simulated flow. Almost 9.2% of the total basin area is covered by glacier and permanent ice cover which contributes to the river runoff during summer. We also noted that the observed efficiency of the model becomes uncertain during high flow months such as June, July and August, such ambiguity during summer was attributed to glacier-melt runoff, which generates in August by the melting of glaciers.

Malaria is one of the infectious diseases with the highest number of cases worldwide. It has always been linked to aquatic environments, since these can be a necessary reservoir for the anophelines that transmit the disease. This study analyses the role that unhealthy water bodies have played, since the early 20th century, in the most endemic and/or prevalent foci of malaria in Spain. Western Andalusia was the region with the largest surface of unhealthy water bodies and wetlands. The desiccation of much of the continental waters contributed to its eradication.

The use of wastewater in agriculture is a good way for countries where water resources are facing quantity and quality problems. The goal is to study the effect of treated wastewater irrigation on the physico-chemical characteristics and soil geochemistry amended and unamended on one hand, and to follow the bioaccumulation of heavy metals in soils and sunflowers on the other hand. Wastewater and by-products of Sfax wastewater treatment plants and Agareb wastewater treatment plants are widely used for irrigation. The geochemical analysis of these waters shows enrichment in nutrients (nitrogen and phosphorus) and reveals high levels of exchangeable bases. Compost and sewage sludge brought organic matter and nutrients to the substrates, these elements are essential for the growth and the conservation of plant life. Maximum sunflower development was found in the presence of sewage sludge and following irrigation with Agareb treated wastewater (82 cm in length and 479 μg\gMF soluble sugar in plant tissues). The experimental results also show that the addition of sludge, with small quantities of metals from treated wastewater, to the substrate resulted in a decrease of the exchangeable amounts of these metals. This reduction is probably due to their strong immobilization.

The objective is to study the impact of treated wastewater on the physico-chemical parameters of soil and amended soil with compost or sewage sludge, their effects on plant development as well as the accumulation of heavy metals in cultivated plants. The study was conducted using the wastewaters of the Sfax North treatment plant and the Agareb treatment plant. Experiments were undertaken to evaluate the phytotoxicity of metals present in treated wastewater: the implementation is carried out in a greenhouse under controlled conditions, with a regular monitoring of plant morphology, physiology and followed by physico-chemical soil parameters. Sewage sludge and compost resulted in the addition of micronutrients and organic matter in the soil parameters which are considered important for the development and maintenance of a vegetative cove. Following these experiments, optimum tomato plants growth is observed in substrates amended with sewage sludge and irrigated by the Agareb treated wastewater (122 cm). The most interesting observation is the importance of the contribution of sewage sludge that minimizes the phytotoxicity of the effluent.

Phenol formaldehyde resin is a thermosetting plastic which has been used for various applications. The important factor of its versatile use is its thermal stability, resistance to chemical attack and water resistance—which protect it from micro-organism attacks. The hydrophobic nature of phenol formaldehyde makes Kraft paper waterproof upon drying. This property decreases the cooling efficiency of cooling pads. Therefore, it is required to make phenol formaldehyde resin unaffected by the hydrophilic nature of paper. In the present work, phenol formaldehyde is being used to impregnate Kraft paper to make evaporative cooling pads. For this purpose, phenolic resin was synthesized with inorganic additives, at specific ratios and degree of polymerization, which allowed the paper to absorb water when it was impregnated with diluted resin. During the drying process, by evaporation of some volatile elements in phenolic resin, pores are created in the paper which allows it to absorb water. Solid contents of the synthesized samples were also determined. The coating on paper was examined after different time intervals to observe the solubility of the coated resin in water, which ensures the long-term protection of pads from microorganism attacks.

Esposende–Vila do Conde, a nitrate-vulnerable zone, in the littoral north of Portugal, is contaminated by nitrates of an agricultural origin. Measures have been implemented to reduce that contamination. The effectiveness of the measures was evaluated, predicting the time required for the groundwater body reach the quality standard, i.e., less than 50 mg/L for dissolved nitrates. Two methodologies were used, groundwater flow and nitrates transport modelling, and predictive analysis of time series. The transient simulation of nitrate transport shows that the minimization measures imposed in the NVZ are being effective. However, the persistence of concentrations above 50 mg/L in some areas is notorious even in the next 24 years. The forecasting points out to a recovery period of ten years if current agricultural practices are maintained. The prediction of NO3 concentration based on forecasting methodology may not be applicable in the long run because it is a punctual analysis, not taking into consideration the contaminant dispersion dependent on the aquifer characteristics.

The Angads plain aquifer system, composed of a phreatic groundwater and a deep confined aquifer, currently shows that some sites are contaminated with nitrates. These sites are located downstream of the epuration plant of Oujda. The current contamination affects almost 70% of the water collected in the study area, south of the groundwater aquifer. This situation may worsen if a policy of irrigating a large area by the treated wastewater is adopted.

Oued Djemaa is the largest tributary that feeds El Harrach wadi. It comes from Atlas Blidéen (the Tablat Mountains); its catchment area covers an area of 225 km2. The waters of this wadi show a strong alkalinity and a strong mineralization. The upstream waters are well oxygenated compared to the downstream waters. High values of nutrient salts were observed mainly at stations located near agricultural lands. Chlorides exceed 600 mg/l at downstream. The water situation of Wadi Djemaa is poor in the downstream part, the biological oxygen demand (BOD5) reaches a maximum of 255 mg/l and the chemical oxygen demand (COD) exceeds 350 mg/l level of the S4 (Larbaâ city).

The impact of individual septic tank effluent on groundwater quality was investigated in the rural area of the Ain Soltane municipality. The septic tank is a solution for the pre-treatment of sewage. It ensures the partial liquefaction of concentrated pollutants in wastewater and the retention of solids and floating waste. The alluvial gravel aquifer of the Cheliff Plain is especially susceptible to microbial contamination due to the significant number of septic tanks and the high quantity of pre-treated wastewater passing toward the groundwater which may transport bacteria and contaminants over large distances. Geological investigations established the presence of limestone carapace, and stones with high thickness and good permeability, which forms an unconfined aquifer in the area. Groundwater quality monitoring showed a significant degree of an organic pollution in the majority of wells, with very high concentrations of sulfate and chloride exceeding 450 and 250 mg/L, respectively. It also showed the presence of bacterial germs in the groundwater whose origin are fecal, so these monitoring wells are contaminated and are unfit for drinking in this area. The presence of these pathogen germs poses a major problem for public health. This study has identified the effects of septic tank effluent on groundwater quality in Ain Soltane area.

The main goal of the present study is to evaluate the groundwater quality in Gash River Basin, Eastern Sudan. Groundwater is the main source in the area for all purposes: drinking, industrial as well as agricultural. Twenty-seven groundwater samples from agricultural farms in and around Kassala town were analyzed for their major ion concentrations. The TDS content of the collected samples ranged from 245.9 to 869.20 mg/l, whereas the EC values were below the maximum permissible limit of 1400 µS/cm prescribed by WHO for drinking water. The cation and anion concentrations were in the following order: Ca2+ > Na+ > Mg+2 > K+ and $${{{\text{HCO}}_{3}}^{ - }} > {\text{Cl}}^{ - } > {{{\text{SO}}_{4}}^{2 - }} >{{{\text{NO}}_{3}}^{ - }}$$ HCO 3 - > Cl - > SO 4 2 - > NO 3 - . The main groundwater types identified are Ca–(Mg)–HCO3 and Na–HCO3 types. The samples fall in the water–rock interaction zone on the Gibb’s plot. Carbonates dissolution, silicates weathering and ion exchange are the major chemical processes controlling the groundwater chemistry in the study area. The groundwater in the area is suitable for irrigation in terms of sodium adsorption ratio SAR and residual sodium carbonate RSC, both of which are below the permissible limit, 10 and 1.25, respectively.

This paper examines the trace elements level in the shallow groundwater of the Guenniche plain (North Tunisia) and its suitability for drinking water use in comparison with national (NT 2013) and international (WHO 2006) standards. Samples collected from twenty (20) wells and ten (10) streams in May 2016 were analyzed for the most common trace elements contents (arsenic, cadmium, chromium, copper, iron, manganese, mercury, selenium and zinc). Cadmium (1.14–6.11 µg/l) and mercury (0.06–2.89 µg/l) showed higher values in surface water in comparison to the groundwater (0.06–5.43 µg/l for Cd and 0.04–1.91 for Hg µg/l). The severely polluted wells, located in the El Alia region in the border of Wadi El Malah, are considered to impose high human health risk. The irrational use of pesticides, the uncontrolled waste disposal and the untreated industrial wastewater effluents directly into the streams are strongly associated with the deterioration of the water quality of surface and groundwater of Guenniche plain.

Fire sources in indoor spaces keep increasing, especially because of the growing number of electrical and electronic equipment uses. To reduce the risks of fire, several chemicals, called flame retardants (FRs), are used particularly in brominated compounds (BFRs). Polybrominated biphenylethers (PBDEs) are widely used in industry to prevent fires. These compounds are part of the composition in many consumer products (textiles, electronics, plastics…) in order to reduce their flammability. They have a pronounced structural similarity with thyroid hormones and they are strongly suspected for being responsible of endocrine disruption processes. The pathways of PBDEs to surface waters are multiple: atmospheric inputs, releases of Waste Water Treatment Plant (WWTP), urban storm-water discharge (USD), leaching or erosion of contaminated soils (atmospheric route or following urban sludge amendments). To identify the relative importance of each source of inputs in PBDE at the level of a peri-urban elemental catchment area, a flow assessment was carried out at the level of the basin of the Charmoise, France.

Geochemical modeling and environmental isotopes were used to determine the hydrogeochemical evolution and the main factors controlling the groundwater chemistry in Misaan, South of Iraq. All available δ18O and δ2H data for the study area are plotted along the Global Meteoric Water Line (G-MWL) and Mediterranean Meteoric Water Line (M-MWL), indicating a meteoric origin of all waters. The groundwater samples were exposed to evaporation before entering the aquifer. Tritium values of groundwater are between 0.8 and 1.2 TU. These are estimated as modern and pre-modern (older than about 50 years). The geochemical modeling results show that the dissolution of dolomite, gypsum, halite, siderite, the cation exchange of Ca2+/Na+, and the precipitation of calcite, sylvite and hematite are the main chemical reactions in the first period (dry period), whereas there are no specific reactions that can be shown in the second period (wet period). The inverse geochemical modeling shows that the main reaction controlling the groundwater quality is the Dedolomitization process (dolomite dissolution driven by anhydrite dissolution and calcite precipitation).

The characteristics of the groundwater system in Iresa-Apa, Oyo state, Nigeria, were studied using the Piper linear approach. Twenty-four water samples were randomly collected to cover the area of study. The analyzed cations from the samples are Mg2+, Na+, K+, and Ca2+, while the anions are CO32−, HCO3−, SO42−, and Cl−. The three hydrochemical facies identified are Ca–Mg–Na, Ca–Mg–Na–SO4, and Na–K–Cl–SO4 types. The similarities in the observed water types suggest that almost the same geochemical processes are controlling the cation-anion reaction of the groundwater system in the study area.

Annaba Bay is the ultimate receiver of innumerable chemical substances issued from various anthropogenic activities. These telluric releases could have biocidal properties. In order to preserve the quality of the coastal waters and to limit these flows that are dangerous for the marine environment, seasonal monitoring of water quality of the two main wadis has been carried out. The results show that Bouhamra wadi is mainly polluted by organochlorine and organophosphate insecticides, herbicides and fungicides. While the Seybouse wadi is affected mainly by organophosphate insecticides, herbicides and fungicides. The quality of the wadis is very poor with respect to organochlorine, organophosphate insecticides and herbicides. Acceptable quality is attributed to water with respect to fungicides.

The present research was performed in the Ferrara Province (Italy), an intensively cropped low-lying landscape covering 2636 km2, situated in the southern portion of the Po River valley. The foremost used fertilizer in this zone is synthetic urea which is known to induce nitrate leaching towards the unconfined aquifer. Approximately 800 soil samples, distributed throughout the most representative soil types of the area, were collected from the ploughed layer (0–50 cm below ground) and subsoils (50–100 cm below ground) in 2010. Soil samples were analyzed for: soil porosity, dry bulk density, soil water content, ammonium, nitrate and nitrite. A subset was also analyzed for: urea, soil pH, total organic carbon, and total and organic nitrogen. Scatter diagrams showed an accumulation of ammonium in peaty subsoils, whereas in drained sandy soils ammonium was, in general, very low. The most acidic peaty subsoils were characterized by high ammonium concentrations (20–70 mM-N/kg of dry soil), while the peaty soils amended with poultry chicken manure showed the lowest ammonium concentrations. Instead, the largest accumulation of NO3− was observed in sandy and loamy subsoils (10–27 mM-N/kg of dry soil), where the deep water table and neutral-alkaline soils pH delivered the best conditions for nitrification.

This paper presents the results of assessing the hydrogeological windows’ impact on the Podol’sko-Myachkovskii aquifer contamination in Moscow as the most important reserve source of drinking water supply. Groundwater contamination in these territories can occur due to rapid mixing of contaminated groundwater of the overlying above-Jurassic aquifer and pure groundwater of the Podolsko-Myachkovskii aquifer. The study consisted in the analysis of the water chemistry data of these aquifers; the choice of the elements—indicators of groundwater contamination; the analysis of the indicators’ distribution schemes and comparison with the boundaries of hydrogeological windows. The research results testified to the significantly elevated concentrations of contamination indicators in the Podolsko-Myachkovskii aquifer at the sites of hydrogeological windows allocated within the specific geostructural and hydrogeological conditions.

El Harrach wadi is one of the largest wadis that cross the plain of Mitidja. The current state of the wadi is calamitous, and its influence on the Algerian coast is disastrous since it became an open sewer; this wadi poisons the lives of local residents and has become a real problem for the whole commune of El Harrach and one of the factors degrading the water quality of the Bay of Algiers. In altitude, the pressures on the Oued El Harrach come mainly from the agricultural activity. At low altitude, these pressures are the result of human activity; they may be the result of population growth, the rapid expansion of urban areas, the development of agricultural activities and industrialization. Water quality is poor in all downstream stations. In summer, in the H9 station (Baba Ali town) where the degree of pollution is very high, the BOD5 exceeded the limit, reaching a maximum of 238 mg/l. The results of the COD also indicate that the water quality is bad. The COD reaches a maximum of 407 mg/l, in summer at the H11 station (City of Baba Ali).

The construction of Hammam Grouz dam allowed to store the quantities of runoff water inside the Haut Rhumel watershed extended over 1130 km2. The dam is destined to supply drinking water. The territory of the watershed has witnessed an expansion of the human activity—with its ensuing socioeconomic accessories—which was followed by an irrational dumping of various toxic substances which have been accumulating downstream. The dam’s waters are contaminated by organic pollutants due to domestic, agricultural and industrial discharges stemming from anthropogenic activities within the watershed. These organic pollutants will be leached by the rainwater and transported by the streams to the dam. The objective of this work is to study the evolution of some organic parameters analyzed during the years 2016 and 2017, based on the standards recommended by the WHO, and to identify the degree of contamination of dam waters using the methods of the OPI and IHE for December and July of 2015, 2016 and 2017. The results obtained show high concentrations of the analyzed parameters, with an increase recorded during 2017, indicating high organic water pollution. The degree of pollution, according to OPI and IHE, is moderate to high for the dam waters.

The purpose of this work is to evaluate the impacts of strawberry crop irrigation with treated wastewater (TWW) as compared to fresh water (FW) irrigation on crops productivity. Different dilutions of TWW from urban and mixed urban-industrial origins were used for the irrigation of strawberry in pots. This crop was selected as a fruit model species for its high economic value in the countries involved in the project, and due to the high water-content of this fruit, it is presumably vulnerable to the presence of residual organic micropollutants dissolved in reused TWW. Chemical contamination indicators—polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), ethoxylatedalkylphenols (APnEOs) and alkylphenols (APs)—were studied.

According to the United Nations World Water Development Report 2017, wastewater, which is an untapped resource, effluents from domestic discharges into Algeria are discharging: A volume of collected sewage of 1570 × 106 m3/year. Only 275 × 106 m3/year of wastewater are treated (17%) Of the 17% purified, only 7% are used in irrigation (19.3 × 106 m3/year). This work, conducted in the 18 sewage treatment plants of the Wilaya of Mascara, provides quantitative and qualitative results, which can be exploited by decision-makers in the water resources sector.

The thermal and mineral waters, with high mineral contents from the geothermal fields of Alaşehir, Turkey, and which are discharged onto the ground surface, can cause contamination in surface water, in ground water, and in soil. Because of the fact that the water resources of the region are used for drinking and irrigational purposes, the evaluation of water quality is perfected in this study. Additionally, the surface soil samples are analyzed for their boron, arsenic and other contaminating substances to depict the measurement of the contamination. The results acquired from the analysis of the water samples suggest that some of the components (particularly B, and As) in some of the samples exceed the drinking-water limits. Also, some of the soil samples collected near the geothermal fields are contaminated with B, As, S, Hg, and other contaminants sourced from geothermal fluids, in a moderate to extreme degree. Further, contaminants in soil and water are expected to enlarge in the future unless effective sewage collection and treatment are present in the geothermal fields. This paper discusses the geochemical evaluations of the availability of B, As, and other contaminants derived from the geothermal activities within soil and water in Alaşehir and its environs. Proper re-injection of the thermal and mineral waters into the geothermal reservoirs is the best way to dispose of the geothermal fluids and cope with contamination problems.

In Santiago Island, the overexploitation of coastal aquifers and pollution are among the main problems related to groundwater resources assessment and management. The national water authorities are dealing with brackish groundwater for agriculture and human supply in numerous parts of the Island, as it is the only type of water available. Solutes and environmental isotope obtained in different aquifer systems were used in the identification/sources of groundwater resources degradation. Chemical and isotope analyses were carried out in groundwater samples in order to understand the role of anthropogenic activities and the main origin of salts in the groundwater units. The results obtained indicate water-rock interaction mechanisms as the major process responsible for the groundwater quality (mainly Ca–HCO3-type), reflecting the lithological composition of the Island’s geological formations. The geochemistry, together with the isotopic data, gives essential information on groundwater recharge, as well as on the identification of salinization mechanisms (e.g., seawater intrusion, salt dissolution, and marine aerosols). The isotopic pattern presented by part of the groundwater samples can be related to direct infiltration of irrigation waters undergoing significant evaporation, during the dry periods. Carbon-14 determinations (six boreholes) indicate an apparent groundwater ages between 1.3 and 3.1 ka BP.

In order to better understand the hydrogeological functioning of the Menzel Bourguiba aquifer system (NE Tunisia), chemical and isotopic (18O, 2H) analyses of water are carried out. This work highlights the fact that the water of this aquifer system is highly modified by geochemical interactions: cationic exchange and precipitation/dissolution phenomena. By using isotopic tools, it was shown that the water of this aquifer system has been recently recharged by direct infiltration from the boundary and in the valley of wadis.

The shallow aquifers in the Mediterranean coastal areas are potential groundwater resources for many purposes. Groundwater from sands and sandstone deposits in the Medjerda lower valley aquifer (Northeastern Tunisia) represents a source which is characterized by high saline variations with Total Dissolved Solids (TDS) levels up to (19,000 mg/l) and with high Cl− (>4000 mg/l) and Na+ (>3000 mg/l) contents near the coastline, indicating the saline nature of the groundwater. This study consisting in an integrated geophysical approach (using Vertical Electrical Sounding (VES)) and hydrochemical analyses (60 groundwater samples) to circumscribe seawater intrusion phenomena. Several VES results were utilized using Schlumberger configurations with AB/2 « ρa = ʄ (AB/2) » varying from 1 to 200 m. The low resistivity (<5 Ω m), as saline water intruded up, extended over several km inland within the eastern parts of the study area. Mapping of TDS, Cl−, Na+ and iso-resistivity using GIS tools and electrical pseudo-sections revealed the extent of the seawater intrusion inland and the presence of direct cation exchange linked to seawater intrusion and dissolution processes associated with cation exchange. Finally, we demonstrate that these results may be used to enhance the management of the groundwater resources in the Medjerda lower valley aquifer in a complex terrain.

Saltwater intrusion through the coastal rivers is threating the groundwater aquifers of the southwest coast of Bangladesh. This paper comprises the simulation and assessment of groundwater movement and salinity transportation in the southwest coastal aquifer of Bangladesh. A groundwater model was developed, through the porous medium of the aquifer for a range of existing and possible future conditions. This groundwater model was developed by comprising the model setup and flow properties, and by assigning boundary conditions. The development model was accomplished using GIS, Surfer 13 and Visual MODFLOW Flex. After developing the numerical model for a time period of 10 years, the concentration of salinity in groundwater was found to have increased at a very slow rate due to the intrusion of saline water from the river water.

Fifty-five groundwater samples were collected during each monsoon season representing the pre-monsoon and post monsoon seasons for four consecutive years from 2014 to 2018 to assess the groundwater quality. As the study area represents a coastal aquifer, seawater intrusion studies were also carried out in the northern region of Chennai Metropolitan City, Tamil Nadu, India. They were analyzed to establish the physical and chemical characteristics, such as pH, EC, TDS, Ca+, Mg+, Na+, K+, Cl−, HCO3−, SO4 and NO3. Chennai Metro city experienced more than 40 cm of rainfall within two days due to a cloudburst during December 2015 and its effect is being reported.

Hypersaline (HS) coastal groundwaters along the Kuwaiti shoreline were identified by collecting samples along the Kuwait Bay and along the open sea coast. Out of the 28 collected samples, 9 samples were considered as hypersaline considering the salinity of the Kuwaiti sea water. They were mostly of Na–Cl facies and the ratios of the different elements to Cl were studied to determine their source and nature. Few HS samples were acidic, and it was observed that these samples have representation of sulfides. The PHREEQC model reveals that the pO2 values in the acidic samples were lesser. The mole values of CaSO4 and the saturation states of Anhydrite and Gypsum were higher in these samples. The model was also attempted for temperature variations and it showed variations in pH, Ionic Strength and Saturation states. The statistical analysis of these HS waters reveals that the impact of desalination rejects, waste water and urban sewage, variation in water level of the aquifers and occurrence of H2S gas governs the hypersaline nature of the groundwaters along the coast.

The geophysical, hydrogeochemical and climatological investigations of the plio-quaternary aquifer, in Garaat Douza (Moulares-Redayef Mining Basin, Southwestern Tunisia), enabled us to identify the origin and the extension of salinization in time and space. Thus, the hydrogeological study has revealed a piezometric drawdown, showing the insufficiency of the natural recharge of the aquifer due to the low rainfall events and the increasing use of groundwater. The hydrochemical study has shown that the high salinities are recorded at the level of Garaat Douza (outlet of the aquifer). The geophysical study (ERT and VES) has revealed that the surveyed area is characterized by the presence of two zones with different resistivities. The first zone is near the outlet, and generally has very low resistivity values (less than 3 Ω m) revealing the presence of salt-water, whereas in the second zone (far from the outlet), the resistivity values are higher than 100 Ω m, testifying for the presence of water with a better quality than the previous one.

The determination of the relationship between hydrochemical variation and seawater intrusion within the coastal alluvial aquifer of the Essaouira basin (Morocco) was the main objective of this investigation. In order to achieve this objective, the Hydrochemical Facies Evolution Diagram (HFE-D) was used. The obtained results show that the hydrochemical variations of groundwater from the coastal alluvial aquifer of Essaouira basin can be interpreted in terms of intrusion of seawater and bases exchange phenomenon. However, the exploitation of the HFE-D diagram results can lead to a better management of the aquifer by identifying areas affected by the marine intrusion.

This study presents the first results from the multicriteria approach using geochemical and isotopic tools to understand the origin, geochemical evolution and renewability of deep groundwater in Wadi Guenniche basin, northeastern Tunisia. The study area is a coastal plain that plays an important regional socio-economic role, as the groundwater resources are the most important source for agricultural and drinking supply. Geochemical and isotopic (18O, 2H) data show that the water-rock interaction and cation-exchange process are the major geochemical mechanisms controlling hydrochemical evolution of groundwater. Isotope data (Oxygene-18, deuterium and tritium) point out recent recharge by atmospheric precipitations. Samples from deeper boreholes (300 m) characterized by low 18O and 3H contents suggest older recharge under different climatic conditions.

Geochemical and both stable (δ2H, δ18O and δ37Cl) and radioactive (3H) isotopic determinations were applied to identify the main processes involved in the increased salinization of groundwater in the Mio-Pliocene aquifer of Oued Laya, located in the eastern coast of Sousse, Tunisia. Geochemical results indicate water-rock interaction, including dissolution of evaporitic minerals, as the major process responsible for groundwater salinity. In addition, seawater intrusion is also responsible for the groundwater mineralization in this region, resulting in Cl-Na-type groundwaters and degradation of groundwater quality. The geochemical and isotopic composition of the groundwater reflects the lithological composition of the subsurface geology, the presence of salt basins (“sebkhas”), and ion exchange processes between the groundwater and clays.

The study aims to evaluate groundwater geochemistry characterization of multilayer aquifers of the Sedimentary Rock in Mekelle Outlier in order to gain knowledge on the dominant geochemical processes and water quality status. Groundwater samples were collected and analyzed for major ion chemistry and stable isotopes (δ2H and δ18O). The findings reveal that the sources of ions into the groundwater are controlled by the duration of the water-rock interaction in confined and semi-confined aquifers. The chemical facies of the water evolve from Ca–HCO3 to Ca–SO4 along the flow direction. The stable isotope of δ2H versus δ18O signifies a source of local meteoric water. The isotopic signature of few samples depicts the effect of the evaporation process prior to infiltration.

The CO2-rich mineral waters from Vilarelho da Raia, Chaves, Vidago and Pedras Salgadas region (N-Portugal) were analyzed for 37Cl/35Cl, Cl and other major elements. Local rain and shallow cold dilute waters were also studied. The main objective of this study was to use Cl geochemical signatures together with Cl isotope geochemistry to improve our knowledge on the origin of Cl in the hot (≈76 °C) and cold (≈16 °C) Na-HCO3-CO2-rich mineral waters that discharge in the region. Chlorine, a good tracer of water-rock interaction, presents a strong correlation with sodium (dominant cation) indicating that Cl− present in the mineral waters originates from water-granitic rock interaction. δ37Cl isotope signatures indicate that i) 37Cl/35Cl in the studied mineral waters can also be explained by water-granitic rock interaction and ii) the contribution of a deep-seated (upper-mantle) Cl component should not be excluded.

In this study, groundwater level and fluoride data of fifteen years (from 2003 to 2017) have been used to identify the influence of water level and its fluctuation on the variation of fluoride (F−) concentration in groundwater. For this purpose, five locations have been chosen along the groundwater flow direction and amongst these locations, two locations are situated at or near the recharge area, having F− concentration below 1.5 mg/l (most of the time), two other locations are situated around the discharge area, having F− concentration above 1.5 mg/l (most of the time). At the transitional location between recharge and discharge, F− concentration went above or below 1.5 mg/l in a proportional way. The time series plot of the water level and F− concentration at each location show that the addition of freshwater during monsoon generally dilutes F concentration in groundwater. The positive relation between water level fluctuation and fluctuation in F− concentration also reflects that fluoride release in groundwater is mostly due to water-rock interaction. The average fluctuation in F− concentration increases along the flow line, which reflects more water-rock interaction in the discharge area than in the recharge area. The points in the discharge area showed the highest water level fluctuation, fluctuation in F− concentration and the highest hydraulic conductivity.

Both people and the environment are continuously exposed to sources of radioactivity. Continuous monitoring of the concentration of natural and anthropogenic radioisotopes is of the utmost importance in the estimation of an individual’s received dose. In order to evaluate the radiological safety of locally sourced desalinated water and seafood, the activity concentrations of Cesium-137 (137Cs), Uranium-234 (234U), and Uranium-238 (238U) in Kuwait Bay seawater were measured. Ten 25-L seawater samples were collected from Kuwait Bay and underwent radiochemical analysis. 137Cs levels in the samples were determined by the Ammonium Molybdenum Phosphate (AMP) co-precipitation method, followed by gamma spectrometry measurement. 234U and 238U levels were determined by a radiochemical separation using anion exchange chromatography, followed by an alpha spectrometry measurement. The levels of 137Cs, 234U, and 238U in Kuwait Bay are considered low and comparable to other regional marine water levels. These low levels do not pose a radiological hazard of locally sourced desalinated water and seafood consumption. The ratio of 234U/238U was also calculated in order to investigate the the impact of any anthropogenic sources. These data can be considered a baseline reference for any future comparative analysis, especially since some Gulf countries are initiating their first nuclear reactors within the next few years.

In an attempt to establish the geologic structures in connection with the assessment of groundwater resources within Igbeti crystalline basement complex terrain, Landsat 8 and aeromagnetic data were analysed using various sub-menus of Geographic Information System (GIS) and 2D Fast Fourier transform filters, respectively. Visual and automated models of the landform types and relief, the range of color composition of the Landsat 8 data controlled by the climato-morphogenic processes and alternating positive and negative magnetic anomalies revealed the contrasting lithologic units in the basement rock of the area. Lithologic contacts were developed with a vertical gradient while the linear features decipher the fracture orientation in concordance with a northeast-southwest low gradient trend. The associated groundwater flow direction revealed catchment in the northern, northwestern and southern parts of the area and indicated low run off, more infiltration time and better recharge potential for these regions, while zones of high degree indicated otherwise. The hydrology potential for groundwater development in the area should be targeted at geologic deformation.

Remote Sensing (RS) data have been widely used in combination with Geographic Information System (GIS) in groundwater resource management. Thus, (GIS) and (RS) integration tools with Geophysical resistivity are proposed to define the groundwater potential zone in the study area. Remotely sensed data of the Landsat 7 ETM+ have been used in this study. Different digital image processing techniques were applied to the satellite images to reveal the geological and hydrological aspects. The Geophysical method used in this study is electrical resistivity Vertical Electrical Sounding (VES), in this case, Schlumberger electrode array was applied. Thirty-four VESs have been conducted in the study area. The interpretation of studied data showed that the area consists of three main aquifer types: Sandstone aquifer (the best one), alluvial deposits (of minor importance) and weathered basement complex aquifer (of lesser concern).

Sand sheets and barchan dunes are a dominant landscape feature of the hyper-arid deserts of North Africa and the Arabian Peninsula. The ability to characterize their morphology, moisture content, internal layering and structure provides unique insights into both the local and regional paleoclimatic conditions that prevailed during their formation and development. We constrain the moisture content inside barchan dunes and its association to the dune geomorphology, internal structure and evolution by performing a radar attenuation study at the frequency band from 40 to 150 MHz carried on six barchan dunes in Qatar. Our results suggest that the measured average loss across the dune is ~10% higher than the expected attenuation for dry sand. The inner parts of the dune show higher losses than its outer parts. When compared to laboratory dielectric losses of desiccated sand, our observations suggest that despite the harsh and arid conditions, these aeolian landforms are capable of maintaining a significant amount of moisture arising from the sparse precipitations, several meters deep under their surface. We examine how such moisture content impacts the dunes’ dynamics and implications for understanding precipitation variability through the Holocene.

Electrical resistivity imaging (ERI) is widely used for near-surface characterization in geophysical applications for hydrogeological, environmental and engineering investigations. This study involves the application of the two-dimensional (2D) electrical resistivity imaging (ERI) to delineate structures that are suitable for groundwater occurrence in a crystalline basement complex terrain. The dipole-dipole array, which is sensitive to weathered and fractured zones commonly associated with groundwater accumulations in a basement complex, was deployed for the measurements. The survey was conducted to locate possible points for siting productive boreholes in a site at Abeokuta, southwestern Nigeria, as previous boreholes and wells drilled within the study site failed.

Geological field mapping and vertical electrical soundings (VES) were conducted in Igbo-Ora, southwestern Nigeria in order to unravel the subsurface structures, as part of the preliminary investigations for groundwater resources assessment, development and management in a crystalline basement terrain, southwestern Nigeria. The geological survey was carried out to produce a local geological map with spatial distributions of different basement rocks and their structural trends. Metamorphic and igneous rocks make up 90 and 10%, respectively, of the rocks in the study area. They include the banded gneiss, biotite granite gneiss, quartzite/quartz-schist and granitic intrusions of varying grain sizes. Twenty-five VES surveys were conducted within the biotite granite gneiss terrain of the area, using Schlumberger array, providing layering and geoelectrical parameters. Three geoelectric layers delineated from the VES 1D inversion models are clayey sand/sandy clay top soil (overburden), partly weathered or fractured basement and fresh basement. The corresponding inverse model resistivity values ranges are: 209.7–2298.0, 45.1–346.2 and 1013.7–33,124.0 Ωm with bottom depths ranges of 0.9–2.9 and 4.6–42.0 m, respectively. The topmost clayey sand/sandy clay layer will serve as the protective layer, while the saturated portion of the partly weathered or fractured basement, at depth, favors groundwater exploration and development in the study area.

This work is aimed at generating 2D aquifer porosity and hydraulic conductivity using 2D resistivity techniques. Two resistivity profile lines were measured in an island that is characterized by complex geology. Then, rock and soil samples were collected along the resistivity lines, together with water samples for laboratory analysis which includes determination of the electrical properties of the samples using an inductance-capacitance-resistance (LCR) meter to calibrate the results. Subsequently Bussian equation was employed to determine the aquifer porosity, and then, the hydraulic conductivity of the aquifer via the Kozeny-Carman-Bear equation. Next 2D cross-sections of both porosity and hydraulic conductivity were plotted using surfer software. The result was compared with the pumping test and the results were found to be very close to one another (40 and 38 md−1), respectively. These findings would enhance researchers’ understanding of patterns of groundwater flow in an aquifer system.

This study was inspired from the Kedah and Penang water crisis with an objective of solving the problem by applying the conjunctive Riverbank Filtration (RBF) technique. In particular, the RBF technique will improve the water security and sustainability of the water resources. The RBF technique will be exploited in this paper via a case study model, including the evaluations of the effects of groundwater pumping and RBF operation relative to the installation of wells. This study also investigated the impact of pumping rate on flow paths, travel time, the size of the pumping and capture zone delineation, and groundwater mixing within a pumping well. Numerical modeling packages, MODFLOW and MODPATH (particle tracking), were used in these investigations, where the proposed method performed infiltration safely and achieved the ideal pumping rate. The results indicated that the migration of river water into the aquifer is generally slow, which depends on the pumping rate and the distance of the well from the river. The water arrived at the well by the end of the pumping period (1–5 days) at 1054.08, 1238.62, 887.064, 1441.34 m3/day for test wells TW1, TW2, TW3 and TW4, located 5, 10, 15 and 20 m, respectively, from the river. During the 3-day pumping period, 37.5, 23, 21 and 11% of the water pumped from the TW1, TW2, TW3 and TW4 wells was river water, and for pumping periods of 8, 13, 14 and 27 days from TW1, TW2, TW3 and TW4, 100% was river water.

The use of diurnal or seasonal water table fluctuation (WTF) to estimate groundwater evapotranspiration (ETG) is increasing applied in ecohydrological studies. In this study, we applied the WTF method for a shallow aquifer in Senegal over the dry season 2000–2013. To analyze the applicability and validity of the WTF method for this site, the unsaturated/saturated system was first simulated using the 1-D HYDRUS model. The simulated drawdown of the water table over the 14 years ranges from 18.1 to 113.2 cm, and from 10.4 to 101.9 cm for a bare soil and a perennial grass scenario and is highly related to the annual rainfall of the previous rainy season. The results indicate that the estimated actual evapotranspiration (ETa) from the Hydrus model ranged between 0.22 and 1.11, and between 0.23 and 1.27 mm d−1 in bare soil and vegetative condition, respectively. Results indicate that higher ETa values were observed when the water table is shallow, suggesting that ETa is driven mainly by the water table depth.

This research is focused on extracting and evaluating geomorphological features such as slope, elevation, drainage and wetness from remotely sensed data using principal component analysis (PCA). These features are variables and have significantly influenced the geomorphological control on groundwater occurrence. The software ENVI 5.0 was used to extract wetness information by performing a tasselled cap transformation and extraction of slope data, GLOBAL MAPPER 15 was used to extract information on drainage and ARCMAP 10.3 performed the drainage density using the kernel density algorithm (KDA). From the PCA performed, the most suitable principal component was PC3. It was then negated in order to achieve the desired result because it contains the information on the variable that influences the geomorphological control on groundwater. A Multi-fractal analysis (MFA) was performed to identify the threshold or area with high influence of geomorphological factors on groundwater distribution. From the threshold, three classes were identified and thus, areas with low, moderate and high potentials have been delineated corresponding to 199.7834, 501.6503 and 67.0763 km2 respectively. It can thus be concluded that other geological, hydrogeological and hydrological factors may have a stronger control on the occurrence and distribution of groundwater within Keffi and its environs than the geomorphology.

Our work focuses on studying the physico-chemical quality of superficial aquifer of Oued M’Zab in order to identify their potability, and their impact on human and the environment. To achieve this goal, we carried out physicochemical measures on forty-five wells aligned along the Oued M’Zab, (that is measuring pH, EC, Ca++, Mg++, Na+, K+, Cl−, SO4–, HCO3− and NO3−), allowing the classification of this water according to international standards. The findings in the framework of this work show that the water of the aquifer is close to neutrality and is highly saline. The water facies is variable, of anionic dominance, chlorinated, sulphated or balanced; and of cationic dominance, sodium, calcium, magnesium or balanced. According to WHO standards, the majority of these waters are classified as not drinkable. The location of contaminated wells must be reported and prohibited for human consumption.

Khondalitic suite (garneti ferrous Sillimanite gneiss) of rocks occurs extensively in the Eastern Ghats of India. When the khondalite is highly weathered due to the presence of water at low lying areas such as water courses, it becomes kaolinised and acts as a barrier to the lateral movement of groundwater, causing it to be accumulated on either side of the stream, turning the areas adjoining stream courses into non-potential groundwater areas. From electrical resistivity investigations, it has been found that the kaolinised layer is progressively increasing towards the stream, making little to no aquifer thickness near the streams. The resistivity of the kaolinised layer is found to be less than 25 Ω m and that of the weathered and fractured khondalitic aquifer is between 25 and 65 Ω m. Hydrogeomorphological studies have indicated that mostly stream courses are lineaments and between the two lineaments, there is a shallow weathered pediplain where more of high-yielding (>8000 lph) wells are observed. The transmissivity and storage coefficient values of the aquifer has decreased progressively towards the stream conforming the earlier investigations. The hydraulic conductivity of the kaolinised layer varies from 1.6 to 1.9 m/day while that of the fractured layer below varies from 1.6 to 2.3 m/day.

Water supply entails many activities, among which is to ensure a water supply with a quality that meets the WHO potable water standards. Water resources protection will secure good water quality and quantity in arid and semi-arid regions. Any human activities on the recharge area of a given water resource increase the contamination hazard and vulnerability of the wells and springs that are fed from this resource. This issue becomes problematic in semi-arid and arid zones, where the water resources are quite limited and the effect of dilution of effluents by the rainfall or in the aquifer storage is minimal and rare. Today, the wastewater effluents of the main cities are also discharged into these wadis, which contaminates the environment and the groundwater. The urban sector is growing fast and it produces effluents that are transferred to the wadis flowing into the Jordan Valley. This study focuses on Marsaba-Feshcha (M-F) Basin as one of the most important basins in the Jordan Valley that is connected to the Dead Sea. Rough estimations were provided for the spring annual discharge of water ranging between 30 and 50 MCM/Y. Vulnerability and risk maps were constructed using ArcGIS and My-Observatory software-based PI map. The hazard map shows the localization of potential contamination sources resulting from human activities and evaluates those according to their dangerousness. The risk map for the M-F Basin was thus created by overlaying the hazard and vulnerability maps.

The excessive use of fertilizers in agriculture led to the increase of the nitrates pollution of wadi Nil groundwater (Jijel, North-East Algeria). The use of fertilizers in high quantities with respect to the plants’ needs will lead to the leaching and infiltration of the excess fertilizers towards groundwater by increasing the nitrate percentage, which ultimately leads the contaminant’s level to exceed the allowed norms of water consumption (50 mg/l). The aims of this work were to assess the aquifer’s vulnerability caused by pollution using DRASTIC and GOD methods. The study is based on the obtained measurements during the field surveys conducted during the hydrological year 2010–2011 and supplemented by the compilation of the information collected from various technical services of Jijel city. The comparison of nitrate-concentration distribution map and that of vulnerability levels obtained by each approach, showed that the DRASTIC method was the most appropriate in this case with a percentage of 71.4% versus 47.2% for GOD method. It was found that the studied water was characterized by a medium to high degree of vulnerability, which requires finding solutions to protect and preserve the water of this area.

This study reveals the potential risk to the quality of shallow groundwater aquifers from the application of agro-chemicals in upscaling crop production to ensure food security within the Atankwidi basin of Ghana, using the combination of DRASTIC and Arc GIS methods. The DRASTIC indices ranged from 41 to 117, representing the lowest to highest vulnerable areas. 34.4, 93.3 and 63.9 km2 representing 20, 48.8 and 33.2% of the area had low, moderate and high vulnerabilities with indices ranging between 41–71, 71–88 and 88–117, respectively. The moderate and high vulnerable areas, which constituted approximately 80% of the area, were underlain by clay-loam and sandy-loam soils, respectively, where major farming takes place. The most vulnerable areas were in the highest elevated areas (recharge), with the shallowest depth to water-table and the highest permeability values. Sensitivity analysis using a map removal approach revealed influential parameters in the order of Hydraulic conductivity (C) ˃ Soil type (S) ˃ Depth to water table (D) ˃ Net Recharge (R) ˃ Influence of vadose zone (I) ˃ Topography (T) ˃ Aquifer material (A). The validation of the model using heavy metals measured in shallow aquifers showed the highest values within the most vulnerable areas and the lowest values in the least vulnerable ones.

The Takelsa multilayer aquifer system, located in north-eastern Tunisia, contains important groundwater resources that have mainly been used for agricultural purposes. To ensure a solid base for the sustainable management of this aquifer system, an adequate comprehensive hydrogeologic investigation was undertaken. A sampling campaign of stable isotopes was carried out in 2016 to identify groundwater recharge and related processes. A groundwater flow model was implemented. The model calibration was performed during a steady state, based on the average state of the period 1980–1984, using Modflow. Modelling results have been determined by a least squares fit of observed heads. The groundwater model was coupled with a physically based model (WetSpass model) used to quantify groundwater recharge and discharge of the Takelsa multilayer aquifer.

Groundwater supports the economy of semi-arid parts of India during the non-monsoon season. However, in the era of climate change and increased water demand, the groundwater supply is at risk. In the current study, the variation in the groundwater levels in the semi-arid upper Godavari basin is examined for pre- and post-monsoon seasons using the Mann-Kendall trend test. The trend in the difference between the groundwater levels during these seasons is also analyzed. Breaks in the groundwater level time series in both seasons are identified using the Pettitt test. The study revealed that, the groundwater levels are mostly increasing in the post-monsoon season. However, more than 60% of wells depict the declining trend of groundwater level in the pre-monsoon season. The gap between the groundwater levels measured during the pre- and post-monsoon seasons is widening throughout the upper Godavari basin. Though the breaks in the pre- and post-monsoon groundwater levels coincide with the major drought year, the negative change in the mean value after the break year cannot be attributed only to climatic variation. Hence, the current study highlights the immediate need for water conservation and water demand management, in the upper Godavari basin.

The shallow quaternary aquifer of the Lake Chad Basin is an important source of drinking water supply and irrigation in the city of Kousseri. Electrical Conductivity (EC), Total Dissolved Solids (TDS) and pH were measured in situ in samples from 161 boreholes, while 8 boreholes selected based on EC spatial variation—were used to determine the concentrations of major cations and anions in groundwater. The pH values ranged between 6.94 and 9.97 with an average of 7.74 ± 0.45 which indicates that the groundwater of the study area is acidic to alkaline. TDS, representing the hydrochemical properties of groundwater, ranges from 45 to 144 mg/L with an average of 76.52 ± 20.16 mg/L. These values indicate that the groundwater of the study area is fresh (TDS < 1000 mg/L). EC of groundwater ranges from 94 to 296 µS/cm with an average of 151.32 ± 40.54 µS/cm. The Pollution Index (PI) determined on 8 points varies between 2.96 and 4.67. This index presents a relationship according to a polynomial model with the corresponding EC values. Substantial differences in EC and PI values are observed in the groundwater of boreholes, which may indicate local contamination.

Tunisia is a water-stressed country, which derives most of its surface water from its northern regions. Given Northern Tunisia’s role as a water provider, this study investigated the hydrological impacts of climate change on five catchments located in this region. Three hydrological models are considered: HBV, GR4, and IHACRES. Climate projections were derived from eleven high-resolution EURO-CORDEX regional climate models (forced by general circulation models; GCM-RCMs). A quantile mapping (QM) bias correction method was applied to correct the climate simulations. Historical streamflow simulations (1970–2000), achieved by forcing the hydrological models with GCM-RCM precipitation and temperature, were first assessed in order to select the most realistic GCM-RCMs for future projections. The remaining bias corrected GCM-RCMs were then used to force the hydrological models in order to achieve projections of streamflow. The evaluation of the streamflow projections was conducted over two time periods (i) mid-term: 2040–2070 and (ii) long-term: 2070–2100 to identify the magnitude of the projected change of streamflow under the climate scenarios RCP 4.5 and RCP 8.5. The hydrological projections were analyzed according to several metrics commonly used by water managers.

The objective of this study was to simulate future flows in Essaouira basin (Morocco) by 2050, using the two-variable Rural Engineering model at the monthly time step (GR2M). The quality criteria revealed very interesting values obtained from the model on the Igrounzar and Zelten stations of the Essaouira basin with Nash higher than 70% and R2 higher than 0.70. The results obtained by the GR2M model under Representative Concentration Pathway (RCP) 2.6 and 8.5 scenarios of the fifth phase of the Coupled Model Intercomparison Project (CMIP5) predict that future flows will show an upward trend of 19 and 43%, respectively. However, under the RCP 4.5 scenario, future flows show a downward trend of 38%. Nevertheless, planning for future uses of water resources in the Essaouira basin should take this situation into account.

Groundwater is a key element for people living in the Sub-Saharian region because it is the primary source of water, covering a crucial role in supplying water for multiple purposes. Water scarcity is becoming a limiting factor for economic development in these basins, as it is in many other basins located in developing countries with arid climates, lagging water infrastructure development, and rapidly increasing populations. Groundwater and climate change make a linked system. Climate change has a huge impact on groundwater, considering the fact that it is one of the main drivers which stresses the resilience of people living in these areas and makes groundwater resource highly sensitive to it. The goal of this paper is to give an integrated view of two focus themes, groundwater and climate change, inside two areas: the first is Dar es Salaam Coastal plain, in the eastern part of the United Republic of Tanzania; the second one is the area of Limpopo National Park, in the Mozambican part of the Limpopo River Basin.

Groundwater resources have been extensively explored in Wadi Al-Fara coastal catchment, located at the northwest of Oman, to supply agricultural, industrial and domestic demands. Consequently, groundwater level has declined, which calls for urgent mitigation strategies to sustain the groundwater resources. Reasonable knowledge of natural recharge to a groundwater basin is fundamental for its sustainability and management. Thus, recharge was estimated using different methods including chloride mass balance (CMB), water table fluctuation (WTF) and groundwater modeling methods in Wadi Al-Fara catchment. Based on the CMB method, the recharge is respectively estimated at about 45 and 8 mm/year for the highland and coastal zones. According to the WTF method, the recharge is estimated as 10–22 mm/year and 6–14 mm/year in the plain and coastal zones, respectively. Modeling showed that a long-term regional groundwater recharge is about 31 Mm3/year (26 mm/year) for the whole study area, and the long-term lateral flux from the highland to the coastal zone (12 Mm3/year) is a major contributor to water resources in the coastal plain.

The Infiltration Potential Index (IPI) was used at Castelo Novo (Fundão, Central Portugal) to delineate favourable infiltration zones. The Infiltration Potential Index is a valuable tool to include in integrated water resources management in crystalline fractured rocks. An integrated approach combining hydrogeomorphology and GIS was developed applying multiple layers of information (tectonic lineaments, hydrogeological units, slope, drainage, land use, and precipitation). Different ranks were assigned to thematic layers and different weights were given to classes according to their contribution for groundwater using the Analytical Hierarchical Process (AHP) methodology. Almost 80% of the area is covered by slightly to moderately weathered (W1–2–W3) granite, having slopes of 5–15° and 15–25°, tectonic lineaments densities of 6–12 km/km2 and 12–18 km/km2 and drainage densities of 6–9 km/km2 and >9 km/km2. Scrub and/or herbaceous vegetation associations and bare rocks dominate. A moderate to high Infiltration Potential Index (IPI) is dominant in the area.

The Upper Tigris Basin lays in the part of the upper historic Mesopotamian Basin, where agricultural activities have been carried out since civilization has passed through settled life. Products such as grain and cotton are grown in this region providing resources not only for Turkey, but also for other Middle Eastern countries. In recent years, irrigation agriculture has started to get more value-added products. However, the national dam for irrigation projects has not yet been completed in this basin, and groundwater is mostly for irrigation. For this purpose, the determination of the basin’s groundwater potential is enormously significant for sustainable irrigation. In this study, groundwater potential of the basin was assessed by handling data of opened water wells. The study shows the groundwater potential is high in the southern, southeastern and eastern parts of the Basin. While the groundwater potential in the western and southwestern parts of the Basin is normal, it has been found to be low in the Northern part.

The Harran Plain is located in the region of Upper Mesopotamia where agricultural activities have been carried out for 4000 years. This region has a very fertile soil for agricultural activities. Its agricultural and socioeconomic values have increased since this area was subjected to irrigated agriculture within the scope of Southeastern Anatolian İrrigation Project. Hence, the determination of the hydrogeological properties and alternative groundwater potential of this basin is vital for sustainability. For this study, hydrogeological data belonging to Sanliurfa-Harran plain and general information about natural water resources were used. Using the DEM data of Sanliurfa province, river basins and geomorphological surfaces were formed. Hydrogeological and geomorphological thematic maps were produced. With the help of thematic maps showing the geomorphological structure, the groundwater potential of Harran Basin was revealed. Besides, groundwater layer levels and aquifer layer thicknesses of the basin have been determined.

Biteira district lies in southern Sudan, underlain by deformed basement rocks. The geological setting of this area, with its position in the heavy savannah region, has produced water scarcity in the dry season. Also, the steady population growth and the expansion of agricultural activities, coupled with desertification and climate issues, have further augmented the stress on the resources of water. To overcome such a problem, we proposed the artificial recharging of groundwater at a specific location as a justified solution. Detailed geological, hydrometeorological, hydrological, and drainage pattern studies—along with an analysis of soil grain size and tests of infiltration—have been taken into consideration in this investigation. In addition, a Landsat image covering the area was analysed to obtain data bearing of regional features and structures. The results show that the selected area is suitable for groundwater recharge, the proposed dam is capable of storing water with a capacity of $$ 20.73 \times 10^{6} \;{\text{m}}^{3} $$ 20.73 × 10 6 m 3 , the infiltration average rate is 1.23 m3/day, and groundwater flow estimated towards NW direction (approximately 285°). The proper position of the potential water wells has been determined. The proposed approach proved to be the most rapid and reliable method to investigate the basement-dominant region for artificial groundwater recharge.

A comparative quantitative study on the impact of two of the most important factors threatening fresh water resources (urbanization and climate change) is presented. Using the Soil Conservation Service-Curve Number (SCS-CN) model, the individual impacts of the development of urban areas and the changes in the climatic conditions on several components of the urban hydrological cycle (runoff, initial abstraction with a focus on groundwater recharge from precipitations) are assessed with a daily time step at the scale of Algiers during the period 1987–2016. For the presented case study, it was found that the changes in the climatic conditions impacted all three components of the hydrological cycle with a higher magnitude than the development of the urban area. A strong correlation between groundwater recharge (and runoff) and the climatic conditions is observed. Moreover, it is estimated that potential natural groundwater recharge in constructed areas can be higher than that in non-constructed ones; an aspect that can shift with changes in the climatic conditions (particularly the changes in rainfall intensity and frequency).

Groundwater potential mapping and its sustainable development are an important aspect in the Lower Valley of Medjerda (LVM) river sub-basin due to increased water demand for irrigation and domestic use. The main goal of this study is to investigate the application of the probabilistic-based frequency ratio (FR) model in groundwater potential mapping at LVM river in Tunisia using GIS. This study includes the analysis of the spatial relationships between Transmissivity and various hydrological conditioning factors such as elevation, slope, curvature, river, lineament, geology, soil, rainfall, and land use. Eighteen groundwater-related factors were collected and extracted from topographic data, geological data, satellite imagery, and published maps. About 60 groundwater data of transmissivity were randomly split into a training dataset, 70% was used for training the model and the remaining 30% for validation purposes. Finally, the FR coefficients of the hydrological factors were used to generate the groundwater potential map. It was classified into five zones as very high, high, moderate, low, and very low. This information could be used by water decision makers as a guide for groundwater exploration and assessment in the LVM River.

The purpose of this work is to evaluate the groundwater recharge using multivariate statistical evaluation and AHP (analytic hierarchy process) as an additional method to the hydrogeological research. This technique was utilized to establish a map that represents the groundwater recharge potentiality. The map extraction is founded on the investigation of multi-criteria input data such as lineaments, land use, lithology, drainage, slope, soil, rainfall and geomorphology. Weights were assigned using the AHP method to all these multi-influencing factors according to their influence on groundwater recharge. Sensitivity analyses were calculated to validate AHP weight results. The presented methodology has been applied to Belkhir region in southwestern Tunisia, which has an arid climate. Agriculture is the main activity in the plains and the use of groundwater has been raised for both irrigation and drinking purposes. This technique revealed the very good, good, moderate, and poor groundwater recharge potential zones. Furthermore, the impact of each influencing factor on groundwater ability was calculated. The results provide significant information that can be useful to ameliorate groundwater development. The approach may also help improve plans for sustainable groundwater resources exploitation.

In semiarid areas, water is a crucial and limited resource and its management is a challenge. Hydrological models allow the estimation of water balance under different land cover and climate scenarios which can help improve the management of water resources. In this study, we used the “DISRUM” model (a Distributed Eco Hydrological Model) to estimate the water balance and aquifer recharge according to different scenarios of vegetation cover changes induced by wildfire and restoration during two hydrological years (wet and dry year) and determine the best scenarios that can substitute the current vegetation cover of a small aquifer in the semiarid area of Southeastern Spain. The main results of the preliminary work show that the vegetation cover has a significant impact on aquifer recharge. Furthermore, reducing the vegetation cover or substituting pine by shrub gave positive results for the aquifer recharge.

A hill reservoir research project aims, among other perspectives, to improve the regional agriculture potential through irrigation of small areas. For such a project, the feasibility study for a given area is fundamental before the establishment of any related applied research works. This paper is of a socio-economic relevance for the Timgad region (NE Algeria) as the presented results consist of a contribution of both socio-economic operators and policy makers. In the study area, water resources are closely related to the regional geology and the main objectives of the establishment of the Foum-Toub hill reservoir is to promote the irrigation of its plain, regulate the flow of the Foum-Toub creek and minimize the silting of the Koudiet Lemdaour dam. The selected sites for the construction of this work are characterized by an impermeable bedrock. Loose material, favorable to serve as borrow areas, can be supplied from the surrounding depressions where sandstone can also be used for the dike construction.

Understanding the role of geological structures in controlling groundwater flow in fossil aquifers is central for proper assessment of groundwater dynamics and aquifer connections. In such settings, connections between deep and shallow aquifers could potentially affect groundwater quality and availability as well as karst formation and landscape evolution. Herein, we integrate available hydrological and isotopic datasets with remote sensing data covering two aquifer units in Sinai and Qatar to indicate the occurrence of significant recharge of gaseous-rich groundwater from deep to shallow aquifers under upward hydraulic gradients along vertical/subvertical faults. Evidence include: (1) the presence of localized recharge mounds ranging from 7 to 50 m in height, in Qatar and Sinai; (2) the recharge mounds are correlated with the locations of mapped strike-slip and oblique-slip faults; and (3) isotopic composition of the groundwater in these locations indicate significant depletion (δ18O: −9.53‰ to −8.4‰; δ18O: −5.2 to −2.6‰) compared to modern precipitation (δ18O: −3.43‰; δ18O: −0.68‰) in Sinai and Qatar, respectively, which implies limited surface recharge. The mechanism of formation of these groundwater mounds and the amount of upward recharge from the deep aquifers need further investigations to be addressed.

The present paper aims mainly at promoting an environment-friendly method to detect and locate aquifers in a context of effective and sustainable groundwater resources management. Concretely, it is a matter of illustrating how traditional hydrological and modern geophysical methods can be used conjointly to characterize aquifers. Main hydrodynamic characteristics of the Pan-African aquifer obtained in this survey could be observed in all regions worldwide where the Pan-African geological setting is extended. And this environment-friendly approach, using conjointly geophysical and hydrological methods, can be used to explore aquifers elsewhere in the context of sustainable management of groundwater resources.

Northeastern Algeria has been known, since ancient times, by the presence of thermo-mineral springs emerging from different geological formations, especially in the vicinity of the Tunisian borderline. These hot waters circulate along the fractured system and the main thermal spring emerges from a Neogene graben. Each of the four inventoried hot springs has at least three griffins. These thermal waters are found to be saline and carbo-gaseous. The geochemical facies are of the Cl–HCO3–Na type. Stable isotopes contents (δ2H, δ18O) showed that the waters are of meteoric origin. Strontium isotopic ratios 87Sr/86Sr indicated the presence of a mixture of thermal fluids with infiltrated meteoric waters at shallow depths as well as strong water-rock interactions. The combined use of geochemical and isotopic tracers highlights the existence of a hydrothermal alteration and a saline fluid circulation.

Livelihood in agro-based Barind area in northwest Bangladesh is at risk due to moderate-extreme drought impacts. Assessment of water governance status is carried out considering the blue water footprint (WF). Here, the cropping pattern is dominated by rice and the majority of the farmers use groundwater for irrigation. Among crop varieties, Boro rice accounts for the highest WF (3109 l/kg) consuming 70% of water with little economic return, and all crops exceed global WF standards. The performance indicators like transparency, accountability, participation, social equity, environmental integrity, efficiency and effectiveness of government organizations (BMDA, BWDB, DPHE and LGED) and NGOs (DASCOH Foundation) show that the performance of DASCOH Foundation was ‘good’; BMDA and LGED ‘moderate’; while BWDB and DPHE ‘bad’, and should take rigorous action plans for scaling up in these issues. DASCOH Foundation has started to institutionalize IWRM, updating water laws etc. So, appropriate strategies for governance performance due to sustainable resource management should be given priority with enabling environment, institutions, and instruments.

Irrigation water quality in semiarid areas of North Algeria is degrading because of contaminants originating from anthropogenic sources. Among these harmful contaminants, nitrate and phosphate ions are the most common. In this context, this study was carried out to assess the contamination degree of irrigation water, with a particular emphasis on nitrate and phosphate enrichment in the groundwater of Hennaya alluvial aquifer and surface water of Sikkak wadi. Surface and groundwater samples were collected, during April and November in 2017 and analyzed. The concerned physicochemical parameters were pH, Temperature (T), Electrical conductivity (EC), Total Dissolved Solids (TDS), Chloride (Cl−), Nitrate ( $${{\text{NO}}_{3}}^{ - }$$ NO 3 - ) and Phosphate ( $${{\text{PO}}_{4}}^{3 - }$$ PO 4 3 - ). The obtained results were compared to irrigation water quality guidelines. All groundwater samples showed that nitrate concentrations were distinctly higher (up to 98 mg/L) than the guideline values of irrigation water quality (30 mg/L). Phosphate contents were observed in 3 wells in which they attained the maximal value of 0.42 mg/L. These high concentrations in nutrients (Nitrate and phosphate) originated from an excessive use of agrochemicals, when penetrating the soil and reaching the groundwater.

The aim of this study is to evaluate the dam’s water quality of North-Central Algeria. The water quality data was monitored at twenty different dams, between January and December of 2017, using 9 water quality parameters and a multivariate analysis such as Cluster Analysis (CA). The CA allowed the formation of five clusters between the sampling sites, reflecting differences between the water quality at different locations. The Ghrib and Herraza Dams were characterized by a strong mineralization with a concentration of total solids of more than 1600 mg L−1, reflecting the geological nature of the watershed.

Boukourdane dam in Northern Algeria plays a fundamental role in the local society as a source of irrigation and drinking water. In order to characterize the temporal variability of water quality in the dam lake, monthly monitoring was conducted for a period of 2 years (January 2013–January 2015) at four sites. The water in the dam tended to be alkaline, with the highest pH = 9.95 recorded in the spring of 2013. The highest value of temperature was recorded in summer (37.6 °C). The dissolved oxygen levels varied between 2.58 and 11.61 mg L−1. Nitrates were low and the fecal coliform ranged between 85.60 and 1099.67 UFC mL−1. The overall water quality in the Boukourdane dam is medium to good according to SEQ-EAU (Normes de qualité des eaux des masses d’eau naturelles [4]). To confirm these results, we calculated the water quality index (WQI); during the study period, the WQI varied between 60 and 72. The water quality is frequently impaired; conditions often depart from desirable levels which classified the water quality as medium. There was a general trend of decrease in the summer and autumn of 2014 and this is the result of natural processes (degradation of organic matter as well as the concentration of nutrients in those seasons).

Groundwater quality is continuously getting polluted due to the increasing human activities and the rapid growth of urbanization in and around a tannery belt of Southern India, where around 80 functioning tanneries are discharging untreated effluents into open land and channels. Detecting and evaluating the effects of industrial and human activities are keys to finding the hydrochemical backgrounds and drinking water suitability. Thus, this paper deals with the cumulative probability distribution of analytical hydrochemical data, which was adopted to estimate the backgrounds on groundwater quality as well as quantify its abnormality. Results show two types of threshold values. The first threshold values of TDS, Ca2+, Mg2+, Na+ and K+ ions are estimated at about 906, 182, 60, 160 and 5 mg/l, respectively, whereas 191, 280, 109 and 12 mg/l for Cl−, $${{\text{HCO}}_{3}}^{ - }$$ HCO 3 - , $${{\text{SO}}_{4}}^{2 - }$$ SO 4 2 - and $${{\text{NO}}_{3}}^{ - }$$ NO 3 - ions. They directly indicate the background levels of these ions. The second threshold values indicate the strong influence areas, mainly distributed in and around the tannery clusters. Furthermore, Water Quality Index (WQI) shows that there is no excellent groundwater type but about 59% of the samples are of poor quality for drinking water use.

The watershed Cheliff-Ghrib undergoes important anthropogenic pressures which mainly affect the river of Cheliff and the Ghrib reservoir. Dammed water is used, without preliminary treatment, for farm irrigation. This work is a biological characterization of the quality of water of the Ghrib Dam. Surface water samples were taken monthly (2014–2016) from 3 sites from the dam. We determined Species Richness (Margalef’s diversity index) as well as biological quality using saprobity index. By qualitative and quantitative analysis of the zooplankton community, 51 bio-indicator species were recorded from 3 groups in the dam. The results of the saprobity index show that the water quality is between Oligo to Beta Mesosaprobic (very slight pollution to moderate pollution). Thus, any change or altering in the water body due to anthropogenic activities, agricultural runoff and various other factors, accounts for the increase or decrease in physi-cochemical parameters, which in turn results in the change of the zooplankton composition in the Ghrib Dam.

Due to the developments in the field of computer sciences, numerous models have recently been developed for hydrodynamic and water quality assessment in water-bodies. Among these models, the two-dimensional laterally averaged CE-QUAL-W2 has received considerable attention worldwide and has become a commercial model in the recent decade. Considering the model’s abilities and the need to study the Doosti dam, the present study examines the water quality parameters of the Doosti dam Reservoir, such as phosphorus, Nitrate, etc., over a year-long period. The model was calibrated and yielded satisfying results, especially in the case of water temperature. Here, the results for the period from 2013 to 2014 have been presented. The results showed a three-month thermal stratification in the reservoir. Also, results of quality parameters showed that the Doosti dam reservoir is in danger of eutrophication.

Flooding is a natural phenomenon, which constitutes a threat that could lead to loss of human life and material property. It constitutes the first major risk. During the last years, artificial intelligence has been widely applied in the field of hydrology and in many other fields of hydraulic engineering. The Hilbert-Huang Transform (HHT) is a new signal processing technique in the analysis of non-stationary time series, particularly effective for hydrological series. Currently, the application of intelligent hybrid systems in different areas has shown a good performance and an unequalled efficiency. As such, the hybrid technique of an adaptive neuro-fuzzy inference system (ANFIS) coupled to the Hilbert-Huang transform (HHT-ANFIS), was used in this study to estimate daily flow rates in Algiers’ coastal basin. The results obtained are very encouraging and more efficient than those obtained by the neuro-fuzzy inference model and the classical multiple linear regression (MLR) model.

Floodline estimation was approached from an integrated developmental view-point in this study. The objective was to determine areas prone to flooding. This was done to serve as an early warning mechanism to support planning and development. The paper estimates the design flood with various return periods for the sub-catchment. Investigations integrated together to derive the floodline areas were the geographical information system (GIS), extraction of catchment properties from Google earth maps, digital elevation models (DEM), modelling using hydrological engineering center and river analysis system (HEC RAS). Delineated catchment parameters show that the Brandfort sub-catchment area covers 48.63 km2, while the channel length is 7.124 km. The channel slope is 0.489% indicating a flat and flood-prone region. 1:50 years and 1:100 years floodline modelling shows that larger areas of the catchment have the potential of being flooded. The significance of the study suggests that by using an integrated approach, floodline delineation can serve as an early warning tool for proper flood management in order to prevent future disasters.

In this research, the effects of the development of Mashhad city (in Iran) on the amount of runoff generated were investigated. The urban catchment of this city with a total area of 328 km2 was divided into 288 sub-catchments, 399 waterways, 398 nodes, and 5 outlets using GIS software. The pervious, impervious, residential, agricultural and street areas were then determined using the GIS software and Google Earth. The Curve Number (CN) was calculated for each sub-catchment. Three different methods of periodic block, uniform distribution and SCS (CN) II were used for selection of the storm discharges. Finally, the SCS (CN) II method was selected. The results of the modelling showed that the peak of flood in 2016 was 307, 259 and 177% greater than the years 1941, 1976 and 1986, respectively. In addition, the results showed that the central, northern, and northeastern regions (downstream of the city) were flooded due to the increase of the impervious surfaces and the insufficient capacity of the channels.

Extreme rainfall and pluvial flood hazard has recently occurred in Alexandria and caused large human and economic losses. In this regard, the urban green infrastructure (UGI) is considered as a sustainable alternative to urban water management with different applications to reduce water accumulation in the streets caused by the inadequate drainage network capacity. This paper aims at demonstrating an assessment approach to prioritizing urban areas where UGI should be applied. The proposed method integrates flood modeling and land use classification into an assessment index called the UGI Priority Index. This index can help determine the neediest areas for UGI implementation alternatives to reduce the amount of accumulated rain. The introduced priority map can help the decision makers to direct the development plans to the priority areas and reduce the pluvial flood risk level using environmentally-friendly options.

Rapid urbanization in the 5th settlement—Cairo, Egypt, led to a dramatic impact on the hydrological parameters within the area, due to a reduction in the soil infiltration, and consequently increased runoff volumes. Many researches were conducted for similar cases throughout the world to assess the urbanization hydrological impact. In the current study, remote sensing raster classification is utilized to assess the land use and associated Curve Number (CN) variation within the study area, and the SCS method was used to estimate the runoff volume. A Long-Term Hydrologic Impact Assessment (LTHIA) GIS tool has been developed to assess the temporal variation of hydrological parameters through different stages of development from 2006 to 2016 in the study area. It was concluded that during 10 years of development, the impervious areas increased and covered 30% of the study catchment area, the runoff volume increased by about 800% more than the 2006 base line runoff. This study clearly shows the excessive increase in runoff due to urban development and raises the flag for the urban planners at this area, particularly the New Administrative Capital in Egypt which lies along the extent of the 5th district to take necessary flood mitigation measures into account.

Groundwater within the Central University of Technology (CUT), Bloemfontein, was investigated in order to determine its hydraulic and hydrochemical characteristics with potentials for urban water supply. The investigations involved carrying out pump yield tests on three boreholes on the CUT campus. Further examination involved laboratory testing of the groundwater for chemical signature, and geophysical investigation to determine the geological and aquifer target of the boreholes using an electrical resistivity tomography (ERT). Additionally, electrical conductivity profiling (EC Profiling) was used to detect the fracture positions within the boreholes. Pumped test results monitored from the three boreholes were interpreted using FC (flow characteristics) software program. Cooper-Jacobs and Basic FC methods from this software recommend a sustainable yield of 7.83–9.34 l/s, respectively, while storativity values are 7.93 × 100 for Cooper Jacobs and 2.2 × 10−3 for Basic FC method. Hydrochemical analysis shows Mg-HCO3 water type from Stiff diagram. This shows dissolved solutes from rainfall and the host rocks, but not from urban activities. The results of the fracture positions at an ambient state in the wells were 5, 6 and 9.5 mbgl in boreholes 1, 2 and 3, respectively. The geohydrological characteristics displayed by the groundwater of the CUT campus relate to the general characteristics of the Karoo aquifers.

Most of the countries in the eastern Mediterranean region, including Palestine, are characterized by arid to semi-arid climatic conditions and have limited water resources. This work aims at applying the Geographical Information Systems (GIS) to assess the suitability of proposed dam sites for the construction of earth dams to mitigate flood flows in the Sanour area in Jenin district, north of the West Bank, Palestine. The GIS techniques were utilized in site mapping and characterization to assess different criteria including delineation of drainage network and watershed boundaries, geology, soil, topography, and land use. ArcHydro tools, ArcGIS and SCS-CN methods were employed to model rainfall-runoff on a sub-catchment basis. For the rainy season of 2009/2010, the total runoff of stream network was estimated at about 1.57 million m3. Eventually, two selected dam locations were suggested for flash flood controls. Total rainwater harvesting of about 270,000 m3 is estimated from the two proposed dam sites. This water will also be of great importance to meet the rising demand for agriculture uses and expansion in reclamation.

Dokan reservoir is located on the Lesser Zab River NE Iraq. Its drainage area is 11,690 km2 with a storage capacity of 6.87 × 109 m3. Calculation of the volume of the reservoir before the construction of the dam and from the bathymetric survey conducted in 2014 indicates that an annual average of 7 million cubic meters of sediments are deposited within the reservoir. This reduced the storage capacity of the reservoir by 28%.

This paper describes the research example of the impact of organics on the behavior of heavy metals in the aquifers in the zone of the influence of the municipal solid waste landfill in the Moscow region. The aim of the study is to clarify the factors of groundwater contamination by heavy metals after recultivation in order to develop environmental protection measures. The obtained results allowed to identify the hazard of landfill as a source of contamination by heavy metals, to clarify the main stage of organic decomposition (in the top part–active stable methanogenesis and in the lower part–stable methanogenesis), and to determine the present stage of redox zoning development (the formation of the reduction zone of iron compounds contained in the solid phase water-bearing rocks, accompanied by the release of nickel and cobalt, previously adsorbed on iron and magnesium oxides and hydroxides).

Wastes are dumped in the main Tanjero landfill site from different sources, such as domestic waste and uncontrolled waste dumping from the refineries in the area. The BTEX complex has been recognized in the analyses of the groundwater sample in some wells around the Tanjero waste dump site. Benzene and toluene were the two main components with significant concentrations compared with the other components of BTEX. In this study, the variation in the concentration of benzene and toluene was simulated in different depths for 25 years. The modeling of the benzene and toluene scenario is correlated with regard to the climate conditions as well as physical and chemical conditions of the soil in the waste dump site. The contamination can reach the groundwater but in low concentration and inversely with the depth. Different phases of contaminants in the unsaturated zone in the subsoil show different rates of contamination, depending on the phase type (gas, liquid and solid). The contamination potentials of benzene and toluene are different in the rates, and toluene has more concentration in the liquid phase than benzene in the unsaturated and saturated zones. Benzene is attenuated more rapidly than toluene in this area. The current study aims to evaluate the potential impact of BTEX contamination on the groundwater.

This study aimed to analyze the economic profitability of irrigation under hydrological risk. Towards this end, two hill lakes located in different climatic conditions (sub-humid and semi-arid climates) were selected and a chance constraint linear programming model was used. The model incorporated the uncertainty of water supply at exceedance probability of 80, 90, 95 and 99%. The results showed that in a sub-humid climate, there are 100 and 95% chances to meet monthly water requirements for winter and summer crops, respectively. The impact of a small dam on local farming economic profitability was highly significant. Both environmental and socio-economic objectives can be achieved. In a semi-arid climate, results showed that, at the 90% water supply reliability, only winter crops and olive trees were included in the optimal cropping pattern under deficit irrigation and on a limited area. Summer crops were not recommended. The economic profitability of irrigation around the small dam would be strongly reduced. Therefore, the objective to improve the population well-being in arid and semi-arid regions assigned to these structures is not likely to be achieved. As the public budget allocated to environment protection becomes more and more restraint, this study suggests implementing hill lakes first in areas where their economic and environmental efficiency is proven.

In a virtual absence of effective regulation, the large scale adoption of surface wells in the Center of Tunisia have led to enormous extraction rates of groundwater, often exceeding natural recharge rates. To overcome the negative impact of groundwater depletion, farmers adopt in general several coping strategies. This study aimed to identify the type of strategies adopted and to quantify their potential to mitigate the negative impact on farmers’ income. To this end a survey was undertaken over 95 small farmers, owning less than 5 ha and using surface well for irrigation. A linear programming model was applied to a representative farm. Results showed that as a first step, farmers act on crops selection and agriculture practices so to minimize the impact of water shortage. However, this implies losses in farmer’s income. This study suggests that, even though there are some successes, adaptive strategies should be considered as “short-term panaceas” and not a sustainable solution, as they are not able to prevent further losses in farmer’s income directly resulting from overexploitation and increasing pumping cost.