Hydrogeological and Hydrogeochemical Insights into Groundwater Mineralization: A Spatiotemporal Analysis of the Terminal Complex Aquifer in Wadi Righ, Southern Algeria

To manage groundwater resources and develop an action plan, it is crucial to understand the long-term behavior of groundwater level (GWL) fluctuations. In this study, Geographic Information System (GIS) and non-parametric statistical tests were applied for detecting long-term (1973 to 2020) spatio-temporal variations and trends in GWL from 137 observation wells evenly distributed across the south-western part of Punjab. This region has experienced significant changes in GWL over the decades. The non-parametric statistical tests included Mann-Kendall (MK), Sens's SlopeEstimator (SSE), and Innovative Trend Analysis (ITA). The study observed significant trends in GWL fluctuations before and after monsoon. The MK and SSE tests showed a statistically increasing trend in observation wells with about 65.7% and 67.2% increase before and after monsoon, respectively. The innovative trend analysis (ITA) also revealed a statistically increasing trend in observation wells with an increase of about 63.5% and 65.7% pre and post-monsoon season, respectively. The results indicate lowering of GWL in the northern districts of southwestern Punjab, while the southern districts experience rising GWLs. This discrepancy can be attributed to diverse agricultural activities and reduced over-exploitation of groundwater in the southern district due to soil salinity and the presence of brackish groundwater. These findings provide valuable insights into the dynamics of GWL in the studied region, highlighting notable trends associated with seasonal variations.

Hydrochemistry and isotope compositions of groundwater from the Shihongtan sandstone-hosted uranium deposit, Xinjiang, NW China

This research focuses on determination of irrigation — drainage networks conditions, salinity of irrigated areas in Shavat district of Khorezm region (Uzbekistan) by geospatial analysis and giving recommendations for their elimination. Additionally, obtaining monthly ground truth data from observation wells and interpolate them with IDW interpolation algorithm methods of Geographic Information Systems (GIS) technologies in order to monitoring changes of groundwater level and mineralization in vegetation period of main agricultural crops are highlighted. Besides that, by using remote sensing technologies, the obtained data about the irrigation regime was determined in agricultural areas. As a result of the usage of GIS and RS methods, there have been created thematic maps on analysing salinity of soils, the actual condition of irrigation and collector of networks, actual level and mineralization of groundwater as well as their dynamic changes. On the basis of the obtained results, there have been given recommendations for improving the conditions of ameliorative arable lands on keeping the level of groundwater at a specified depth and cultivation of agricultural crops in periods of water scarcity.

Groundwater in the coastal area is relatively vulnerable to the contamination by seawater intrusion, which makes it unsuitable for drinking or irrigation. This study was carried out along the coastal aquifer of southern Tamil Nadu, India. To access the impact of mining, the coast was divided into three sites, namely (i) non-placer sand area, (ii) active mining area and (iii) inland dune area. The non-placer sand area is assumed to be undisturbed and is considered as reference site. The inland dunes sand area is the area with no active mining but within the impact of the mining activity. Hydrogeochemical and groundwater table characteristics of shallow coastal aquifer system in the mining and non-mining area were investigated to identify the salinization process. The Na/Cl ratio, correlation matrix and ionic relationship between major ions showed a marked increase in salinization in the active mining area and nearby wells. The reverse ion exchange and seawater intrusion control the groundwater chemistry along the active mining aquifers. The spatial visualization of electrical conductivity, salinity, chloride and groundwater quality index map (GWQI) that reflects active mining areas are exhibiting poor water quality and are comparatively low in non-placer mining areas. Gibb’s diagram representing evaporation is the dominant process more than the rock water interaction and precipitation. The groundwater level fluctuation in both inland dune and non-placer sand area aquifers blocks a little variation due to lack of rainfall, irrespective of volumes of water recharge and over pumping of groundwater for irrigational purposes. In the active mining region, the groundwater level shows high fluctuation of ±3 to ±5 m below the ground level. Depth profile study indicates the highly depleted groundwater level in the active mining region that has induced higher EC value and salinity. The process might, therefore, be related to the saltwater encroachments. Tidal induces changes in water level in the Karamaniyar river estuary and near the active mining wells around 1.03 m and the Vembar river estuary water level increased in the wells around 0.68 m.

Spatio-temporal evolution and simulation of soil salinization in typical oasis water-saving irrigation area based on long series data

Groundwater is a major source of supply for domestic and agricultural purposes, especially in arid and semi-arid regions. In this study, we followed the variations in water levels in the Souf oasis in the Algerian Sahara by measuring depths to groundwater across 65 points during the period from 2010 to 2015. Additionally, electrical conductivity (EC) was measured for assessing variations in groundwater salinity in the same groundwater monitoring network over the same time interval. The results from these investigations indicated that there are significant and continuous declines in the groundwater level across all study areas throughout the period of investigation. This is especially the case in the northern part of the study area where the water table declined by up to 18.2 m in Ghamra in 2015. Additionally, this study has indicated that the rate of decline of groundwater levels has increased from 0.29 m/year as an average in 2011 to 2.37 m/year in 2015, where the situation has become alarming. As a consequence of this, the depth to groundwater now exceeds 2 m over more than 77% of the study area, and only about 17% of the study area now has a water table depth that lies within the optimal depth interval for extractive uses (between 1 and 2 m). This decline in groundwater levels has been accompanied by a significant increase in the electrical conductivity values (salinity) of this water, and there is a strong correlation between these variables (R > 0.99). This alarming situation has been caused by the continuous over-exploitation and unsustainable management of this limited resource, especially by the agricultural sector. For a long time, this critical situation led to the demise of the agricultural world heritage cultivation system (Ghout) due to the increasing salinity of groundwater. Two solutions are proposed to manage the effects of groundwater depletion in the area: firstly, rationalizing groundwater use through effective groundwater allocation management measures, and secondly by implementing the reuse of treated wastewater as an alternative water source for agricultural use. This latter measure could be in two ways: either by direct use in irrigation to relieve pressure on the phreatic aquifer, or by artificial recharge of the phreatic aquifer.

With the intensification of human activities, the water resource environment in the karst mountainous area of central Shandong has undergone significant changes, directly manifested in the cessation of karst spring flows and the occurrence of karst collapses within the spring basin in the Laiwu Basin. To support the scientific development and management of karst water, this study utilizes comprehensive analysis and deuterium-oxygen isotope test data from surveys and sampling of 20 typical karst springs conducted between 2016 and 2018. By integrating mathematical statistics, correlation analysis, and ion component ratio methods, the study analyzes the genesis, hydrochemical ion component sources, and controlling factors of typical karst springs in the Laiwu Basin. The results indicate that the genesis of karst springs in the Laiwu Basin is controlled by three factors: faults, rock masses, and lithology, and can be classified into four types: water resistance controlled by lithology, by faults, by basement, and by rock mass. The karst springs are generally weakly alkaline freshwater, with the main ion components being HCO3− and Ca2+, accounting for approximately 55.02% and 71.52% of the anion and cation components, respectively; about 50% of the sampling points have a hydrochemical type of HCO3·SO4-Ca·Mg. Stable isotope (δ18O and δD) results show that atmospheric precipitation is the primary recharge source for karst springs in the Laiwu Basin. There are varying degrees of evaporative fractionation and water–rock interaction during the groundwater flow process, resulting in significantly higher deuterium excess (d-excess) in the sampling points on the southern side of the basin compared to the northern side, indicating clear differentiation. The hydrochemical composition of the karst groundwater system is predominantly governed by water–rock interactions during flow processes and anthropogenic influences. Carbonate dissolution (primarily calcite) serves as the principal source of HCO3−, SO42−, Ca2+, and Mg2+, while evaporite dissolution and reverse cation exchange contribute to the slight enrichment of Ca2+ and Mg2+ alongside depletion of Na+ and K+ in spring waters. Saturation indices (SI) reveal that spring waters are saturated with respect to gypsum, aragonite, calcite, and dolomite, but undersaturated for halite. The mixing of urban domestic sewage, agricultural planting activities, and the use of manure also contributes to the formation of Cl− and NO3− ions in karst springs.

Understanding groundwater geochemical evolution is crucial for sustainable water management, particularly in Algeria's semi-arid regions, where water scarcity is a major challenge. Sixty-five groundwater samples were collected and analyzed in March 2021 from the study area to identify hydrogeochemical processes, water–rock interactions, and groundwater suitability for drinking and irrigation. Results indicate significant variations in mineralization, with over 90% of samples highly mineralized, reaching 31,700 µS/cm. The abundance of major ions was Na2+ > Ca2+ > Mg2+ > K+ for cations and Cl− > HCO3− > SO42− > NO32− for anions. Most samples are classified as very hard-brackish or hard-brackish, with Ca-Mg-Cl-SO4, Na-Cl, and Ca-Mg-HCO3 as the main water types. The increase in salinity is primarily due to geogenic processes, with some anthropogenic influence. Water–rock interactions and evaporation are the key factors controlling groundwater chemistry, with the dissolution of halite, gypsum, anhydrite, calcite, and dolomite playing a major role. Additionally, cation exchange and silicate weathering are prevalent processes in the groundwater system. Saturation index analysis reveals that anhydrite, gypsum, and halite are unsaturated, whereas aragonite, dolomite, and calcite are saturated. Regarding usability, over 73% of groundwater samples require treatment before drinking, while more than 80% are suitable for irrigation.

The rapidly changing climatic scenario is demanding periodic evaluation of groundwater quality at the temporal and spatial scale in any region for its effectual management. The statistical, geographic information system (GIS), geostatistical, and map overlay approaches were applied for investigating the spatio-temporal variation in groundwater quality and level data of 242 monitoring wells in Punjab, Pakistan during pre-monsoon and post-monsoon seasons of the years 2015 and 2016. The analysis indicated the higher variation in data for both the seasons (pre-monsoon and post-monsoon) as coefficient of variation (CV) values were found in the range of 84–175% for groundwater quality parameters. Based on the t-test values, the marginal improvement in groundwater electrical conductivity (EC), sodium absorption ratio (SAR) and residual sodium carbonate (RSC) and decrease in groundwater level (GWL) were observed in 2016 as compared to 2015 (p = 0.05). The spatial distribution analysis of groundwater EC, SAR and RSC indicated that the groundwater quality was unfit for irrigation in the lower south-east part of the study area. The groundwater level (GWL) was also higher in that part of the study area during the pre-monsoon and post-monsoon seasons in 2015 and 2016. The overlay analysis also indicated that the groundwater EC, RSC and GWL values were higher in south-east parts of the study area during pre-monsoon and post-monsoon seasons of 2015 and 2016. Hence, there is an instant need to apply groundwater management practices in the rest of the region (especially in the lower south-east part) to overcome the future degradation of groundwater quality.

Huzur Tehsil, district Bhopal city in the Madhya Pradesh state of India has faced the problem of groundwater availability in recent times believed largely due to rapid urbanization coupled with the presence of increasing Population and the urban sprawl increase the number of bores well in earth, which is the reason to the declination of groundwater level. That means water is very important for the sustained use of natural resources and is vital for the existence of mankind. Groundwater used for a variety of purposes, including irrigation, drinking, and manufacturing. For assessing the groundwater Level suitability zones through GIS techniques, this study was undertaken in the Huzur Tehsil, Bhopal district, Madhya Pradesh. Artificial recharge is expected to become increasingly necessary in the future as the growing population requires more water and thus, more storage is required to conserve water for use in times of shortage. Geospatial techniques employing Geographical information systems (GIS) are increasingly being used in the field of hydrology and water resources development. This is the greatest advantage of using GIS techniques for Groundwater level (bore well) investigations and monitoring is its ability to generate information in water level behavioral conditions, which is provided very critical for successful analysis, prediction, and validation. In the present study, the Kriging technique was used to interpolate the groundwater levels. Interpolation of pre and postmonsoon groundwater levels was carried out for the year 1996-2017. Finally, we generated the fluctuation maps were showing the fluctuation in the pre-post monsoon period between the years, 1996-2000, 2001-2005, -2010 and 2011-2017 and Long term trend fluctuation maps were generated showing, and finally, Feature Projected Groundwater Level map are generated 2018-2051 period, and showing the Groundwater Level trend (1996-2051) since. For visualization groundwater level depth (mbgl) and Fluctuation, in the pre and post-monsoon period, showing the 3D Surface modeling using Matlab tools. DOI: https://doi.org/10.23953/cloud.ijarsg.455

The multi-aquifer system of the Dakhla region, in the hyper-arid Atlantic Sahara, was investigated to understand the primary recharge mechanisms and identify the sources contributing to the groundwater salinization. Groundwater samples were collected and analyzed for their chemical and stable isotopes (δ2H and δ18 O) composition. The results show that the groundwater quality ranges from brackish (up to 4700 µS/cm) to saline (15,810 µS/cm). Ionic ratios and saturation indices indicate that evaporite dissolution is the primary process driving groundwater mineralization, whereas the Cl-/Br- molar ratio demonstrates that saline intrusion is negligible. Water isotopes reveal two distinct groundwater types: paleo-recharged water in the deeper aquifers and modern meteoric water in the shallow aquifers. Overall, salinization is mainly governed by water-rock interactions under thermal effect, coupled with ion exchange and rock weathering across all aquifers. Additionally, groundwater in the Plio-Quaternary aquifer shows signs of evaporation before infiltration. These processes collectively degrade the groundwater quality, rendering it unsuitable for domestic and agricultural uses. This study presents the first hydrogeochemical model in the region, establishing a scientific foundation for sustainable groundwater management and protection against overexploitation and pollution in the Dakhla coastal area.

Groundwater is a key component of the water cycle in arid ecosystems due to low precipitation,high surface runoff and high evaporative demand.It has a direct influence on the growth and development of natural vegetation,species diversity,and ecosystem metabolism.This study reports on the variation in groundwater levels and quality in the western region of the Grurbantonggut Desert over three consecutive years.We investigated how groundwater level and quality affect physical and chemical properties of soil,species diversity,and the growth and regeneration of Haloxylon ammodendron.We established 20 inspection wells for measuring groundwater level over a period of three consecutive years.These inspection wells were set up at intervals of 7km to 10km from west to east in longitude and north to south in latitude,which according to the situation of the degenerate and distribution of Haloxylon ammodendron population in the study area.The study area contain habitat which is plain and small and big sand-dunes.The results show that groundwater levels varies widely in this area,ranging from 3.3m to 24.2m,averaging 6m to 8m.The soil physical-chemical factors also vary greatly across this area.Soil EC,pH,Cl-and SO2-4 have higher values at depths of 0cm to 40cm;their coefficients of variation decrease at greater depths.The groundwater level exhibits seasonal variation,influenced by upstream irrigation.The highest and lowest groundwater levels appear in April and July,respectively.The Manas River plays an important role in recharging groundwater in the study area,which of course varies between years.Approximately 75% of the groundwater level found in the inspection wells rises in 2010 compared with last year,which rises seasonally by 4.3cm on average,while the mineralization increases to 1g/L on average.The groundwater level has a weak effect on species diversity in the degraded area,while it has a significant impact on the growth of Haloxylon ammodendron.We find that the suitable groundwater level for growing Haloxylon ammodendron is 5m to 8m and the optimal mineralization level is less than 4g/L.Haloxylon ammodendron populations decline when groundwater level is more than 8m.When the groundwater level is less than 4m,groundwater mineralization causes salt deposition on the soil surface.This reduces the level of species diversity significantly and blocks the regeneration of Haloxylon ammodendron.This in turn leads to declines in the Haloxylon ammodendron population.In summary,the depletion of the Manas River related to agricultural irrigation influences the groundwater levels and the quality of the ecosystem in the western Grurbantonggut Desert.The decline in the Haloxylon ammodendron population is significantly correlated with groundwater levels.This should be considered in future natural resource conservation planning for this area.

The assessment and prediction of water quality are important aspects of water resource management. Therefore, the groundwater (GW) quality of the Nubian Sandstone Aquifer (NSSA) in El Kharga Oasis was evaluated using indexing approaches, such as the drinking water quality index (DWQI) and health index (HI), supported with multivariate analysis, artificial neural network (ANN) models, and geographic information system (GIS) techniques. For this, physical and chemical parameters were measured for 140 GW wells, which indicated Ca–Mg–SO4, mixed Ca–Mg–Cl–SO4, Na–Cl, Ca–Mg–HCO3, and mixed Na–Ca–HCO3 water facies under the influence of silicate weathering, rock–water interactions, and ion exchange processes. The GW in El Kharga Oasis had high levels of heavy metals, particularly iron (Fe) and manganese (Mn), with average concentrations above the limits recommended by the World Health Organization (WHO) for drinking water. The DWQI categorized most of the samples as not suitable for drinking (poor to very poor class), while some samples fell in the good water class. The results of the HI indicated a potential health risk due to the ingestion of water, with the risk being higher for children in only one location. However, for both children and adults, there was a low risk of dermal and ingestion exposure to the water in all locations. The contaminants could be from natural sources, such as minerals leaching from rocks and soil, or from human activities. Based on the results of ANN modeling, ANN-SC-13 was the most accurate prediction model, since it demonstrated the strongest correlation between the best characteristics and the DWQI. For example, this model’s thirteen characteristics were extremely important for predicting DWQI. The R2 value for the training, cross-validation (CV), and test data was 0.99. The ANN-SC-2 model was the best in measuring HI ingestion in adults. The R2 value for the training, CV, and test data was 1.00 for all models. The ANN-SC-2 model was the most accurate at detecting HI dermal in adults (R2 = 0.99, 0.99, and 0.99 for the training, CV, and test data sets, respectively). Finally, the integration of physicochemical parameters, water quality indices (WQIs), and ANN models can help us to understand the quality of GW and its controlling factors, and to implement the necessary measures that prevent outbreaks of various water-borne diseases that are detrimental to human health.

The interaction between surface water and groundwater is a complex process and is considered as an important component for controlling the mining activities. The objective of this study is to understand the interaction between surface water and groundwater around a proposed uranium mining site by geochemical modelling. Surface water and groundwater samples along the groundwater flow path were collected from September 2013 to June 2016 across the uranium mineralised region located near Gogi, Karnataka, India. Collected water samples were analysed for major ion and uranium concentrations. This hydrochemical data was used as input in the geochemical modelling code PHREEQC to calculate the uranium speciation and saturation indices. Inverse geochemical modelling was performed along the flow direction by considering the mineralogical composition of host rock. Measurement of surface water and groundwater level indicates that the recharge and discharge of this region were primarily controlled by rainfall. Relation between the temporal variation of rainfall and saturation index of mineral reveals the various scenarios of interaction between surface water and groundwater around the mineralised region. Silicate/carbonate weathering, irrigation return flow and dissolution of evaporites are the major processes indicated by inverse geochemical modelling, which controls the hydrogeochemical evolution of water in this region. Geochemical modelling was effectively used to understand the temporal changes in the interaction between surface water and the groundwater in a uranium mineralised region.

Salinization processes are taking place as a result of rising groundwater level and its mineralization rate due to inefficient and unsustainable use of water and land resources in Uzbekistan. This leads to a reduction of arable land productivity and a decrease in nationwide yield production. Especially, salinization is the case in the plain irrigated areas of Uzbekistan where the groundwater is closer to the surface. Salinization processes occur as a result of an increase in the level of groundwater and the degree of their mineralization due to inefficient and irrational use of water and land resources in Uzbekistan. This leads to a decrease in the productivity of irrigated land and a decrease in yields throughout the country. Principally, salinization takes place in irrigated plain areas like the Syrdarya province, where mineralized groundwater is closer to the surface. Considering the geo-location of Uzbekistan as an aridic zone, there is a massive stress on groundwater because of surface water shortage. Since the estimation of the salinization consequences on groundwater is critical, this research, therefore, was aimed to understand and evaluate the long-term changing behavior of groundwater level and its mineralization in the irrigated areas of the Syrdarya province of Uzbekistan from 2000 to 2015 by using traditional methods, and GIS-based methods for from 2016 to 2019.The level and mineralization of groundwater in each administrative district of the province were for the first time studied and assessed. Consequently, the dependence of the groundwater level and its mineralization on soil conditions and climatic factors were determined. Based on the results of the study, agricultural specialists and farmers of the province were highly advocated to take the following measures considering the actual condition of groundwater mineralization in the irrigated areas of the Syrdarya province: (1) targeted and economical use of irrigation water; (2) ensuring that existing drainage networks are in an adequate working condition and can operate with full-efficiency; and (3) to conduct annual monitoring of groundwater table and its mineralization of irrigated lands using traditional and GIS technologies.