High Groundwater Potential Zones Research Articles

Developing a new method for future groundwater potentiality mapping under climate change in Bisha watershed, Saudi Arabia

This study proposes a new groundwater potentiality model (GPM) in the Bisha watershed, Saudi Arabia, by integrating logistic-regression (LR)-weighted and fuzzy logic-based ensemble machine learning (EML) models for the present and future scenarios. We applied random forest, bagging, and random subspace models for predicting the GPMs. We also used the general circulation model’s (GCM) minimum and maximum representative concentration pathway (RCP) 2.6 and 8.5 scenarios for the future GWP mapping. Results showed that the bagging hybrid model (Area under Curve: 0.986) outperformed other models. GWP models predicted 4058.57 km2 as very high, 4267.45 km2 as high, 4185.23 km2 as moderate, 4342. km2 as low, and 4430.24 km2 as very low groundwater potential zones. The best model combined with the future climatic conditions shows very high and high groundwater potential zones would cover 2319–2590 km2 and 3100–2795 km2. The current research will aid in the development of long-term sustainable groundwater management plans by increasing the effectiveness of GPMs.

Sustainable Groundwater Potential Zoning with Integrating GIS, Remote Sensing, and AHP Model: A Case from North-Central Bangladesh

Groundwater is one of the most valuable natural resources, and the most dependable source of fresh water. For sustainable groundwater management, the present study aimed to model groundwater potential zones in the north–central region of Bangladesh using GIS, remote sensing, and the analytical hierarchy process. The present study included eight thematic layers: lineament density, geomorphology, soil types, slope, land use/land cover, drainage density, elevation, and rainfall features to delineate a groundwater potential zone of the area. Integration of the eight thematic layers was performed through weighted overlay analysis, which assisted in delineating groundwater potential zones. This simple and systematic method successfully provides a satisfactory result concerning the delineation of groundwater potential zones. The study resulted in a groundwater potential zone map, which identifies about 11.51% of the study area as being under a very high groundwater potential zone, covering an area of 504.09 km2. The AHP analysis shows that the physiographical parameters, such as lineament density, slope, and drainage density, and meteorological factors such as annual rainfall, have greater influence over groundwater potentiality. The result obtained from the weighted overlay analysis was verified with actual well yield and groundwater depth data, which show a significant positive correlation. The outcome of the study will help in taking effective measures to ensure sustainable use and extraction of groundwater in this region.

Multi-criteria decision making and Dempster-Shafer model-based delineation of groundwater prospect zones from a semi-arid environment.

The present study illustrates the delineation of the groundwater potential zones in one of the most critical and drought-affected areas under Bundelkhand region of Uttar Pradesh (India). Hydrological evaluations were carried out using GIS tools and remote sensing data which ultimately yielded several thematic maps, such as lineament density, land use/land cover, drainage density, lithology, slope, geomorphology, topographic wetness index (TWI), DEM, and soil. Thematic layers were assigned relative weightages as per their groundwater potential prospects under multi-criteria decision making (MCDM) method through analytical hierarchy process (AHP). To recognize the groundwater potential zone, weighted overlay analysis was also performed. Additionally, for testing of the Dempster-Shafer model, 16 wells in the study area have been selected. Based on the probability of the groundwater occurrence, the belief factor was equated to delineate groundwater potential zones which illustrate five different potential zones. According to the AHP model, the northwest side of the study area is characterized with very high potential zones whereas the northeast and southeast regions constitute medium and low groundwater potential zones respectively. According to the DS model, very high groundwater potential zones constitute 17% and the remaining area falls under low potential. Overall accuracy of the DS model is higher than AHP model.

Delineation of Groundwater Potential Zones (GWPZ) of Port Blair, Andaman Islands, India, using Multi Influencing Factors (MIF) method and geospatial techniques

This study intended to delineate the groundwater potential zones (GWPZ) of Port Blair and its surrounding areas using the Multi Influencing Factor (MIF) method and geospatial techniques. Multiple data such as geology, geomorphology, slope, soil, drainage density, lineament density, rainfall, NDVI, and LULC were considered for delineating GWPZ. Spatially distributed maps/thematic layers of all the factors mentioned above were prepared using remotely sensed data and by using ground data. These thematic layers were allotted weights after referring to previous literature and study and by considering each layer's influence on groundwater. Finally, all the thematic layers were integrated, and overlay analysis was done to produce a map showing the GWPZ of Port Blair and its surrounding areas. The result (map) was categorized into high, medium, and low groundwater potential zones. This study shows that most of Port Blair's areas come under the medium GWPZ (63.4% of the study area), followed by high GWPZ (27% of the study area), and 10.6% of the area comes under low GWPZ. The most important and innovative part of this study is the physical verification of all the results obtained from the remote sensing and GIS techniques. The GWPZ map was compared with existing well discharge data and validated through the ROC curve, and it shows the study has “very good” accuracy. Finally, this study provides an expedient approach to delineate the GWPZ for practicable management and use of groundwater resources of the area to maintain the sustainability of this island.

A HYBRID GIS AND KNOWLEDGE-DRIVEN APPROACH FOR WATER RESOURCES POTENTIAL ZONATION

Assessing the potential zone of groundwater is extremely important in areas that are prone to climate-related hazards and have limited access to potable water supply such as Kuala Krai, Kelantan, Malaysia. The application of GIS and remote sensing allows for faster, cheaper, and more efficient groundwater management and exploration. In this work GIS and Knowledge-Driven approach are combined in an attempt to identify groundwater potential zones in Kuala Krai. The various thematic maps prepared for delineating groundwater potential zones are lineament, lithology, soil, land use, rainfall, slope, drainage density, and elevation. The knowledge-driven technique is used to assign weights for each factor and Weighted Linear Combination (WLC) approach is used to investigate several choice possibilities and evaluate suitability according to the associated weight of each factor. The results revealed that 31.64% and 15.10% of the area in Kuala Krai were categorized as high and very high groundwater potential zones which are mostly located in the central, western, and southern parts of Kuala Krai where interbedded sandstone, siltstone, and shale were the major geological unit. Furthermore, rainfall was also highly influential in determining groundwater potentiality. In terms of land use, forest, rubber, and oil palm were found to be suitable for high potential zones of groundwater. Moreover, the area located nearby the Kelantan River also exhibited high groundwater potentiality. The map can be used to develop and further expand groundwater utilization in Malaysia.

Groundwater potential zones identification in Arba Minch town, Rift Valley, Ethiopia, using geospatial and AHP tools

Groundwater is a vital natural resource that supports human needs, promotes industrial development, needs farming activities, and helps to maintain ecological balance. Geospatial technologies play an essential role in monitoring, assessing, and conserving groundwater resources. The present study was carried out at Arba Minch town, Rift Valley, southern Ethiopia. A total of eight important groundwater controlling parameters, such as lithology, geomorphology, lineament density, land-use/land cover, slope, precipitation, drainage density, and soil type, were considered to identify suitable groundwater potential zones. The analytical hierarchy process (AHP) technique was used to derive the standard weights for each parameter and its sub-parameters, emphasizing the relative importance of contributing parameters and sub-parameters for groundwater recharge. The present study’s potential groundwater zonation map was divided into three categories: poor, medium, and high. The output has shown about 36%, 24%, and 40% area falls under high, medium, and poor groundwater potential zones. Furthermore, the findings were validated using groundwater level data, which showed a strong correlation. The current study results showed the effect of geospatial techniques and the AHP method in groundwater potential mapping.

Geospatial mapping of groundwater potential zones using multi-criteria decision-making AHP approach in a hardrock basaltic terrain in India

Among all other natural resources, groundwater is one of the most essential for environmental, biological, and socioeconomic activities. Several factors such as geology, distance from the river, geomorphology, slope, land-use, drainage density, lineament density, soil, and rainfall influence groundwater recharge and its availability. In this study, an integrated approach of Geographical Information System (GIS) based Multi-Criteria Decision Making (MCDM), Analytical Hierarchy Process (AHP), and remote sensing were used for geospatial mapping of groundwater. For the determination of influencing factors, an extensive literature review was considered to form a pairwise comparison matrix (PCM) and calculate the weight of each factor. The scores of the sub-parameters were also assigned based on published literature, and after that, the weighted overlay analysis (WOA) tool in ArcGIS10.1 was used to produce the final groundwater potential map. About 14% (684 km2) of the study area is recognized as ‘high groundwater potential zone’, 34% (1591 km2) in ‘moderate groundwater potential zone’, 27% (1291 km2) in ‘low groundwater potential zone’ and the remaining 24% (1141 km2) in ‘poor groundwater potential zone’. In the accuracy assessment, the groundwater potential zones i.e. high, moderate, and poor in suitability map is precisely estimated contrasting to the zone ‘low’ in the producer’s point of view, but high and poor groundwater zones detected more precisely compared to others in user’s point of view. The methodology, techniques, and results of the current investigation may be useful to evaluate the groundwater potential zone in similar drought-prone regions around the world.

Delineation of Groundwater Potential Using GIS, Hydrogeological, Geophysical and Analytical Hierarchy Process (AHP) Technique in Olorunda-Abaa, Ibadan, Southwest Nigeria

Integration Geographic Information System (GIS), hydrogeological, geoelectrical method involving Vertical Electrical Sounding (VES) technique, coupled with the Multi-Criteria Decision Analysis (MCDA) data mining technique were utilized with the aim to delineate the groundwater potential zones of Olorunda-Abaa area, Ibadan, southwestern Nigeria. Fifty-three (53) Vertical Electrical Sounding (VES) measurements using Schlumberger electrode array, depth to Water Level (DWL) estimation and determination of depth to the bottom of Hand dug wells were carried out across the study area. Multi-criteria Decision Analysis (MCDA) using Analytical Hierarchy Process (AHP) technique was applied to the factors controlling groundwater accumulation in the area. Weights were assigned and subsequently integrated in the ArcGIS environment using Arc Map 10.1 to develop the groundwater potential map of the investigated area. The geoelectric sections developed delineated four subsurface geological units consisting of the topsoil, weathered layer, partly weathered/fractured basement and the fresh bedrock. The VES gave depths to basement bedrock which generally range from 5.6 - 59.4 m. The groundwater conceptual model developed delineated five groundwater potential zones classified as low, medium, high and very high and validated with the thickness of water column obtained from wells over the entire study area. The groundwater potential map generated for the study area show that the medium to very high groundwater potential zones indicates the favourable area where groundwater development is feasible in the study area. This study concludes that the characterization of the groundwater potential zones in the study area can be adopted for future allocation of social amenities, planning, location, development and management of groundwater resources. Keywords: Hydrogeology, Geophysical, Multi-criteria Decision Analysis, Groundwater Potential, Basement Complex, Ibadan. DOI: 10.7176/JEES/11-5-08 Publication date: May 31 st 2021

Modeling Groundwater Potential Zones across Sulaimani Governorate Using Geographic Information System and Multi-influencing Factor Techniques

Groundwater is one of the most important natural resources in the world. The presence of groundwater is the result of interaction of several factors such as: hydrology, geology, climate, ecology, and physiography. The purpose of this paper is to produce groundwater potential zones which are useful in determining the amount of groundwater available in Sulaimani Governorate, North of Iraq. Geographic information system database for six different thematic layers (digital elevation model, rainfall, soil texture, drainage density, slope and land use/land cover) were generated. The study approach involved integration of six layers carried out based on the multiplication of each data raster values with specific weight using weighted overlay analysis method. Raster maps of all the layers assigned a fixed score and weight using multi-influencing factor technique. Based on the resulted map the study area has been divided into four zones that had very high potential zone (1%), high potential zone (14%), moderate zone potential (79%) and low potential zone (6%). About 50% of the high groundwater potential zone were located in Halabja, Rania, and Pshdar districts. Obtained results can be useful in localizing areas of exploration, preventing excessive exploitation of groundwater and planning for suitable sites of artificial groundwater.

Investigation of groundwater potential of the eastern part of Usmanu Danfodiyo University permanent site, Sokoto, using vertical electrical sounding technique.

Geoelectric survey was carried out in the eastern part of Usmanu Danfodiyo University main campus with the aim of determining areas that are suitable for drilling boreholes. Thirty Vertical Electric Soundings were made at different parts of the area using the Schlumberger electrode spread arrangement with maximum half-electrode spacing of 100 m. Qualitative interpretation of the curves suggested thirteen different curve types highlighting that the area is underlain by three to six layers; the top soil predominantly lateritic in composition and occasionally wet, the fresh laterite, shale and limestone layer , the shale, limestone and sandstone layer, clayey sand, coarse sand, shale, limestone and sandstone layer and the fine sandstone and limestone layer. Using the measured current and voltage, apparent resistivity, thickness, depth, hydraulic conductance, transmissivity and protective capacity maps of the aquifers in the area were generated. Based on comparison of groundwater potential zones on these maps, an integrated groundwater potential map of the area was inferred and used to classify the area into low, moderate and high groundwater potential zones. Three zones in the south-central, east-central and extreme northeastern parts were inferred to be suitable for drilling boreholes in the study area.

Groundwater potential as an indicator of water poverty index in drought-prone mid-hill region of Nepal Himalaya

Springs are the primary sources of drinking water for the people living in the mountainous region of Nepal Himalaya, but emerging drought condition exacerbated by climate change has dried up springs thus sparking water crisis in the region. The present study attempts to correlate the groundwater potential (GWP) zones and water poverty index (WPI) in the mid-hill region of Nepal Himalaya. The study was conducted in four drought-prone Village Development Committees (VDCs), namely Bhatauli, Chisapani, Kathjor and Manthali lying at the lower reaches of Tamakoshi Sub-basin in Ramechhap district of Province number 3, Nepal. The in-situ test of spring water revealed that pH, EC, TDS and DO values lie within the concentration limits of Nepal Drinking Water Quality Standards and suitable for drinking or other uses. Groundwater potential zoning was carried out using the eight thematic layers, namely elevation, slope, land use, drainage density, geomorphology, lineament density, rock and soil distribution and precipitation. High groundwater potential has been delineated along the Tamakoshi River while low potential areas lie in the western part of the study area. The model is verified with the field observation as the most springs concentrated in the high and medium groundwater potential zones. The study area has WPI values lower than the national WPI score, suggesting the low availability of water in the area. GWP correlates directly with WPI in the study area suggesting that GWP mapping alone can represent the water availability in the mid-hill region of Nepal Himalaya.

Assessment of groundwater potentiality using geospatial techniques in Purba Bardhaman district, West Bengal

The word water is life, so life on this planet cannot be possible without water. Water is an essential natural resource that is a surface and groundwater device for human society. The purpose of this research is to assess the groundwater potentiality of the Purba Bardhaman district. All data (primary and secondary) are collected from different sources and analyzed in geographic information system (GIS) software to prepare thematic maps. Different geo-environmental factors like as land use and land cover, soil, lithology, rainfall and distance from the river, etc., can impact on groundwater availability directly or indirectly in Purba Bardhaman area. To identify groundwater potential zones, all these factors are composed into GIS software using multi-criteria decision analysis (MCDA) method. The groundwater potential map has been divided into five classes based on their magnitude as very high, high, medium, low and very low groundwater potential zones. It shows that the areas of very low, low, medium, high and very high groundwater potential zones are 21.54%, 35.80%, 26.47%, 10.13%, 6.06%, respectively, of the total area. Finally, validation is carried out using groundwater depth data collected from 44 drilled tube wells which are located in a scattered manner for whole Purba Bardhaman district which indicates a higher similarity with an area under curve value of 86.8%.

Groundwater potential evaluation using geoelectrical and analytical hierarchy process modeling techniques in Akure-Owode, southwestern Nigeria

The complexity and heterogeneity of hydrological conditions in Akure-Owode of southwestern Precambrian basement complex of Nigeria largely control the availability of groundwater supplies in the area. Akure-Owode, being one of the four hydrogeological provinces in Sub-Saharan Africa is worst hit by poor access to continuous supply of groundwater resource throughout the year. Analytical hierarchy process (AHP) modeling technique in conjunction with geo-electric measurements was employed to unravel subsurface complexities and groundwater potential zones in the study area. Geophysical-derived groundwater potential conditioning criteria, namely bedrock relief (B), resistivity (R) and aquifer thickness (T) were synthesized by AHP pairwise comparison weighting and ranking technique to generate groundwater potential indices (GPIs) of the area. Raster-weighted overlay analysis were performed on the GPIs to obtain groundwater potential model (GPM) of the study area. The produced GPM was binned into low, medium and high groundwater potential prediction zones. The performance evaluation of the groundwater potential model using the spatial locations of prolific boreholes and hand-dug wells in the area indicates 80% success rate. Emerging from the vertical electrical sounding curve analysis, weathered (unconfined) and weathered/fractured (unconfined) aquifer types were identified in the area. Hence, the developed groundwater potential map in this study can be harnessed for optimal groundwater resource management of Akure-Owode area.

Application of machine learning techniques in groundwater potential mapping along the west coast of India

ABSTRACT Groundwater potential mapping (GWPM) in the coastal zone is crucial for the planning and development of society and the environment. The current study is aimed to map the groundwater potential zones of Sindhudurg coastal stretch on the west coast of India, using three machine learning models: random forest (RF), boosted regression tree (BRT), and the ensemble of RF and support vector machine (SVM). In order to achieve the objective, 15 groundwater influencing factors including elevation, slope, aspect, slope length (LS), profile curvature, plan curvature, topographical wetness index (TWI), distance from streams, distance from lineaments, lithology, geomorphology, soil, land use, normalized difference vegetation index (NDVI), and rainfall were considered for inter-thematic correlations and overlaid with spring and well occurrences in a spatial database. A total of 165 spring and well locations were identified, which had been divided into two classes: training and validation, at the ratio of 70:30, respectively. The RF, BRT, and RF-SVM ensemble models have been applied to delineate the groundwater potential zones and categorized into five classes, namely very high, high, moderate, low, and very low. RF, BRT, and ensemble model results showed that 33.3%, 35.6%, and 36.8% of the research area had a very high groundwater potential zone. These models were validated with area under the receiver operating characteristics (AUROC) curve. The accuracy of RF (94%) and hybrid model (93.4%) was more efficient than BRT (89.8%) model. In order to further evaluate and validate, four different sites were subsequently chosen, and we obtained similar results, ensuring the validity of the applied models. Additionally, ground-penetrating radar (GPR) technique was applied to predict the groundwater table and validated by measured wells. The mean difference between measured and GPR predicted groundwater table was 14 cm, which reflected the importance of GPR to guide the location of new wells in the study region. The outcomes of the study will help the decision-makers, government agencies, and private sectors for sustainable planning of groundwater in the area. Overall, the present study provides a comprehensive high-precision machine learning and GPR-based groundwater potential mapping.

Assessment of groundwater yield potential in Ekiti East Local Government Area, Southwestern Nigeria

This study presents the categorization of Ekiti East Local Government Area into different groundwater potential zones with a view to reducing incessant boreholes failures and providing sufficient water to meet domestic and agricultural requirements of people in the area. To achieve this objective, 35 locations were sounded using the Schlumberger electrode array. Data obtained from the vertical electrical soundings (VES) were interpreted quantitatively by partial curve matching and 1-D computer iteration to facilitate the selection of an appropriate boreholes location. Thirty-five boreholes were subsequently drilled, and their yields were obtained during pumping test. Synthesizing the geo-electric parameters with the yields of the boreholes, the yield potential map was produced using Surfer 12 software. The VES survey revealed six geo-electric layers including the topsoil (44–1024 Ωm, 0.3–1.7 m), clay (26–494 Ωm, 0.9–30.8 m), laterites (353–1782 Ωm, 0.7–7.7 m), weathered zone–clayey soil (8.9–260 Ωm, 1.4–24.8 m), fractured layer (5.2–929 Ωm, 4.6–11.8 m) and fresh basement with resistivity that ranges from 474 to 77,144 Ωm and undeterminable depth. The bulk of groundwater was localized in the weathered and fractured layers due to availability of pores spaces arising from weathering and fracturing. Long-range in resistivity values especially in the topsoil was due to variation in soil’s composition and differential response to lithification. Two main rock units (migmatite gneiss and fine-grained granite) played major role in the groundwater occurrence of the study area. Thick weathered overburden developed more easily on migmatite gneiss than fine-grained granite. Aquifer yield map classified the study area into low (Eda Ile-Ekiti and Isinbode-Ekiti), medium (Omuo Oke-Ekiti) and high (Ilasa-Ekiti, Ikun/Araromi-Ekiti, Omuo-Ekiti and Kota-Ekiti) yield groundwater potential zones. Low to high groundwater zones cut across migmatite gneiss terrain with about 60% representation of high groundwater potential, indicating the mixed character of the rock. Fine-grained granite had only low groundwater potential coverage. Thus, lithology played a major role in the groundwater occurrence of the study area with terrain covered by fine-grained granite mainly in the low groundwater potential zone. The zones with high yield potential have been deciphered to serve as possible area for the future groundwater development and for choosing the drilling sites.

Delineation of groundwater potential zones in a drought-prone semi-arid region of east India using GIS and analytical hierarchical process techniques

Over-extraction of groundwater has compromised its climatic resilience properties and the arid/semi-arid rural tracts are becoming increasingly vulnerable to the risks of groundwater scarcity. This study has employed a combination of Geographical Information System (GIS) and Analytical Hierarchical Process (AHP) techniques to delineate the Groundwater Potential Zones (GPZs) of the semi-arid Birbhum district in eastern India which suffers from seasonal drought during lean periods. For a reliable evaluation, a large number of thematic layers (N = 12) including geology, geomorphology, Land Use/Land Cover (LULC), fault and lineament density, drainage density, rainfall, soil type, slope, roughness, topographic wetness index, topographic position index and curvature were considered for this assessment. Multicollinearity and consistency checks were performed prior integrating the layers to avoid a non-trivial degree of accuracy in prediction output. The GPZ map was obtained with an accuracy of 80.49% with respect to the observation tube well data. Based on the obtained output, 38.24%, 24.24% and 11.14% of areas of the district classified as moderate, poor, and very poor GPZs, respectively, whereas only 26.38% of the district classified as high to very high GPZs. Cross-validation using the Receiver Operating Characteristic curve revealed a good prediction accuracy of 71.50%. Furthermore, map removal and single parameter sensitivity analysis was also performed which revealed geology, geomorphology, soil types, rainfall, LULC and lineament density as the most influential parameters for the prediction model where exclusion of any thematic layer significantly changes the prediction accuracy and area of each GPZ class. The most convincing GPZs are recorded in some parts of the Mayurakshi and Ajay river basins and certain alluvial aquifer regions. Nonetheless, the study recommends the adaptation of Managed Aquifer Recharge techniques including rainwater harvesting, alternative cropping patterns and irrigation techniques such as sprinklers, drips and micro irrigations to increase the groundwater potential of the water crisis zones.

An Integrated Study to Delineate the Groundwater Potential Zones Using Geospatial Approach of Sidhi Area, Madhya Pradesh

Abstract The surface and groundwater resources are depleting over time, therefore, it becomes essential to monitor and preserve these resources and also to protect their quality. Remote sensing and GIS has become an important tool of hydrological studies in recent times which helps in assessing and mapping of ground-water resources. The remote sensing and GIS approach are well known and widely used techniques to integrate contributing hydrogeological factors namely, geology, geomorphology, lineaments density, drainage density, soil type, slope and land use/ land cover. A study was conducted to delineate the groundwater potential zones in a part of Sidhi area, Madhya Pradesh using remote sensing and GIS techniques. Landsat 8 satellite data and Aster DEM is integrated with toposheets for systematic mapping. All thematic layers were integrated, overlaid and analysed using GIS software. Groundwater potential zone is delineated and to interpret thematic layer, appropriate weights assigned to topographical features for assessing the potential zone. The zones are divided into high, moderate and low groundwater potential zones. The study reveals that 21.36% of the area has high potential, 48.12% moderate and 30.51% low potential zone for groundwater occurrence. The result of this study suggests that the favourable potential zones would prove to be very helpful for better planning and management of groundwater resources in the study area.

Application of Remote Sensing and GIS for Groundwater Recharge Potential Zone Mapping in Upper Betwa Watershed

Abstract Groundwater is unevenly distributed and limited in hard rock terrains. The study has been carried out using remote sensing and GIS to delineate the potential recharge zones of ground-water in upper Betwa watershed, Raisen district, Madhya Pradesh, India. The different thematic layers viz; geology, lineament density, soil, slope, land use/land cover (LU/LC) and drainage density were prepared for assessment of groundwater recharge potential in the area. District Resource Map (DRM) of Geological Survey of India (GSI) 2002 has been used for geological study. SRTM Digital Elevation Model (DEM) was used to obtain the slope. LANDSAT-8 OLI data has been processed for lineament density and LU/LC analysis. Survey of India toposheets were used for drainage density analyses and National Bureau of Soil Survey & Land Use Planning Nagpur (NBSS&LUP) map used for soil study. Weightage has been given to parameters in thematic maps as per the relative influence of each parameter in the groundwater recharge. Rating to each class of parameters was given as per there relative significance in groundwater recharge. Finally, groundwater recharge potential map has been prepared by overlaying all thematic maps in terms of the weighted index overlay (WIO) method. The output map has been further classified into three zones (i) low ground-water potential zone (121.80 km2) (ii) moderate groundwater potential zone (387.78 km2) and (iii) high groundwater potential zone (173.35 km2). The output results were validated by plotting the specific yield data and groundwater level of selected wells in delineated groundwater recharge potential zones using GPS locations. It has been seen that most of the groundwater productive wells functioning in the area is falling in high and moderate groundwater recharge potential zone.

Water Resource Evaluation and Identifying Groundwater Potential Zones in Arid area using Remote Sensing and Geographic Information System

Groundwater resource is the main conventional source of fresh water all over the world. However, recent revelations indicated that the shortage of water resources remains the main challenge for the arid areas. In this regard, identifying groundwater potential zones or areas can help to improve the availability of fresh water and effective management of groundwater in arid areas. This work finds the water resources and identify the groundwater potential zones of arid areas using remote sensing and GIS techniques. The study uses Kingdom of Saudi Arabia (KSA) as one of the most arid area and divides entire KSA into five regions namely northern, central, western, southern and eastern to evaluate and indicate the groundwater prospective zones effectively and clearly. The northern region (Al Jouf, Tabuk, Hail and Al-Qassim), Saq and overlying aquifers play an important role in water supply in Saudi Arabia. About 17.90% of the total area of this region identified as a groundwater potential zone. Based on geomorphological factors, the Wadi catchment areas act as the best appropriate regions for groundwater recharge in the northern area. Regarding the central region (Al-Riyad province), about 1.47% and 4.15% may be categorized as excellent and very good while 12.59%, 74.82% and 6.97% are considered as good, poor and very poor groundwater potential zone. In the western area (Wadi Yalanlan basin), the lower part of the Wadi Yalamlam basin is the most promising zone for groundwater availability containing both high and moderate potential areas. Also, high groundwater potential zones can be found on the northern side of the central dyke region surrounding Abu Helal’s farm. 50.5% and 31% of the southern area (Jazan region) contain excellent and good groundwater potential areas while 16% and 2.5% of the regions showed average low groundwater potential zones. The eastern region had characteristics of extreme arid and desert environments. Based on the features, the area did not contain any groundwater potential zone. The current evaluation of groundwater potential areas in Saudi Arabia can serve as a significant tool for efficient groundwater resource management.

Groundwater potential evaluation in the basement complex terrain of Ekiti East Local Government Area, Southwestern Nigeria

Availability of groundwater often constitutes a problem in basement terrain because of its erratic occurrence. Incessant failures of boreholes have been reported in Ekiti East Local Government Area (EELGA), Southwestern Nigeria warranting evaluating its groundwater potential using a multi-criteria model that involved geology, resistivity and thickness (GRT) model of the aquifers across the study area. Thirty-five (35) locations were occupied using vertical electrical sounding (VES) technique employing the Schlumberger electrode array. The VES data were interpreted quantitatively by partial curve matching and 1-D computer iteration to facilitate siting of appropriate boreholes locations. The geophysical survey revealed twelve (12) types of resistivity curve: KH ($$\rho 1 \rho 3 \rho 3>\rho 4 \rho 3>\rho 4>\rho 5)$$, QH ($$\rho 1>\rho 2>\rho 3 \rho 3>\rho 4)$$, HKQ ($$\rho 1>\rho 2 \rho 4>\rho 5)$$, AK (ρ1 ρ4), HA ($$\rho 1>\rho 2 \rho 3 \rho 2 \rho 2>\rho 3 \rho 2 \rho 4<\rho 5)$$. The four-layer curve types observed within the area accounted for 57% of the curve types, while the five-layer types were 43%. The maps of aquifer layer resistivity and aquifer layer thickness were generated and synthesized with the geology of the study area in producing the GRT model groundwater potential map. The groundwater potential map revealed the northern part of the study area as an area with high groundwater potential, while the southern part was characterized as low groundwater potential terrain. EELGA is categorized into low, medium and high groundwater potential zones with the northern part more favorable for siting of boreholes. The groundwater potential map will serve as an exploration guide in addition to its usefulness in groundwater sustainability development.