Good Groundwater Potential Zones Research Articles

Remote sensing, GIS, and analytic hierarchy process-based delineation and sustainable management of potential groundwater zones: a case study of Jhargram district, West Bengal, India.

The present investigation delineates groundwater potential zones (GPZ) in the Jhargram district through an integrated approach employing analytical hierarchical process (AHP), remote sensing, and geographical information systems (GIS). Twelve parameters were utilized for GPZ analysis based on the Groundwater Potential Index, subsequent to multicollinearity testing. Classification of GPZ yielded five distinct categories: very poor, poor, moderate, good, and very good. Validation through receiver operating characteristics (ROC) and cross-validation with borewell yield data affirmed prediction accuracies of 78.4% and 84%, respectively. Spatial distribution analysis revealed that 30.39%, 30.86%, and 13.19% of the surveyed area fell within the poor, moderate, and good potentiality zones, respectively, whereas 15.86% and 9.69% were categorized as very poor and very good GPZs. Sensitivity analysis highlighted the significance of geology, elevation, geomorphology, slope, and lineament density as influencing parameters; elimination of any single parameter engendered significant alterations in the GPZ classification. The investigation culminated in the formulation of a block-wise sustainable groundwater management blueprint designed to inform policy initiatives.

Multi-criteria approach to assess groundwater potential: a case study of Baringo County, Kenya

Abstract In this study, the groundwater potential zones in Baringo County (Kenya) were identified using an integrated approach of Remote Sensing-Geographic Information System (RS-GIS) and Analytical Hierarchy Process (AHP) techniques, and thematic layers of rainfall, slope, lithology, soil type, land use, drainage density and lineament density. The data were validated using borehole yield and fluoride data obtained from boreholes in the area. Using RS-GIS-based methods to identify potential groundwater zones is more convenient and less expensive compared with the conventional methods. Rainfall, lithology, soils and land use/land cover were found to be the most significant factors influencing groundwater with weighted values of 31, 24, 18 and 10% respectively. The very good, good and poor potential zones covered 0.39, 65.33 and 34.27% area coverage of the study area respectively. Low yield boreholes were found in the poor groundwater potential zones and vice versa. Moderate yield boreholes were found in the good groundwater potential zone. The majority of the boreholes with acceptable fluoride concentration was found in the good groundwater potential zones, while those with high fluoride concentration levels were found in the poor groundwater potential zone. Generally, from this study, it can be concluded that remote sensing and GIS in conjunction with AHP are important tools in monitoring and evaluating groundwater resource potential areas.

Identification of groundwater potential zone using analytical hierarchical process (AHP) and multi-criteria decision analysis (MCDA) for Bhavani river basin, Tamil Nadu, southern India

The present study aimed to identify groundwater potential zones was involving the collection of both spatial and non-spatial datasets for water management practice. The Bhavani river basin groundwater is the major source for agriculture, domestic, industry, etc. The basin area is divided into lower and upper sub-basins of an area of 4207 km2. To delineate the Groundwater Potential Zone (GWPZ) ten thematic layers (geology, geomorphology, land use land cover, drainage and lineament density, slope, elevation, soil texture, rainfall, groundwater) were prepared using Arc GIS 10.3 software. The Analytical Hierarchical Process (AHP) based Multi-Criteria Decision Analysis (MCDA) was used to calculate the weightage value for each parameter. For parameter validation consistency index and consistency ratio were used. The identified groundwater potential zone was categorized into five classes based on the groundwater potential availability, as very high (1599 km2), high (1430 km2), moderate (547 km2), low (421 km2), and very low (210 km2). In the middle portion of the basin, 38% of the area falls under very good GWPZ and is followed by high (34%), moderate (13%), low (10%), and very low (5%) identified the different location of the basin. Further, GWPZ were classified based on firka and compared to the Public Work Department (PWD) 2011 and 2020 reports. From the report, 22 firkas are over-exploited from 2011 to 2020. In the present study GIS coupled with the AHP model gives accurate groundwater recharge zones. It's more helpful for drought risk assessment and planning recharge structures for agriculture engineers and government agencies.

Delineation of groundwater potential zones in lower Rihand River Basin, India using geospatial techniques and AHP

In the present study, an attempt is made to delineate groundwater potential zones in Lower Rihand River Basin using remote sensing, GIS, and Analytical Hierarchical Process (AHP). Multiple data, viz. lithology, lineament density, geomorphology, slope, soil, rainfall, drainage density, relief, landuse/landcover were considered for delineating the groundwater potential zones. All nine thematic layers were prepared using remote sensing data on GIS platform. After that, weights were assigned to different layers and the features within them using a pairwise comparison matrix through the Analytical Hierarchical Process. The weights obtained were tested for their consistency using the consistency index and consistency ratio. A final weighted map was then obtained by multiplying each thematic layer’s weights with the weights of features within them and adding them. Based on this final weighted layer, the basin was categorized into very poor, poor, moderate, good, very good groundwater potential zones. The maximum area (49.22%) is under poor groundwater potential zone followed by moderate zone (26.17%), very poor (12.53%), good (11.77%), very good (0.31%). Results obtained have been validated using pre-monsoon and post-monsoon 10 years average water depth and seasonal fluctuation of various observation wells. Sensitivity analysis using map removal method is performed to assess the most influential parameters, geology, geomorphology, lineament density are the most influential. Overall results prove the efficacy of the use of geospatial technology in combination with AHP in the delineation of underground water potential zones.

Determination of groundwater potential zones using Geographical Information Systems (GIS) and Analytic Hierarchy Process (AHP) between Edirne-Kalkansogut (northwestern Turkey)

Groundwater is one of the most important resources when it comes to satisfying the freshwater needs of a region. In recent years, due to the growing climate change threat to water supplies, the importance of groundwater resources has increased. The main aim of this study is to determine groundwater potential zones using Geographical Information Systems (GIS) and Analytic Hierarchy Process (AHP) techniques in the area of Edirne-Kalkansogut, Northwestern Turkey. Several environmental parameters (lithology, fault density, geomorphology, soil, land use and land cover, drainage density, lineament density, precipitation, and slope) were analyzed to determine groundwater potential zones. The weighting of the parameters was conducted using the AHP technique, overlay analysis was carried out on the GIS platform. According to obtained results; 14% of the study area exhibits poor groundwater potential and 47% of the study area has moderate groundwater potential. Good groundwater potential zones and very good groundwater potential zones constitute 31% and 8% of the study area respectively. The groundwater potential increasing gradually from the northeast to southwest. Tundzha Rivers' alluvial flood plain shows very good groundwater potential and most of The Strandzha Massif have poor to moderate groundwater potential. Examination of groundwater characteristics such as groundwater levels, groundwater flow directions, springs and wells' distribution characteristics, and well discharge data verified the results. Findings have great potential to increase the success of water management policies, efficient use of natural resources, physical planning, and sustainable groundwater development between Edirne-Kalkansogut, especially in the brink of climate changes’ unfavorable threats to human life. The methods of this study can be applied anywhere else in the world. The results of this study have applications to the further studies dealing with sustainable groundwater, basin management, agriculture, and climate change-groundwater relationship.

Groundwater exploration in hard rock terrains of East Godavari district, Andhra Pradesh, India using AHP and WIO analyses together with geoelectrical surveys

<abstract> The need for groundwater exploration in India has been increasing enormously, due to the non-judicial use of available water resources. The present study area is located between longitudes from 81°52′20.293′′ to 82°29′32.058′′ E and latitudes from 17°01′6.71′′ to 17°38′ 12.906′′ N in the Eastern Ghats mobile belt region of East Godavari district. The study area is characterized by a wide range of geological settings and high and irregular topographic features. The area is identified by Government as highly backward and Tribal people dwell here. For exploring good aquifer in the study area, the information of ten parameters together with geoelectrical resistivity data has been collected. Analytical Hierarchy Process (AHP) is used as the decision-making technique which uses the weights of different thematic layers (parameters) favorable for groundwater recharge, storage and location. Various thematic layers (parameters) of geology, geomorphology, soil, slope, lineament density, drainage density, groundwater level, Land use/Land cover, rainfall and coefficient of electrical anisotropy were considered in this analysis. A comprehensive groundwater prospect map has been prepared and validated with aquifer thickness map derived from the analysis of geoelectrical data. The entire study area has been classified into different potential zones of good, moderate and poor for groundwater exploration. The good groundwater potential zone is covering an area of 750.91 sqkm (28.4%) with aquifer thickness varying in the range 40–140 m, moderate potential zone encompasses 46.1% of the study area with an areal extent of 1220.33 sqkm and aquifer thickness is about 20–40 m. The remaining area of 24.5% is poor aquifer zone with thickness less than 20 m. </abstract>

Identification of groundwater potential zones using geospatial approach in Sivagangai district, South India

The study area, Sivagangai district is considered as one of the drought prone districts of south India. Hence, there is a need of study to identify the groundwater potential zones in this region. Firstly, thematic layers (geomorphology, geology, drainage, lineament, slope, and soil) were produced using satellite images in Arc GIS platform. Analytical hierarchy processes (AHP) was done to compute the weightage for each layer with respect to the relative importance of groundwater potential index. All the thematic layers were reclassified according to their water-bearing properties with the weightages derived by AHP. The consistency of derived weightage is evaluated as 0.082 which is below the standard consistency ratio of 0.1 and is consistent. Through overlying analysis of all thematic layers, a groundwater potential map was produced using geographic information system (GIS). Four major groundwater potential zones were identified as very good, good, moderate, and poor. Majority of the study area were classified as moderate (38.2%) and good (30.8%) groundwater potential zones. Groundwater level map was used to validate the groundwater potential zone. The groundwater potential map can be used to identify the appropriate locations for artificial recharge. Artificial recharging structures such as percolation ponds, recharge shaft, and farm ponds have to be implemented to improve the water level in the region. The outcome of this study strengthens the knowledge of geospatial analysis for groundwater vulnerability and also allows policymakers in this drought-prone area to sustainably manage water supplies.

Fuzzy logic techniques and GIS-based delineation of groundwater potential zones: a case study of Anger river basin, Ethiopia

As the demand for drinking water worldwide increases for human consumption, agriculture and industrial uses, the need to assess the potential of groundwater and aquifer productivity also increases. Access to water supply in Ethiopia is among the lowest in the world. In some regions of Ethiopia, people make three–five round trips to get dirty water from the river per day. Each roundtrip takes 2–3 h and water is carried in around “50-lb jerrycans” according to an article by Tina Rosenberg for National Geographic. Therefore, delineation of groundwater potential in Ethiopia is a need of an hour. The objective of this study is to develop a spatial model using a fuzzy logic approach integrated with geographic information system (GIS) domain to demarcate the groundwater potential zones (GPZ) of Anger river basin Ethiopia. Nine thematic layers such as geology, slope gradient, drainage density, Roughness, profile curvature, plan curvature, wetness index, soil texture, soil type, and land use were prepared, analyzed and studied for GPZ delineation. The groundwater potential zone map thus obtained was categorized into five classes: very good, good, moderate, low and very low. The study reveals that about 28.44% of the Anger river basin is covered under very good GPZ. Very poor, poor, moderate and good GPZ are observed in 8.06%, 15.47%, 21.36%, and 26.67%, respectively. The area under very poor and poor potential zones is recorded only in very limited areas in the basin. This study proved the efficiency of the fuzzy logic approach coupled with GIS an efficient model for demarcation of GPZ and can be applied at a continental scale.

Can Groundwater Scenarios Be Predicted from Future Regional Climatic Input Variables?

Conjunctive use of water is an integral part of water resources management. Future groundwater scenarios will dictate the water management policies. The present research focuses on future groundwater scenario generation based on regional scale CMIP5 data. The future scenarios for the years 2030, 2050 and 2080 were generated in terms of the groundwater potential zones (GWPZs) with seven futuristic parameters [land use and land cover, maximum temperature, minimum temperature, rainfall, groundwater recharge, groundwater table and evapotranspiration (ET)]. The Dyna-CLUE and MIROC5 were used for generation of the future change in climate and land use/land cover scenarios. The Soil and Water Assessment Tool (SWAT) was utilized for the recharge and ET estimation. Future groundwater heads were calculated by using the Modular Three-Dimensional Finite-Difference Groundwater Flow (MODFLOW). Bias corrected rainfall and temperature data of Representative Concentration Pathways (RCP 4.5) were utilized. Total twelve water quality parameters (pH, Cl−, Mg2+, F−, Na+, EC, TH, HCO3−, K+, Ca2+, SO42− and PO42−) were used for groundwater quality zone (GWQZ) mapping. These GWPZ and GWQZ were divided into three (poor potential, moderate potential, and good potential) and four zones (good quality, moderate quality, poor quality and above permissible limit) respectively. The lower part of the basin was identified as poor GWPZ (35.76% for 2030) and GWQZ due to an increase in urban areas. However, the middle and upstream portion covers good, moderate zones. Field-based soil moisture and groundwater level monitoring data were utilized for validation purposes. It was observed that groundwater level < 5 m bgl corresponds to good GWPZ. It was also observed that recharge and pH were the crucial parameters for good GWPZ (+11.83%) and GWQZ (−21.31%) according to sensitivity analysis.

Evaluation of groundwater potential zones using integrated geophysical approach in Obun-Ewi, Ondo East local government, Southwestern Nigeria

Obun-Ewi area is underlain by the Precambrian Basement Complex rocks of Southwestern Nigeria. The area suffers from a shortage of freshwater and the main source of water is rainwater. Groundwater provides an alternative solution to face the gap between water demand and available water in this area. Groundwater study involving the application of a very low frequency electromagnetic (VLF-EM) survey and vertical electrical sounding (VES) was carried out in parts of Obun-Ewi area Ondo State, Nigeria to evaluate the groundwater potential of the study area. ABEM WADI equipment was used to establish six (6) VLF-EM traverses with a station interval of 10 m. The inversion of the real component data of VLF-EM into 2D pseudo-sections was generated using Karous-Hjelt software. Linear features assumed to be minor fractures/conductors inferred from the filtered real pseudo-sections helped in choosing twenty-three (23) vertical electrical sounding points that were further probed using DDR-3 resistivity equipment. The Schlumberger electrode configuration was employed with half-current electrode separation (AB/2) ranging from 1 to 100 m. The partial curve matching technique was used to interpret the VES data quantitatively. The geoelectric parameters (depths and resistivities) were used to produce the geoelectric sections, isoresistivity map, isopach maps of the weathered layer and overburden, longitudinal unit conductance map and bedrock relief map of Obun-Ewi, Ondo town. The results obtained from the geoelectric sections revealed three subsurface geologic layers, namely: the topsoil, weathered layer (comprises of clay/sandy clay and laterite), and fractured basement/fresh bedrock. The topsoil resistivity varied from 56 to 1222 Ωm, and depth ranged from 0.5 to 1.8 m. The weathered layer resistivity values ranged from 16 to 1168 Ωm; while the thickness varied from 0.7 to 6.2 m. The overburden thickness varied between 1.6 and 7.2 m. The delineated weathered and fractured basement columns constituted the aquifer units. The composite groundwater potential map generated demarcated the study area into good, moderate and poor groundwater potential zones. The groundwater potential map revealed that about 69.6% of the study area fell within the poor groundwater potential rating, about 21.7% constituted the moderate groundwater potential rating while the remaining 8.7% constituted high groundwater potential rating. The study concluded that the groundwater potential of Obun-Ewi, Ondo town is generally poor, with areas around central South (around VES 9) and far Northern part of the study area (around VES 21) has good groundwater potential, suitable for siting boreholes.

Assessment of groundwater potential zones using multi-criteria evaluation technique of Paisuni River Basin from the combined state of Uttar Pradesh and Madhya Pradesh, India

The Paisuni River Basin forms the combined state of Uttar Pradesh (UP), and Madhya Pradesh (MP), India. It is an agricultural-dominated area in the flood plains where groundwater plays a crucial role for agricultural purpose. In the present study, an assessment of groundwater potential (GWP) zones is carried out using multi-criteria evaluation techniques. Different thematic maps such as landuse/landcover, geomorphology, lithology, soil, slope, lineament, drainage and rainfall maps were considered for the delineation of potential zones. The present work was carried out to delineate the GWP for the two different states as well as for the various villages of UP and MP. Approximately, 44% and 13% for good potential, 32% and 18% for moderate potential and 6% and 14% for the low potential of groundwater are delineated from the states of UP and MP. The village wise shows that 1% good potential is in the state of MP; however, 99% shows good potential for the villages of UP. Rainfall data also indicates that UP receives more annual rainfall than MP. The majority of the area in UP suggests good groundwater potential zones. Thus, the results will be helpful in better planning and management of groundwater resources in the Paisuni River Basin as well as rainwater harvesting in different villages where there is a poor potential of groundwater to meet the future need of water in these villages.

Identification of Groundwater Potential Zones Using Analytical Hierarchy Process (AHP) and GIS-Remote Sensing Integration, the Case of Golina River Basin, Northern Ethiopia

Groundwater is the main source of water both for domestic and irrigation purposes in the study area, Golina basin. The Golina basin is located in the North Wollo Administration, Amhara regional state, Northern Ethiopia. The study area has a surface area of 916.77 km 2 and is a semi-arid environment with an annual mean precipitation of 913 mm/year. Because of its presumed groundwater potential, the area has recently received significant attention from the regional and federal governments as well as investors. As a result, 81wells have been drilled for groundwater extraction mainly for irrigation purposes. About 182 springs and hand-dug wells have been developed for domestic purposes. However, little has been done to know the overall groundwater potential, the groundwater potential zonation and the sustainability of the current and planned groundwater extraction in the basin. Thus, the main objective of this work is to delineate groundwater potential zones of the area using an integrated method of AHP, GIS, and Remote sensing. A total of 10 thematic layers are used for the groundwater potential zone assessment. Based on the AHP method, the priority of the thematic layers with their weight are as follows: geology (0.22), geomorphologic landform (0.22), lineament density (0.17), slope (0.12), drainage density (0.09), soil (0.07), land use land cover (0.04), precipitation (0.04), normalized difference vegetation index (NDVI) (0.02) and topographic wetness index (TWI) (0.02). The groundwater potential zones of the area are computed using raster calculator in spatial analyst tool in GIS software and divided into five classes as very poor, poor, moderate, good and very good with area coverage of 93 km 2 (10%), 265km 2 (29%), 175 km 2 (19%), 221 km 2 (24%) and 162 km 2 (18%) of the total area, respectively. The result is validated using the existing spring, hand-dug wells and borehole yields. Accordingly, the high yield boreholes are drilled and concentrated in very good groundwater potential zones whereas the low yield springs are developed in the very poor. Out of 263 water points 74, 72, 48, 59 and 10 water points are located in very good, good, moderated, poor and very poor groundwater potential zones, respectively. Mainly the very good groundwater potential fall in the alluvial deposit, plain and valley landforms, very low slope (flat), high lineament density, low drainage density, coarse soil textures, and water body and cultivated lands with high precipitation, NDVI and TWI. The result of this study can be used for the planning of new groundwater-based projects and the expansion of the existing irrigation project in the basin. DOI: https://doi.org/10.23953/cloud.ijarsg.460

Groundwater potential mapping using geospatial techniques: a case study of Dhungeta-Ramis sub-basin, Ethiopia

ABSTRACT The objective of this paper is to exploit the potential application of weighted index overlay analysis for assessing groundwater potential mapping at Dhungeta-Ramis sub-basin, Wabi Shebele basin, Ethiopia using remote sensing and geographic information system (GIS) technique. For this purpose, seven groundwater occurrences and movement controlling factors, including, lithology, slope, land use land cover (LULC), rainfall, lineaments, soil, and drainage density were mapped. Then, weight was assigned to thematic maps, and the groundwater prospective of the sub-basin is qualitatively classified into five classes, namely, very good, good, moderate, poor, and very poor which account for 2.22%, 26.93%, 56.74%, 13.84%, and 0.26% landscape, respectively. The cross-validation of the resultant model was carefully carried out using spring, hand-dug, and deep well data. The result reveals that 89% of springs were overlaying good and/or very good groundwater potential zones and 58% of deep well shows the same scenario, whereas 42% of deep well overlays moderate zone. As a result, the map generated using this platform could be used as a preliminary reference in selecting suitable sites for groundwater resource exploitation.

Groundwater potential assessment using GIS and remote sensing: A case study of Guna tana landscape, upper blue Nile Basin, Ethiopia

Study regionGuna Tana Landscape, Upper Blue Nile Basin, Ethiopia. Study focusThis paper aimed to delineate the groundwater potential zones using GIS and remote sensing. Multi-Criteria Decision Analysis (MCDA) technique is used to develop the groundwater potential prospect zones by integrating different groundwater contributing thematic layers. The thematic layers of land cover, drainage density, lineament density, soil, geology, slope, and geomorphology were prepared and used for groundwater potential map development by assigning weights to each thematic layer and features. The weights of each thematic layer were assigned and normalized based on their characteristic and relationship with groundwater recharge. Finally, the thematic maps were integrated by a weighted sum overlay analysis tool to develop groundwater prospect zones. New hydrological insights for the regionIt was found that the downstream parts of the Landscape showed excellent groundwater potential covering about 833.49 km2 area with a flat and lacustrine sediment characteristic. About 469.12 km2 of the landscape showed very good groundwater potential zone. Northern, northeastern and southeastern parts of the area presented very poor groundwater prospect covering about 553.68 km2 area. The groundwater potential map was validated using the existing pumping wells and it indicated a good prediction accuracy of 70.5%. Thus, the potential zones identified in the study area by the MCDA technique are reliable.

Investigation of groundwater resources in highland Ethiopia using a geospatial technology

Because of the rapid growth of human population combined with a decline in quality and quantity of surface water, the demand for groundwater has been rapidly increasing in Ethiopia. It is also highly anticipated that climate change-induced variations in hydrometeorological parameters will make groundwater more indispensable and scare resource in Ethiopia at some point. It is, therefore, essential to well understand the characteristics and potential areas of groundwater for proper management and use. In this study, an attempt has been made to identify groundwater potential zones in the Rib watershed, north-western highland Ethiopia. The thematic layers of the main factors that control the occurrence and movement of groundwater in hard rock regions were ranked, weighted and aggregated in a linear combination equation in ArcGIS Raster Calculator to generate the groundwater potential zone map. The generated map was then classified into five categories which represent very poor to very good groundwater potential zones. It was found that the downstream areas comprising gentle slope, alluvial deposits, and floodplains have very good groundwater potential zone which cover approximately 294 km2 (14.87% of the watershed). The upstream areas in the eastern and south-eastern parts of the watershed fall into low (either poor or very poor) groundwater potential zone due to high runoff and low infiltration. The generated groundwater potential zone map was finally validated using borehole points, which showed a good correlation. The results of this study will be helpful for better planning and management of local groundwater resources.

Application of geospatial techniques in delineating groundwater potential zones: a case study from South India

Exploring the status of groundwater in terms of its potentiality is of serious concern, owing to its vital use for domestic, agricultural, and industrial requirements all over the world. The aim of this paper is to assess the groundwater potentiality in Rasipuram taluk, Tamil Nadu, India by combining the geospatial techniques like geographical information system (GIS) and remote sensing (RS). The groundwater potential zones are delineated by integrating the factors such as geology, drainage density, geomorphology, lineament density, land use/land cover, and slope. The layer weight for six factors governing groundwater recharge potential and class weight for each factor are assigned based on their characteristics and relative importance with groundwater. A groundwater potential zonation map is obtained after integration through weighted index overlay analysis (WIOA) in GIS domain and is divided into four categories, viz., good, moderate, poor, and very poor zones. The study depicts 26%, 17%, and 27% of the total study area comes under moderate, poor, and very poor groundwater potential zones, respectively, while good groundwater potential zone cover 30% of the total study area. The results indicate that the most convincing groundwater potential zones are located in the western region of the study area which has relatively plain topography.

Hydrogeophysical Investigation for Groundwater Resources from Electrical Resistivity Tomography and Self-Potential Data in the Méiganga Area, Adamawa, Cameroon

Exploration and production of groundwater, a vital and precious resource, is a challenging task in hard rock, which exhibits inherent heterogeneity. A geophysical survey was conducted in Méiganga, Mbéré department, in the Adamawa region, Cameroon. High-resolution electrical resistivity tomography (ERT) and self-potential (SP) dataset were collected in a gneissic terrain to solve the groundwater problem as people are facing acute shortage of drinking water in the study area. The analysis and interpretations based on resistivity models revealed substantial resistivity contrast between the altered gneiss that might contain water and massive gneiss and delineated five deeper groundwater prospects zones located at Yelwa, Ngoa-Ekélé, Sabongari, Ngassiri, and Gbakoungué, respectively. Nevertheless shallow groundwater zones (&lt;13 m) are located in the northern part of the study area at high elevation while best prospect and productive groundwater zones lying between 20 and 25 m depth are at low elevation in the southern part. On the other hand, analysis of SP negative peaks along with groundwater head and groundwater vector maps revealed areas of recharge and discharge across the study area. The discharge areas serve as groundwater collection center and are good groundwater potential zones. In addition these maps revealed that groundwater flow pattern shows inward flow from the flanks to center and south central parts of the study area.

Delineation of groundwater potential zones of Atrai–Sib river basin in north-west Bangladesh using remote sensing and GIS techniques

Present research work is carried out in the Atrai–Sib river basin in the drought-prone but agro-based Barind area in the north-west of Bangladesh to delineate the groundwater potential zones using integrated approach of remote sensing (RS) and geographic information system (GIS)-based multi-criteria evaluation. Decreasing trend in rainfall along with increasing population in this drought-prone area calls for a sustainable development of the groundwater resource. The river basin possesses dendritic drainage pattern and major portion of runoff water allows more infiltration to recharge the groundwater and is, therefore, a potential for groundwater occurrence. The gentle to flat river basin is of ‘excellent’ category for groundwater management because of favorable infiltration to maximum time of runoff percolation. Here, seven different thematic layers such as, geomorphology, drainage density, rainfall, lithology, lineament density, slope and land use/ land cover (LULC) are integrated in GIS environment to study groundwater potentiality. Corresponding normalized rates for the classes in a layer and weights for the thematic layers are computed using Saaty’s Analytical Hierarchy Process (AHP), and then aggregated thematic map is prepared using a weighted linear combination (WLC) method. Map-removal and single-parameter sensitivity analysis are used to examine the effects of removing any thematic layer on the groundwater potential zones and to compute effective weight, respectively. About 226 km2 (6% of the study area) is designated as very good groundwater potential zone, whereas that of good, moderate, very poor and poor groundwater potential zones cover 407 km2 (11%), 720 km2 (19%), 997 km2 (26%) and 1418 km2 (38%), respectively. Sensitivity analysis shows that the groundwater potential zonation in the study area is most sensitive to lineament density (mean variation index 2.66), which is the most effective thematic layer in the groundwater potentiality zone (mean effective weight of 27.13%) and supports the need for future river basin development and management. This study can help to identify the groundwater potential zones of this drought-prone area that will lead towards the planning of the integrated water resources management.

Studies of Environmental Hazards and Groundwater Potential Zones of Arkavathi Catchment of Greater Bangalore Area, Karnataka, South India

Water, air and soil are three important natural resources in which water is the most important natural resource which is polluted qualitatively. Remote sensing and geographical information system data is a powerful and effective tool for identifying pollution and potential zones of groundwater. Peenya industrial wastewater and domestic sewage flows in Arkavathi river catchment in the Greater Bangalore area due to which water gets polluted and enters into the groundwater aquifers through geological structures. The main objective of the study is to know the role of geological structures as avenues for ground water contamination and the mechanisms of aquifer pollutions and identification of the potential zones for ground water in the Arkavathi river catchment using remote sensing, geographical information system and geophysical techniques. Monsoon, pre-monsoon and post monsoon water samples were collected and analysed in the laboratory as per the Bureau of Indian standards parameters (BIS 10500-1991). Results indicated that many water quality parameters were above the permissible limit. The thematic maps such as geology, geomorphology, lineaments, slope, soil maps and land use/land cover etc. were prepared using the satellite imagery (IRS P6 LISS IV MX) and Survey of India Topo sheets. Electrical resistivity survey was carried out at 11 locations in the Arkavathi river catchment to find out the thickness of the underground layers and to know the depth range of the fractured zone, depth to basement and lineaments which plays a significant role in ground water pollution and potentiality particularly in hard rocks. The potential zones were identified mainly using the thematic maps, secondary or collateral data and correlating with vertical electrical soundings (VES) data. The study has revealed that the geological structures are the main carrier of the pollutant particles. The study also shows that Arkavathi river catchment is more polluted due to higher concentrations of lineaments, weathered zone and shear zones identified by VES, remote sensing and geographical information system data which forms the avenues for circulation and infiltration of pollutants into the aquifer. Good ground water potential zones are confined along lineaments, valley, valley fill and water bodies (19.54 % of the total study area) and Pediplain shallow weathered, pediplain eroded, plains and mounds form a moderate potential zone ( 74.51% of the total study area). Other geomorphic units like pediments form a moderate to poor (3.72% of the total study area), pediment inselberg complex form a poor prospect zone (1.71% of the total study area) and poor to nil (0.51%of the total study area) occupies a small portion of study area composed mainly of Residual hills. Keywords: Water quality, Geological structures, Geomorphology, Satellite imagery, Groundwater Potential Zone.

Geospatial decipherment of groundwater potential of Kattankolathur block of Tamil Nadu using MCDM techniques

The international hydrological community is addressing problem of scarcity of water and judicial and optimum groundwater development and sustainable management by the available knowledge and tool equipped. For the present study, an attempt has been made in understanding, the importance of different hydrogeological parameters, which control the groundwater potential of an area and finally characterization of the area into different groundwater potential zones. The study area is Kattankolathur block of Kanchipuram district, Tamil Nadu, Southern India, which extends over a geographical area of 378.536 sq. km. Different temporal satellite images and collateral data are used to prepare number of thematics for the analysis. Further these thematics by giving suitable weightage and assigning respective ranks using Multi Criteria Decision Making (MCDM) technique depending upon their control over groundwater potential are overlaid by using weighted overlay analysis tool available with ArcGIS and the final groundwater potential map has been prepared. By performing this multi criteria analysis, the area is categorized into different classes’ viz., Very poor, poor, moderate, good and very good groundwater potential zones. The study shows 101.448 sq. km and 152.172 sq. km of very poor to poor groundwater potential, whereas 83.277 sq. km of the area is coming under moderate potential zone. The rest area, 27.76 sq. km. is coming under good and only 13.879 sq. km found to be under very good groundwater potential zone. Different sample locations are been considered over the area and the water level has been collected from different control wells for pre and post monsoon periods and validated. Ares namely Palur Villampakkam, Attur, Timmenpuram and Chengalpattu Shows high groundwater potential and less populated. In the contrast areas like Paranur, Singaperumal Koil, Marammalai Nagar, Potheri, Guduvanchery, and Vandalur are highly populated and industrialized and are coming under moderate to very poor potential zones.