Groundwater Potential Index Map Research Articles

Evaluation of Groundwater Potential Using Aquifer Characteristics in Urambo District, Tabora Region, Tanzania

In developing countries like Tanzania, groundwater studies are essential for water resource planning, development, and management. Limited hydrogeological information on groundwater occurrence, availability, and distribution in Urambo District is termed a key factor that hinders groundwater development. This research was aimed at the evaluation of groundwater potential zones in a granitic gneiss aquifer in Urambo District by integrating six indicators (transmissivity, specific capacity, static water level, yield, total dissolved solids, and geology) that were developed and applied in the study area. The indicators were further combined, and a groundwater potential index map (GWPIM) was prepared using relative weights derived from the analytical hierarchy process (AHP). The results show that 67% and 27% of the study area are categorized as moderate and high groundwater potential zones, respectively. Groundwater is controlled by both Quaternary sediments (sands and gravels) and weathered to fractured granitic gneiss. Quaternary sediments host the major shallow aquifers (<35 m) with relatively high transmissivity, specific capacity, and yield (1.5 m2/day, 16.36 m2/day, and 108 m3/day, respectively). Granitic gneiss is not strongly fractured/weathered and forms an aquifer with a relatively low yield of about 10.08 m3/day. The findings were validated using three boreholes, and the results are consistent with the developed GWPIM. Such findings are of great importance in groundwater development as the techniques applied can be extended to other areas in Tanzania as well as other countries that experience similar geological environments.

Groundwater potential zone in Bachok District, Malaysia: Application of Remote Sensing and GIS Technique

The research aimed to identify probable groundwater zones by integrating GIS, remote sensing, and AHP techniques. Given the rising demand for water resources due to population growth and economic expansion, groundwater resources are vital. The paper presented a comprehensive approach to achieving this goal. Integrating geographic information systems with analytic hierarchy processes is demonstrated to obtain precise decision-making information through transforming geographical data and weightage ranking. The present study has identified seven principal criteria controlling parameters significantly impacting groundwater occurrence. These criteria have been derived from analysing satellite imagery, existing maps, and data sources. The abovementioned variables encompass drainage density, elevation, annual precipitation, slope gradient, land use and land cover. The overlay-weighted sum method maps the potential groundwater zones in the research area by incorporating all thematic criteria. The groundwater potential index map has identified various zones with differing levels of groundwater potential, ranging from very low (1.61%, low (1.81%), moderate (2.66%), high (22.59%) and very high (71.33%). Ultimately, the mean groundwater level information obtained from five wells in the study area is employed to authenticate the map depicting the potential groundwater zones. This research discusses the significant implications that need to be considered for sustainable groundwater exploration in the area.

Aquifer evaluation in parts of north-central Nigeria from geo-electrical derived parameters

In order to reduce the level of risk associated with borehole drilling, it is important to have detailed knowledge about the aquifer distribution. In a view to generating groundwater potential model of Lokoja and its environs, the detailed subsurface characterization was carried out using a GIS-based multi-criteria decision analysis approach. One hundred and twenty-four vertical electrical sounding (VES) data points were covered within the study area using the Schlumberger array of electrical resistivity surveys. Hydrogeological investigation of one hundred and twenty-four existing boreholes within the vicinity of the sounded VES points was carried out by measuring in situ parameters of each borehole such as borehole depth, elevation, static water level and borehole yield. A Multi-Criteria Decision Analysis-Analytical Hierarchy Process (MCDA)-AHP-based was carried out by estimating the probabilistic ratings for the classes of parameters used for modeling groundwater potential. Four groundwater potential influencing factors, namely coefficient of anisotropy, transverse resistance, aquifer resistivity and aquifer thickness, were classified and rated. The output of the multi-criteria decision analysis was processed in the GIS environment to produce a groundwater potential index map. The obtained model was validated by comparing it with in situ borehole yield data to determine the accuracy of the proposed model. The groundwater potential map generated classified the study area into low, medium and high yield zones. Areas with medium potential zones dominate the largest part of the with 66% area coverage, and the dominance of these zones was visible in the northern and western part of the study area. Areas with high groundwater potential exist toward the southern and eastern sections of the study area. This area was observed to be underlined with sandstone, siltstone and migmatite. The validation exercise carried out on the proposed model reveals a 70% prediction accuracy.

Delineation of groundwater potential zones using a parsimonious concept based on catastrophe theory and analytical hierarchy process

A cost-effective “parsimonious” approach to delineating groundwater potential zones is proposed, based on catastrophe theory (CT) and analytical hierarchy process (AHP) in a geographic information system (GIS). Eleven indicators that influence groundwater storage (slope, drainage density, surface-water body (proximity), soil permeability, aquitard thickness, aquifer thickness, hydraulic conductivity, specific yield, recharge, aquitard resistivity and aquifer resistivity) were prepared. The suitable weights of the factors and the index values of the features of the factors were normalized using AHP and CT multicriteria decision analysis (MCDA) techniques for the development of a groundwater potential index (GWPI) map. Finally, the relative sensitivity of the factors was evaluated to develop a parsimonious groundwater potential index (P-GWPI) map using the most sensitive themes. GWPI and P-GWPI maps were validated using 14-year average annual post-monsoon depth to groundwater level data of 36 monitoring wells in a study area in Bangladesh. The generated GWPI map classified the study area as moderately good, good and very good groundwater potential covering an area of 19.5, 40.3 and 40.2% respectively. Subsequently, a modified GWPI map was developed using effective weights derived from single-parameter sensitivity analysis. The P-GWPI map developed using the most sensitive factors categorized the groundwater potential zones as moderately good (13.0%), good (38.2%) and very good (48.8%). The results of this study can serve as guidelines for future groundwater exploration, planning and management of the area, and the methodology used can also be easily adopted in other similar and data-scarce areas.

Delineation of groundwater zones with contrasting quality in the fluorotic zone, around Mount Meru, northern Tanzania

ABSTRACT Arumeru district (northern Tanzania) has limited low-fluoride surface water sources for domestic use. Information on the alternative source, groundwater, is also limited in terms of occurrence and quality. Thus, resistivity data in conjunction with hydrochemical data (fluoride, F−; total dissolved solids, TDS; and electrical conductivity, EC) and lithological logs were used to delineate groundwater zones with contrasting quality in the fluorotic zone. The results reveal a thin upper aquifer (~25 m thick) and a lower major aquifer (>100 m thick). Resistivity of 35–60 Ωm represents fresh groundwater hosted in weathered and fractured mafic volcanics, tuffs and breccias. Resistivity of 25–35 Ωm indicates intermediate groundwater quality, whereas resistivity of 15–25 Ωm indicates low groundwater quality (TDS >1000 mg/L, F− >10 mg/L) hosted in lahars. The results have been integrated to develop a groundwater potential index map, to guide local communities, water authorities and government in the planning and development of groundwater resources in the region.

Investigation of groundwater potential and groundwater pollution risk using the multi-criteria method: a case study (the Alaşehir sub-basin, western Turkey)

Determination of the groundwater potential (GWP) and groundwater pollution risk (GWPR) areas is a very important tool in the semi-arid regions in the world. Like many countries in the world, most of the major settlements in the cities of Turkey are located in permeable alluvial plains. Therefore, significant groundwater pollution is encountered in an alluvial plain containing settlements and industrial sites. This study focuses on the determination of the GWP and GWPR areas in the Alasehir sub-basin, which is one of the economically important districts of the Aegean region, located in the Gediz River basin in western Turkey. In this study, the GWP and the GWPR areas were identified and a GWP index map was generated. The GWP areas in the study basin were determined using different proxies as a multi-criteria method based on geographic information system (GIS) integrated with remote sensing (RS). The result of the study indicates that the most GWP locations in the basin are seen in the west and southeast of the study region. Based on these results, it is understood that the significant GWP and GWPR areas are near the big settlement districts such as Alasehir and Salihli. In particular, the 115-ha organized industrial zone located in the Salihli district is an important factor of the potential for consuming and contaminating water resources. This study method is so important for the selection of both city and industrial areas as well as for regional environmental planning in terms of the GWPR management.

Flowing well potential zoning at Iraqi southern and western deserts using frequency ratio and geographic information system

The objective of this study is to integrate geographic information system and bivariate frequency ratio method for the mapping of flowing well zones in the west and southwest parts of the Euphrates river basin of Iraq. Ten groundwater conditioning factors are identified as controlling factors of groundwater movement based on data availability, literature review, and expert’s opinions. The spatial association between flowing well locations and groundwater controlling factors is investigated by means of a probabilistic frequency ratio approach. Seventy percent or 148 wells from an inventory of 211 flowing wells in the study area are randomly selected for training, and the remaining 30 or 63% wells are used for validation of the probabilistic frequency ratio model. The estimated probabilistic ratio values are overlaid and summed to produce the groundwater potential index map. The results reveal that groundwater potential in 128,547 km2 or 84% of the total area is very low to low. The moderate potential zone covers an area of about 11,210 km2 or 7%, while the high and very high potential zones are found in an area of 12,982 km2 or 9% of the study area. Validation of obtaining results by means of a receiver operating characteristic technique reveals that the predictive accuracy of 94% indicating the excellent performance of the proposed approach for spatial zoning of groundwater flowing well boundary at Iraqi desert.

Grey analytic hierarchy process applied to effectiveness evaluation for groundwater potential zone delineation

An attempt has been made to identify plausible groundwater potential zones (GWPZ) based on Grey Analytic Hierarchy Process Method (Grey-AHP) using integrated remote sensing and geographic information system. Grey-AHP combines the advantages of classical analytic hierarchy process and grey clustering method for accurate estimation of weight coefficients. The method also examines the effectiveness of GWPZ identification process. The proposed methodology has been applied to the Hirakud canal command area, Odisha (India). Feature layers [e.g. soil type, geology] are utilized for groundwater potential index (GWPI) calculation. The resulting GWPI map has been classified into three GWPZ namely: good, moderate and poor. Effectiveness based on grey clustering method is found to be in between ‘better’ and ‘common’ classes. Value of coefficient of determination (R2 = 0.865) supports the obtained effectiveness evaluation result. This analysis demonstrates the potential applicability of the methodology for a general aquifer system.

Identification of groundwater potential zones considering water quality aspect

To evolve a proper management scenario for groundwater utilization, identification of groundwater potential zones is an important step. In the present study, an attempt has been made to identify possible groundwater potential zones both in terms of quantity and quality. A methodology is proposed for identification of groundwater potential index (GWPI) and a new water quality index (WQI) based on analytic hierarchy process. The proposed methodology has been applied to the shallow alluvial aquifer of central Ganga basin, Kanpur (India). Land use/land cover, soil, geology, recharge rate, drainage density, rainfall, slope, elevation, normalized difference vegetation index, groundwater depth or depth to groundwater table are used for GWPI calculation. Moreover, WQI considers alkalinity (as CaCO3), magnesium (Mg2+), total dissolved solids and fluoride (F−) as influencing attributes. Final integration of attributes yield GWPI and WQI map. The resulting GWPI map has been classified into three groundwater potential zones namely: good, moderate and poor covering 26.94, 43.76, and 29.30 %, area, respectively. The WQI map has been classified into five quality zones namely: above permissible limit, poor, moderate, good, very good covering 12.39, 7.63, 15.17, 38.18, and 26.64 % area, respectively. Monitoring data from well locations along with GWPI and WQI map reveals the proper potential zones. This analysis demonstrates the potential applicability of the methodology for a general aquifer system.

Delineation of groundwater potential zones in Araniar River basin, Tamil Nadu, India: an integrated remote sensing and geographical information system approach

The paper presents the development of a groundwater potential index (GWPI) map of the Araniar River basin, India, through an overlay analysis of climatic, geologic, geomorphic, soil and land use/land cover features of the basin using Landsat5 Thematic Mapper (TM) data and ArcGIS9.2. A correlation analysis of the developed GWPI map was carried out with a yield map of the basin to standardize the weights assigned to each theme. A maximum correlation coefficient of 0.922 was obtained when rainfall, geology, soil, slope, geomorphology and land use/land cover maps were overlaid with standardized weights of 0.49, 0.20, 0.17, 0.05, 0.05 and 0.04, respectively. The GWPI map showed groundwater potential zones as “excellent”, “very good”, “good”, “moderate” and “poor” with yield values in the ranges 293–361, 210–292, 126–209, 43–125 and 15–42 lpm, respectively. The analysis of post- and pre-monsoon water table depths also showed pronounced groundwater-level fluctuations in the central and eastern part of the basin. The GWPI map when combined with the post- and pre-monsoon water table depth maps may also help in locating suitable sites for artificial recharge for effective and efficient groundwater resource exploration and management of the basin.

Groundwater exploration using remote sensing and geographic information systems in a semi-arid area (Southwest of Urmieh, Northwest of Iran)

Shortage of water required for drinking and agricultural uses is a subject with a vital importance in most arid and semi-arid regions. The area of this study is one of the semi-arid regions located in southwest of Urmieh lake, northwest of Iran, between N 37°00′, 37°15′ latitude and E 45°05′, 45°30′ longitude which is composed of Permian dolomitic limestone, limestone, and post-Jurassic granite with a very low primary porosity/permeability character. In order to delineate groundwater potential zones in this area, the study focused on identifying secondary porosity/permeability indicators such as lineaments, vegetation cover, lithology, drainage pattern, drainage density, etc. In this regard, a remote sensing and geographic information system-based methodology was selected. Landsat ETM, IRS (pan), SPOT data, digital elevation model, and digital image processing techniques such as filtering, false color composite, principal component analysis, band rationing and classification have been applied to reach the purposes. Information layers extracted for analysis and interpretation stage were then integrated with other data and modeled through the use of existing geographic information system (GIS) software and their related analytical functions. Finally, based on determined ground water favorability index for different sub zones, layers, weighting, and overlapping, a ground water potential index (GWPI) was defined which respectively was utilized to groundwater potential zoning and preparation of GWPI map of the region. Within the six different sub zones defined, two sub zones labeled with high and very good potential areas were highly recommended for further development and exploration purposes. Geophysical investigations in target areas confirm the labeled subzones. Based on the obtained results of the study, it can be concluded that remote sensing data are very useful tool to extract information of groundwater exploration. Also, application of geographic information systems to find target areas for groundwater exploration are effective to save time and cost.