Determination of aquifer properties and vulnerability mapping by using geoelectrical investigation of parts of Sub-Himalayas, Bhimber, Azad Jammu and Kashmir, Pakistan

Abstract

A resistivity survey has been carried out for the determination of aquifer properties and vulnerability mapping of part of the Sub-Himalayas in the Bhimber District of Azad Jammu and Kashmir, Pakistan. In the study area 19 vertical electrical sounding points were established using a Schlumberger configuration. The acquired data were processed using IPI2WIN software and interpreted in terms of true resistivity and thickness of layers. The underlying lithology is loose soil, sandy clay, clay and sand. Productive groundwater zones have been identified in the central, southeastern and northwestern parts of the study area. The aquifer thickness varies considerably (6.4–224 m). On the aquifer vulnerability map, values >0.2 mhos indicate zones of moderate to good protective capacity, whereas values <0.19 mhos indicate vulnerable zones with risk of contamination. However, the aquifer is permeable and the central part has a low protective capacity and is vulnerable to infiltration of polluted fluid. The 2D resistivity inverse model and conductivity mapping delineate the contaminated plumes in the areas of poor to weak protective capacity. Chemical analysis shows that the central part of the study area is highly contaminated with magnesium, nitrate and sulphate.

A Comparison Between Schlumberger and Wenner Configurations in Delineating Subsurface Water Bearing Zones: A Case Study of Rawalakot Azad Jammu and Kashmir, Pakistan

“…Moreover, it can be used either in the form of vertical electrical soundings (VES's) or horizontal profiling to search for groundwater. The resistivity method is less costly and very suitable for the demarcation of subsurface water-bearing strata and feasible sites for the installation of water bores (Adeyemo et al, 2017;Niaz et al, 2013).…”

“…The maximum electrode spacing at various locations ranged up to 200 meters. The data were also employed for the development of longitudinal transverse and anisotropy maps of the area to observe the effects of homogeneity (Alisiobi and Ako, 2012;Ariyo et al, 2011;Niaz et al, 2013;Niaz et al, 2017).…”

“…Transverse resistance is defined as the total resistance through one meter column cut perpendicular to the bedding plane. It is denoted by 'T' and its unit is Ω/m (Niaz et al, 2013).…”

“…The different methods used to estimate the hydrological parameters are costly and timeconsuming. Geophysical techniques provide a costeffective measurement to estimate aquifer parameters and groundwater potential (Khalil, 2009;Niaz et al, 2013;Oseji et al, 2005). These techniques are common dynamic scientific lines that govern the hydrogeological investigation.…”

A Comparison Between Schlumberger and Wenner Configurations in Delineating Subsurface Water Bearing Zones: A Case Study of Rawalakot Azad Jammu and Kashmir, Pakistan

“…These techniques are common dynamic scientific lines that govern the hydrogeological investigation. They are not only restricted to the hydrological parameters like longitudinal conductance, transverse resistance, bedrock depth, but also give indications about the occurrence of freshwater (Khan et al, 2018;Niaz et al, 2016;Niaz et al, 2018).…”