Aquifer hydraulic characteristics using D-Z parameters: a case study of Lohaghat block, Champawat district, Uttarakhand, India

This study investigates the geoelectrical properties of shallow aquifers and estimates their hydraulic parameters in the Lohaghat block of the Champawat district, Uttarakhand. Twenty vertical electrical soundings (VES) were conducted with electrode separations (AB) spacing from 200 to 940 m. The data were processed using 1X1D Interpex software. The qualitative analysis revealed four primary geoelectric layer patterns, mainly HK and KH-type curves. The interpreted resistivities of layers ranged from 24.06 to 170.59 Ω-m, with an average resistivity of 80.64 Ω-m. The principal aquifer was found in the fourth to seventh geoelectric layers, comprising weathered or fractured phyllites, granite, quartzite, and sand. Aquifer depths ranged from 17.24 to 91.15 m, and its thickness ranged from 14.59 to 69.56 m. Hydraulic parameters derived from the geoelectrical properties indicated a porosity range of 37.81–56.14%, protective capacities between 0.12 and 1.07 mhos (average 0.45 mhos), and transverse resistance from 452.91 to 8272.25 Ω-m2. Transverse resistivities ranged from 6.73 to 208.53 Ω-m, longitudinal resistivities varied from 37.88 to 521.63 Ω-m, and anisotropy values ranged from 0.27 to 1.35. These parameters were utilized to estimate both hydraulic conductivity and transmissivity. Transmissivity values varied from 67.61 to 548.24 m2/day. By employing the Dar-Zarrouk (D-Z) parameters, which encompass the aquifer thickness, resistivity, hydraulic conductivity, transmissivity, longitudinal conductance, transverse resistance, and anisotropy, the groundwater potential was assessed, categorizing the area as having moderate and good productivity. This study demonstrates the utility of the surficial geoelectrical method in assessing the shallow aquifer characteristics in the Lohaghat block of Uttarakhand, identifying areas with potential groundwater resources without the need for conventional pumping tests and adding water resource management.