Geophysical techniques for aquifer characteristic studies- a case study of Perumatty grama panchayath in Kerala

Abstract

Groundwater exploration and management are critical due to the increasing demand and over-exploitation of this vital resource. Electrical resistivity surveying, a geophysical method, has proven to be an effective technique for subsurface investigations, including groundwater detection. This thesis presents the application of electrical resistivity methods in groundwater exploration in Perumatty Grama Panchayath, Palakkad, Kerala. The methodology involved Vertical Electrical Sounding (VES) and resistivity imaging to identify and delineate groundwater potential zones. A total of 13 locations were surveyed using the Schlumberger electrode configuration. The resistivity data were interpreted using IPI2WIN software, resulting in the identification of three types of sounding curves: H-type, K-type, and A-type. H-type curves (ρ1 > ρ2 < ρ3) were observed in five locations (L4, L7, L8, L9, and L11), indicating good aquifer characteristics with lower resistivity in the middle layer. K-type curves (ρ1 < ρ2 > ρ3) were found in five locations (L1, L3, L6, L10, and L13), showing high resistivity in the middle layer, indicating hard rock formations with clayey soil in the top and bottom layers. A-type curves (ρ1 < ρ2 < ρ3) were observed in three locations (L2, L5, and L12), indicating hard rock in the third layer and clayey soil in the first and second layers. The study successfully identified aquifer zones and provided insights into the subsurface geology of Perumatty Grama Panchayath. The H-type and A-type locations showed comparatively higher groundwater potential in both the top and middle layers. These findings demonstrate the efficacy of electrical resistivity methods in hydro-geological studies and highlight their importance in sustainable groundwater resource management. The results suggest that the electrical resistivity method is a reliable tool for identifying groundwater potential zones, which is essential for effective groundwater management in the study area.