Hydrogeology of the Basin Granitoids in the Sekyere South District of Ashanti Region, Ghana

Abstract

The hydrogeology of the Basin Granitoids in the Sekyere South District of Ashanti Region of Ghana has been evaluated applying the electrical resistivity imaging (ERI) geophysical technique and pumping test analysis. The ERI was conducted to obtain information on resistivity distribution for groundwater accumulation and pumping test was used to obtain transmissivity and sustainable yields of boreholes. Results from the ERI technique show that the general resistivity distribution in the area is between (20 - 4000) Ω-m and the resistivity range that is related to groundwater occurrence is between (50 - 300) Ω-m for the weathered and (100 - 600) Ω-m for the fractured granitic rocks. The aquifers are generally shallow to medium depth and where resistivities of the aquifer zones are less than 400 Ω-m in the fresh granites, high yields are likely to be attained. Pumping test also revealed that transmissivity values range between (5.89 - 43) m2/day, with sustainable ...