Groundwater Resources as a Resilient Alternative for Irrigation in the Upper West Region of Ghana – A Study of Groundwater Potential

Abstract

Groundwater use has increased substantially for both domestic and agricultural purposes in the growing communities of Ghana. The way climate change has treated agriculture in some parts of Africa; it can possibly sabotage food security if policies on groundwater irrigation are not adopted. Geology of the Birimian is known for its high-moderate groundwater potential. This kind of formation occurs in the Northwestern corner, the middle portion and some parts in southern Ghana. Previous study has suggested that there are more than 779 functional boreholes that exist within the study area. The groundwater potential within the study area was studied using typical hydrogeological factors such as; groundwater resistivity, overburden thickness, borehole success rate and groundwater pumping rate. Resistivity values between 38.480 ohm.m – 103.740 ohm.m showed areas of fresh to brackish groundwater resource having a saturated thickness ranging from 13.79 m to 16.27 m. Information regarding borehole depth indicates that places of high SWL (20.60 m) probably has shallow depth and places of low SWL (18.75 m) are likely to have deeper depth. Generally, areas within Tegberi and Tumu are known for its high success rate. The storage capacity and the extractble storage were estimated to be approximately 134.9 x 10³ km³ and 53.23 x 10³ km³ respectively for the aquifer basement complex of the 35 boreholes. The research targeted areas of high groundwater success rate so as to minimise the gap in the computation that may be affected as a result of the dry boreholes. The pumping rate showed that large quantity of groundwater was discharged from the boreholes; hence the exploration of groundwater as an alternative water supply for irrigation and agricultural production within the Upper West Region might be feasible.