Groundwater flow modeling in the Akyem area, Southeastern, Ghana

Abstract

Hydrogeological information from previous work and detailed geophysical analysis were used with a steady state groundwater flow simulation model to describe the hydrogeological conditions of aquifers in the Akyem area, southeastern Ghana. This series of investigations indicates that the groundwater resources of aquifers in this area are based on the intensity of secondary permeability resulting from weathering and fracturing. Aquifer transmissivity varies from 2.13 to 18 m2/day with an average of 7.67 m 2/day, and relates strongly with specific capacity after twelve hours of pumping. Well yield correlates poorly with depth, which suggests that the water bearing structures are discrete entities which are not evenly distributed with depth. The flow simulation model reveals local, intermediate and regional flow systems. Groundwater contours follow the pattern of the topography, and range from 130 m to 180 m above sea level. There is a general flow from NE to SW. However, due to the heterogeneity of the aquifers and their dependence on secondary permeability, such as fractures and quartz veins among others, for groundwater storage and transmission, there are many barriers to continuous groundwater flow laterally as well as with depth and this is clearly displayed in the flow simulation model. The distribution of the hydraulic heads in the area, however, indicates significant opportunities for groundwater extraction for various uses.