Groundwater Flow Direction, Recharge and Discharge Zones Identification in Lower Gidabo Catchment, Rift Valley Basin, Ethiopia

Abstract

Groundwater is occurring in different geologic formations and topographic features, those factors mostly control the distribution and development of groundwater. In this study, groundwater potential of the catchment was investigated with exploring groundwater flow direction, recharge and discharge zones. The study embattled to understand comprehensive aspects of groundwater potential and hydrogeological features of the catchment. Surfer 8 and Arc GIS 9.3 programs were used for the study to realize groundwater flow direction, recharge and discharge zones. Arc GIS was too used for geo referencing and mapping of the catchment. Groundwater flow direction of the catchment was identified by using groundwater level maps. According to groundwater flow lines and contour maps, groundwater flows from eastern highland parts of the catchment towards the plain areas in the western direction. As per the result perceived, the major recharge of groundwater occurs in Eastern and Northeastern highlands of the catchment, which is said to be recharging zone. However, the area situated in Western and Northwestern parts of the catchment are discharge zones. Therefore, dumpsites could be sited out of southeastern, southern and northeastern parts of the catchment to minimize groundwater contamination. As well, hand dug well for potable water supply could not be placed in Southeastern and eastern escarpment of the catchment.

Keyword: Groundwater recharge and discharge zone, Lower Gidabo catchment, flow direction; Surfer and Geographic Information system