Rainfall and water resources of a coastal basin of Ghana

Abstract

Temporal distributions as well as spatial variability of rainfall have been investigated within the Densu River basin in Ghana to determine the duration pattern of rainfall events and their intensities and how these affect the partitioning of rainfall into overland flow and infiltration. Also, the use of daily rainfall data (mm/day) as inputs in physically based hydrological models for water balance computation and description of hydrological processes in the basin was assessed in relation to the actual duration of rainfall events in the basin. The threshold intensities for groundwater recharge in the Birimian, Granite, and Togo formation soils are below 70 mm/h, 85 mm/h, and 95 mm/h, respectively, and above 10 mm/h in the entire basin. The amount of rainfall infiltrating into the groundwater system will diminish in the future because of the imminent effects of climate change on the intensity of rainfall events. © 2011 American Society of Civil Engineers.