Simulation of rainfall, runoff, peakflow and soil loss in the upper Gambia River Basin.

Abstract

A number of West African river basins are under study for management and development of major projects such as irrigated agriculture supported by dams and reservoirs. For many of them the darns exist or are being built, on the Senegal river basin for example. The Gambia river basin management process is one of the latest and need major basic studies especially in hydrology and watershed management. This study is a contribution for the hydrologic analysis and modeling of the Gambia river upper basin. The study assesses the distributions and the statistics of recorded rainfall data and simulates long term sequences of data. Correlations between rainfall depth and rainfall duration then others between rainfall duration and rainfall excess duration are defined for time to peak and peakflow computation. It assesses as a first step towards further studies runoff and soil loss. One of the major problems that threaten the dams and reservoirs in that West African region is the erosion and sediment transport.