Suspended Sediment simulation model for Pangani river.

Abstract

A Universal Soil- Loss Equation was developed using available information from topographical, vegetation, soil, crops and Isohyetal maps, Meteorological data, etc. The model estimates suspended sediment from a study area of 10,935 Km2 starting from station 1D8A at the down stream of Nyumba ya Mungu reservoir to station 1 D 14 at Korogwe. The model input parameters includes the Rainfall Erosivity Index (R), which was estimated by using Foster et al, (1981) formulas, the Erodibility Index (K), estimated using Quansah, (1981), Slope Factor (LS), estimated from topographical maps, the Crop Factor (C) and the Conservation Practice Factor (P), both from Morgan and Finney method of predicting soil loss. The model performance was assessed using graphical plots of observed and simulated hydrographs and the coefficient of efficiency by Nash and Sutcliffe (1970). This gave an efficiency criteria (R2) of 68 percent, this was satisfactory as far as sediment transport was concern.