Analyzing Catchment Behavior through Rainfall-Run-Off Modeling: A Case Study of Mara Basin in Kenya

Abstract

Hydrological models nowadays are considered as an important and necessary tool for water and environment resource management. However, the challenge facing modelling is in poorly gauged watersheds. Research done recently has shown potential to overcome this challenge through incorporating satellite based hydrological and meteorological data in the measured data. This research has used the semi-distributed conceptual HBV Light Model to model the rainfall-run-off in the Mara River Basin. The model simulates run-off as a function of rainfall. It is built on the basis established between satellite observed and in-situ rainfall, evaporation, temperature and the measured run-off. The model’s reliability was evaluated over two sub-catchments namely; Nyangores and Amala in the Mara River Basin using Nash - Sutcliffe Efficiency which the model referred to as Reff and the coefficient of determination (R2). The Reff for Nyangores and Amala during the calibration and (validation) period were 0.65(0.68) and 0.59(0.62) respectively. The model showed good flow simulations in particular during the recession flows, in the Nyangores sub-catchment whereas it simulated poorly the short term fluctuations of the high-flow for Amala sub-catchment.