Application of hydrological conceptual models to simulate future river flows feeding Lake Victoria, East Africa

Proceedings of the Seventh International Conference on Hydroscience and Engineering, Philadelphia, PA, September 2006. http://hdl.handle.net/1860/732The Nile River receives its water primarily from Lake Victorias catchment basin, and is a particularly vital source of potable water in that region. Since greenhouse gases induce climate change that will affect the water resources system, this necessitates a fundamental review of both the planning and management of water resources. This study delivers the range of plausible changes in flows of five rivers (tributaries) to Lake Victoria from the year 2010 to 2099. Two different hydrological conceptual models, namely IHACRES and SMAR, are used in establishing the daily rainfall-runoff relationships for the five sub-catchments (tributaries) within the Lake Victoria basin. The five catchment sites are Nzoia, Yala, Sondu, Gucha and Mara. A number of climate change scenarios from several General Circulation Models (GCMs), taking into account different CO2 emission forcings have been successfully used by these hydrological models in order to simulate the corresponding future river flows in the five subcatchments. The results suggest an increase in mean annual flow in the 2020s period. However, the river flow trends in the 2050s and 2080s are inconclusive. The results show the potential for climate change to modify river flows, thus requiring a significant planning response. The results, amongst others also indicate the importance of considering hydrological impacts in potable water supply and flood/drought studies