Despite the apparently desperate situation of sub-Saharan Africa, rainwater harvesting and management is a viable intervention for upgrading rain-fed agriculture, improving water supply and sustainable livelihoods in water-scarce river basins. If strategies are developed to ensure equity allocation of basin water, a win-win situation for diverse water users can be achieved. This thesis assesses the hydrological impacts of land use changes on water resources management and socio-economic development of the upper Ewaso Ng’iro river basin in Kenya. It considers the impact of irrigation on dry season river flows and highlights the challenge of flood storage strategies. While flood storage can reduce dry season irrigation water abstractions by more than a half, without affecting hydro-ecological functions downstream, unplanned flood harvesting may impact negatively on flood flow, being detrimental to natural ecosystems and groundwater downstream.
1. Introduction 2. Research Background and Study Area 3. Conceptual and Analytical Framework 4. Agro-hydrological Assessment of On-farm Storage RHM Systems 5. Agro-Hydrological Assessment of In-Situ RHM Systems 6. Hydro-Economic Analysis and Farmers’ Investment Options 7. Flood Storage and River Water Abstraction 8. Conclusions and Recommendations
Stephen N Ngigi was born in Nyandarua, Kenya in 1967. He obtained his B.Sc. (Hons) in Agricultural Engineering from the University of Nairobi in 1992, and an M.Sc.(Soil and Water Engineering) from Nairobi in 1996. His main interest is in rainwater harvesting management systems in semi-arid environments. Dr Ngigi is a respected advocate of locally-designed irrigation systems.