Land use changes and hydrological impacts related to up-scaling of rainwater harvesting and management in upper Ewaso Ng’iro river basin, Kenya

Some land use changes are driven by the need to improve agricultural production and livelihoods. Rainwater harvesting and management is one such change. It aims to retain additional runoff on agricultural lands for productive uses. This may reduce river flows for downstream users and lead to negative hydrological, socio-economic and environmental impacts in a river basin. On the other hand, rainwater storage systems may lead to positive impacts by reducing water abstractions for irrigation during dry periods. This paper presents a conceptual framework for assessing the impacts of land use changes in the upper Ewaso Ng’iro river basin in Kenya. It is based on a people–water–ecosystem nexus and presents the key issues, their interactions and how they can be addressed. The paper presents hydrological assessment of up-scaling rainwater harvesting (HASR) conceptual framework, which assesses the impacts of land use changes on hydrological regime in a river basin. The results will enhance formulation of sustainable land and water resources management policies and strategies for water-scarce river basins.