Conceptual and Analytical Framework

Land use changes, especially intensification of rainfed agriculture, are driven by the need to improve agricultural production and livelihoods. One such land use change is adoption of RHM systems, which aim to enhance soil moisture and runoff storage for food production. RHM systems retain additional runoff on agricultural lands which 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 the dry period. However, depending on the level of up-scaling, RHM may lead to water scarcity and related conflicts among different users and uses. Therefore, whilst improving agricultural productivity is a priority to feed the growing populations, the ensuing water crisis is becoming a nightmare and a real policy challenge in many countries. The chapter presents a people-water-ecosystem nexus based conceptual framework for assessing the impacts of land use changes in upper Ewaso Ng&s;iro river basin in Kenya. The conceptual framework presents the key issues, their interactions and how they can be addressed to enhance integrated water resources management. It assesses the hydrological impacts of land use changes on hydrological regime in a river basin. Hydrological scenarios based anticipated impacts of land use changes are presented. The results will enhance formulation of sustainable land and water resources management policies for water-scarce river basins.