Abstract for: Adaptive investment pathway for farmer security: group modeling of sand river based social-ecological systems of Eastern Africa

Shallow alluvial aquifers formed by ephemeral sand river beds are a significant yet underutilized water resource in semi-arid regions of Eastern Africa. Our objective is to develop an innovative adaptive investment pathway to plan incremental nature-based solutions to enable fresh water access for smallholding farmers, increasing farm productivity and food security. Rooted in systems thinking, the adaptive investment pathway is an action plan for an uncertain future which calls for deep understanding of the system structure to anticipate different scenarios and develop a corresponding action plan, as opposed to making large upfront investments. A group modelling exercise was conducted to develop a causal loop representation of the focal system in a participatory process involving stakeholders from government, non-government, local community and academia of Kenya and Ethiopia. Four key feedback loops were identified – a virtuous cycle of profitability by agricultural intensification, balancing loops of water availability and water regulation and a vicious loop of sand harvesting. Sand harvesting is an important economic activity but it negatively impacts water availability. A significant output was the identification of its risk to potential investments. There is need to further evaluate a “sustainable” threshold of sand harvesting below which water availability is not impacted significantly.