Managing climate risks: New evidence from integrated analysis at the basin scale

Abstract

Safe, reliable, and equitable water access is critical for sustaining healthy livelihoods. Climate water stress is a growing challenge internationally making it difficult to achieve sustainable management of river basins. Addressing the problem requires integrated multi-sector water management strategies for climate resilience. The Water-Energy-Food-Ecosystems (WEFE) nexus offers promise as a comprehensive framework to guide science-based plans to achieve sustainable development goals. Several nexus approaches have been proposed in previous works. However, none to date has conceptualized, formulated, tested, validated, and applied a comprehensive dynamic optimization framework that includes several water-using sectors including ecosystems for a significant river basin supporting livelihoods of large numbers of people. The original contribution of this paper is to make headway on filling these gaps, taking Spain’s Ebro Basin as a case study, providing evidence to guide science-based policy reform. This work’s innovations illustrate the previously untested use of information to guide proposed water allocations among several economic sectors including protection of key ecological assets. Results provide a rigorous framework for measuring the level and distribution of benefits and costs among sectors and stakeholders. Findings reveal a range of policy choices that improve the hydrologic and economic performance of water management compared to the current policy for addressing climate change. Policy options that systematically account for the full range of benefits of environmental flows guide science-informed strategies for guiding climate resilience planning. They can increase stream flows in rivers, enhance water security and biodiversity, and reduce the economic burdens imposed by climate risks.