Decision Analytic Approach to Resolving Divergent Climate Assumptions in Water Resources Planning

Climate nonstationarity and uncertainty raise important issues related to design and planning within the water sector. Participants in the planning process may not all agree on what climate assumptions and planning objectives should be included. This undermines the group's ability to seek and agree upon a solution. This paper addresses this problem by proposing a decision analytic framework designed to facilitate direct comparison among sets of candidate water management strategies that maximize performance based on a range of different climate assumptions and ways of measuring robustness to climate change uncertainty. In a simplified example, floodplain management decisions based on the Iowa River candidate flood risk management (FRM) adaptation sequences are selected through a range of optimization-based planning approaches that are developed to represent alternative underlying climate assumptions. The resulting candidate adaptation sequences are then analyzed in terms of performance under alternate climate assumptions and through a climate stress test. The decision analytic model may be useful for seeking resolution among water planning participants who disagree on future climate scenarios.