To dam or not to dam? Actionable socio-hydrology modeling to inform robust adaptation to water scarcity and water extremes

Abstract

The contribution of this paper is twofold: 1) it develops a replicable socio-hydrology-inspired model that elicits agents’ preferences while accounting for the two-way feedbacks between complex human and water systems; and 2) it integrates the resultant socio-hydrology model into robustness-based frameworks to inform the adoption of policies that show a satisfactory performance under most plausible futures. The socio-hydrology model is used to produce a database representing multiple plausible futures that quantifies uncertainty regarding scenario assumptions under alternative adaptation strategies. Using a robust decision-making framework, the mechanistic outputs from the database of plausible futures are combined with heuristic methods through experts’ knowledge and opinion to co-design scenarios, identify vulnerabilities and quantify tradeoffs of proposed strategies, and subjectively propose new scenarios and choose the preferred adaptation strategy. Methods are illustrated with an application to the Cega Catchment in central Spain, one of the few major catchments in central Spain that remains non-regulated, and where the construction of a major dam has been projected. Following a robust decision-making process informed by our socio-hydrology model and involving all key parties to the decision, the status quo strategy (no dam construction) was revealed preferred.