A hydrologically-driven approach to climate change adaptation for multipurpose multireservoir systems

Abstract

Climate change can significantly affect water systems with negative impacts on many facets of society and ecosystems. Therefore, significant attention must be devoted to the development of efficient adaptation strategies. More specifically, the reoperation of water resources systems to keep the overall performance within acceptable limits should be prioritized to avoid, or at least delay as much as possible, costly infrastructural investments. This manuscript presents a hydrologically-driven approach to support the reoperation of multipurpose multireservoir systems. The approach is organized around 1) the use of a large ensemble of GCM hydro-climate projections to drive a climate stress test; 2) the bottom-up clustering of those hydrologic projections based on hydrologic attributes that are both relevant to the region of interest and interpretable by the operators; and finally, 3) the identification of adaptation measures for each cluster after developing a one-way coupling of an optimization model with a simulation model. The climate impact assessment is illustrated with the multipurpose multireservoir system of the Lievre River basin in Quebec (Canada). Results show that cluster-specific, adapted, operating rules can improve the performance of the system and reveal its operational flexibility with respect to the different operating objectives.