A procedure for the quantitative assessment of water resources management under climate change and the design of adaptation measures

The pressure on water resources has tremendously increased in the last decades and waterstress is expected to further augment in many part of the world due to multiple social, economicand climatic factors. Climate change (CC) will play a key role in determining water availabilityespecially in those countries where other drivers like population growth or economic conditionsare rather stable. A huge research effort is undergoing to better understand how CC may affect thehydrological cycle. In this paper, we propose and apply a procedure on the basin of lake Como,Italy, to assess the impact of CC on water-related activities. Traditionally, this is done combiningmodel-based approaches (e.g. downscaling of GCM outputs coupled with hydrological models toobtain future discharge scenarios) and qualitative evaluations (e.g. visual inspection of simulateddischarges). In the proposed procedure, quantitative assessment is extended from hydrologicalvariables to the impact on human activities via simulation of the entire water system and evaluationof the impacts on flooding, agriculture, ecosystems, etc. through performance indicators. Asthis procedure allows for a quantitative, transparent evaluation of different management policiesunder CC scenarios, it also opens the way to a rigorous design of adaptation measures taking intoconsiderations future discharge scenarios on the one hand and Stakeholders’ needs on the other.