Methodology based on modelling processes and the characterisation of natural flows for risk assessment and water management under the influence of climate change

Abstract

Abstract. Climate change and its possible effects on water resources has become an increasingly near threat. Therefore, the study of these impacts in highly regulated systems and those suffering extreme events is essential to deal with them effectively. This paper responds to the need of an effective methodology that integrates the climate change projections into water planning and management to guide complex basin decision-making through drought risk and management assessments. In this study is presented an adaptive method based on a model chain and correction processes, where the main outcomes are the impacts on future natural inflows, a drought risk indicator and the simulation of the future water storage of the water resources system (WRS) under consideration. The proposed methodology was applied in the Júcar River Basin (JRB) due to its complexity and the multiannual drought events it goes through. The results shown a decreasing tendency of future inflows to the basin, and the drought risk indicator shows a high probability (≈ 80 %) of being under 50 % of total capacity of the WRS in the near future, but the uncertainty is considerable from the middle century onwards, indicating that an improvement in the skill of climate projections is required. Thus, this paper also highlights the difficulties of developing this type of methods, since the conclusions on climate change impact assessment depend on partial decisions taken during the methodological processes. However, the main results call for action in the JRB and the tool developed can be considered as a feasible option to facilitate and support decision-making in future water planning and management.