Evaluation of drought representation and propagation in Regional Climate Model simulations over Spain

Abstract

Abstract. Drought is an important climatic risk, of complex modeling due to the interaction of different processes and their corresponding temporal scales. It is expected to increase in intensity, frequency and duration due to a warmer climate. Therefore, it is vital to know the evolution of drought in relation to climate change. For this, the better understanding of processes involved in it is key. The study here presented, analyses drought representation and propagation by regional climate models from Med-CORDEX simulations by means of standardized indices. The models used are RCSM4, CCLM4, and PROMES. Focus is made on three types of drought: meteorological, soil moisture and hydrological. Results show that these models improve meteorological drought representation, but large uncertainties are identified in its propagation and the way soil moisture and hydrological droughts are characterised. These are mainly due to the relevance of model formulation. For instance, it affects the temporal scale at which precipitation variability propagates to soil moisture and streamflow. In addition, downscaling is also seen to affect streamflow variability, and thus hydrological drought.