Simulation of extreme rainfall and streamflow events in small Mediterranean watersheds with a one-way coupled atmospheric- hydrologic modelling system Corrado Camera1, Adriana Bruggeman2, George Zittis3, Ioannis Sofokleous2, and Joël Arnault4 5 1 Dipartimento di Scienze della Terra ’A. Desio’, Università degli Studi di Milano, Milano, 20133, Italy 2 Energy Environment and Water Research Center, The Cyprus Institute, Nicosia, 2121, Cyprus 3 Climate and Atmosphere Research Center, The Cyprus Institute, Nicosia, 2121, Cyprus 4 Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Garmisch‐Partenkirchen, 82467, Germany 10 Correspondence to: Corrado Camera (
[email protected]) Abstract. Coupled atmospheric-hydrologic systems are increasingly used as instruments for flood forecasting and water management purposes, making the performance of the hydrologic routines a key indicator of the model functionality. This study’s objectives were: (i) to calibrate the one-way coupled WRF-hydro model for simulating extreme events in Cyprus with observed 15 precipitation; and (ii) to evaluate the model performance when forced with WRF-downscaled (1 × 1 km2) re-analysis precipitation data (ERA-Interim). This set up resembles a realistic modelling chain for forecasting applications and climate projections. Streamflow was modelled during extreme rainfall events that occurred in January 1989 (calibration) and November 1994 (validation) over 22 mountain watersheds. In six watersheds, Nash-Sutcliffe Efficiencies (NSE) larger than 0.5 were obtained for both events. The WRF-modelled rainfall showed an average NSE of 0.83 for January 1989 and 0.49 for 20 November 1994. Nevertheless, hydrologic simulations of the two events with the WRF-modelled rainfall and the calibrated WRF-Hydro returned negative streamflow NSE for 13 watersheds in January 1989 and for 18 watersheds in November 1994.