Understanding the Uncertainty of the Lim River Basin Response to Changing Climate

This study addresses how uncertainty propagates within climate models, statistical postprocessing tools, and the hydrological model, while taking into account the observed forcing and response of the hydrological system. Propagation of uncertainty is assessed using three regional climate models (RCMs), four bias correction methods (BCMs), two averaging methods, three representative concentration pathway (RCPs) scenarios, and a single hydrological model. The hydrological simulations are performed for the baseline period 1971-2000, and for the future time period 2006-2055. The Lim River basin in Serbia (southeast Europe) is selected as the study region. The dominant sources of uncertainty are the bias correction methods (9.7%-16.1%), whereas uncertainty from the choice of regional climate models is generally smaller (7.4%-13.9%). The results from the hydrological simulations for the future time period suggest relatively moderate annual changes in streamflows, from-6.3%to+12.5%under the RCP2.6, RCP4.5, and RCP8.5. The most significant changes are expected at the seasonal level, especially for the winter flows ranging from+27.1%to+35.7%. (c) 2020 American Society of Civil Engineers.