IMPACT OF CLIMATE CHANGE ON HYDROLOGICAL AND METEOROLOGICAL QUANTITIES IN WATERSHED SCALE

Abstract

Climate change�s effect on nature, the human population and water resources have become a serious issue. It affects the delicate balance between precipitation, evaporation, discharge and other interactions between the atmosphere and surface, which is represented by the water cycle as we know it. The adaptation of water resources to changing hydrological conditions within basins is crucial. However, the uncertainty of climate change makes it difficult for hydrological models to evaluate future conditions. To suppress the uncertainty that stems from the hydrological model itself, we propose a new modified lumped water balance model in monthly time steps to simulate the rainfallrunoff process more precisely, which will help to evaluate the predicted hydrological and climatological conditions under the uncertainty of climate change. Assessment of the effects of climate change is presented on the catchment above the Vir I reservoir on the Svratka River in the Czech Republic in Central Europe. The uncertainty of climate change is represented by an ensemble of future climatological projections using representative concentration pathways (RCP) scenarios. Two ensembles were generated: the first using RCP 4.5 and the second using RCP 8.5. Both scenarios were coupled with 18 global climate models which are available in LARS-WG 6 software. Analysis of the generated climatological quantities for both ensembles in the 2030s, 2050s, and 2090s periods on annual average relative to baseline values showed an increase in mean temperature of 21.4% (1.4�C), 33.1% (2.2�C) and 55.5% (3.7�C), an increase of potential evapotranspiration of 7.2%, 11.4% and 20.5%, and an increase in precipitation of 4.8%, 5.3% and 5.5%, respectively. Evaluated long-term mean streamflow showed a decrease in the 2030s, 2050s and 2090 of 1.0%, 3.1% and 2.9%, respectively, for RCP 4.5 and an increase of 1.8% in the 2030s but then also a decrease in the 2050s and 2090s of 2.3% and 17.9%, respectively, for RCP 8.5.