Climate Change Impact Evaluation on the Water Balance of the Koroška Bela Area, NW Slovenia

Climate change is expected to affect the elements of the hydrological cycle, which are also related to the landslides and debris flows triggering mechanics. In the scope of this contribution, we evaluated climate change impact on the water balance components in the hinterland of the Koroška Bela (NW Slovenia), which is one of the endangered settlements in Slovenia. For this purpose, we focused on the representative concentration pathway (RCP) RCP4.5 scenario, which can be described as a midway scenario. Lumped conceptual hydrological model was used in order to model the relationship between the hydrological cycle elements. Moreover, climate change impact on the intensity-duration-frequency (IDF) curves was also estimated. The results indicate that total rainfall as well as effective rainfall could increase in the future. Mainly due to air temperature increase, we could see an evapotranspiration increase in the future. Moreover, hydrological model results indicate a possible surface runoff increase from the Bela stream catchment. However, these changes are mostly in the range of the 5% with the exception of the air temperature data where difference between future and past is larger. Furthermore, subsurface water storage included in the model indicates that only slight changes in the wetness of the catchment might be expected. Additionally, climate change could also affect the extreme rainfall characteristics, which can be seen as a change in the IDF curves. However, these changes are relatively small.