Hydrometeorological impact of climate change in two Mediterranean basins

The impact of climate change in specific hydrological issues is investigated in two Mediterranean watersheds of the island of Crete, Koutsoulidis, and Giofyros, by using the HBV hydrological model. Koutsoulidis basin is analysed in terms of future water resources availability under climate change, as it supplies the dam of the surrounding area that provides its irrigational water needs. Giofyros is a basin prone to flooding, hence, it is analysed in terms of spring flood risk under climate change. At first, the HBV model is calibrated using as input the historical data. Next, the climate change impact is studied, using the HBV with climate data from 11 GCM–RCM combinations for 3 RCP scenarios (2.6, 4.5, and 8.5 W/m2) and 3 time windows (1981–2010, 2021–2050, and 2071–2100). The climate change impact to the hydrological systems’ behaviour is projected using several hydrometeorological parameters and hydrological signatures. Specifically, in Koutsoulidis basin, projections of future water resources availability show that the period of May to November is a high-risk period of water shortage for all RCPs in all time windows. In Giofyros basin, spring flood risk analysis reveals higher flooding risk in 2021–2050 time window. In addition, February is the most frequent month of spring flood start point in all climate scenarios. The above findings could be used in strategic planning for a sustainable water resources management in the Mediterranean basins.