Simulating Runoff Formation in Mountain Crimea Rivers under Current and Projected Climate Conditions

ECOMAG runoff formation model was used to calculate physically based changes in river water regime in the Mountain Crimea with the use of data of an ensemble of climate models, taking into account various scenarios of global warming. The objects of the study were the rivers of Chernaya, Belbek, Derekoika, Alma, Salgir, Burulcha, Tonas, Kuchuk-Karasu, and Indol. The formation models of natural river runoff for this set of river basins were constructed based on homogeneous sources of data on the hydrometeorological regime and parameters of the land surface. The hydrological models were verified by comparing the actual and calculated daily and monthly water discharges at various hydrometric gages over a many-year period. Next, hydrological models and the data of an ensemble of global climate models for the base period of 2006–2020 were used to calculate future scenario changes in river runoff over a year and conventionally warm and cold seasons of a year. At the implementation of any of RCP-scenarios in the nearest future for 2021–2050, as well as for scenarios RCP 2.6 and RCP 4.5 in the late XXI century, deficiency of water resources can be faced mostly in river basins east of the Salgir upper reaches, however, not reaching catastrophic levels. According to more aggressive climate scenarios RCP 6.0 and RCP 8.5, in the late XXI century, a largest decrease in the river runoff of the mountain Crimea is likely, which will contribute to deficit of water resources due to atmospheric sources.