Forecasting Water Inflow into the Tsimlyansk Reservoir during Spring Flood under Current Climate Conditions: Problems and Reproducibility

Abstract

Studies of water balance and variations of water regime of rivers in the Don Basin have shown a steady trend toward a decrease in spring flood volumes and an increase in runoff volume in winter since the mid-1980s. More frequent thaws have resulted in that snowmelt runoff formation can be seen almost throughout winter. A decrease in soil moisture content in the late October along with a decrease in the maximal freezing depth in the major portion of the basin increases water losses during thaws and at the early stages of spring flood. At a considerable decrease in the water equivalent of snow cover along with an appreciable increase in water losses, spring flood will not occur in some years. Therefore, changes in the climate and anthropogenic load considerably reduce the reliability of relationships developed in the XX century and used to forecast the spring inflow into the Tsymlyansk Reservoir.