River Runoff in European Russia under Global Warming by 1.5 and 2 Degrees

The ECOMAG hydrological model was used to evaluate runoff characteristics in the basins of the major rivers in European Russia: the Volga, Don, Northern Dvina, Pechora, and Kuban. The models of runoff formation for various hydrometric gauging stations in these basins were calibrated using data of weather station observations. Next, the input data were represented by the data of an ensemble of global climate models for assessing the regional hydrometeorological regime at the realization of a scenario of global warming by 1.5 and 2°C in the XXI century relative to the preindustrial values. The reproduction of the annual and seasonal runoff by data of climatic models was evaluated by comparison with observation data. According to the results of numerical experiments at global warming by 1.5 and 2°C, the values of the relative changes in river runoff in European Russia increase from N to S and from E to W, i.e., the hydrological systems under milder climate were found to be more sensitive to changes in the meteorological characteristics. The estimation of runoff anomalies in the European Russia showed the following common features: an increase in the winter runoff in the northern rivers and in the Volga basin, a decrease in the spring snowmelt runoff in the Northern Dvina, Volga, and Don, a decrease in the summer–autumn runoff of all studied rivers with various intensity. In this case, the annual runoff of the Pechora will show a positive trend, and that of the Northern Dvina, Volga, Don, and Kuban, a negative trend.