Climate Change Effects on River Flow in Eastern Europe: Arctic Rivers vs. Southern Rivers

Abstract

The hydrological model ECOMAG was used to calculate runoff characteristics in the main arctic (Northern Dvina and Pechora) and southern (Don and Kuban) river basins of Eastern Europe using the data from the ensemble of global climate models under the scenario of 1.5 and 2 °C global warming in the 21st century relative to pre-industrial values. Flow generation models were calibrated and validated based on runoff measurements at gauging stations using meteorological observation data. According to the results of numerical experiments, the relative change in river runoff in European Russia increases from north to south and from east to west under global warming of 1.5 to 2 °C. As a result, hydrological systems in milder climate were found to be more vulnerable to climate change. The assessment of flow anomalies in European Russia under the selected climate scenarios revealed the following general features: winter runoff in arctic rivers would increase, spring melt runoff in the Northern Dvina and Don would decrease, and summer–autumn runoff in all studied rivers would decrease to varying degrees. The most negative runoff anomalies are characterized in the southwestern part of the Northern Dvina basin, the middle part of the Don basin, and the lowland part of the Kuban basin, whereas positive runoff anomalies are characterized in the northern and eastern parts of the Pechora basin. Global warming of 1.5 to 2 °C would have the greatest impact on the rate of reduction of Kuban summer–autumn runoff and Don runoff during the spring flood, as well as the increase in Northern Dvina and Pechora winter runoff.