Recent and future trends of river runoff in the North-West Russia

The research is devoted to the identification of the patterns in spatio-temporal variability of river runoff characteristics in the North-West Russia. Based on long-term observation series, trends in the runoff characteristics were calculated as well as the patterns of their spatial variability were analyzed.

Within the framework of the work, the river runoff characteristics for 3 long-term periods were analyzed: the previous (before 1966), modern (1966-2019) and future periods (2022-2099).

The results of our study showed increase amount of cases with maximum runoff rainfall flood being higher than spring runoff from the end of 1980s.Estimates on expected changes in the hydrological regime under the implementation of RCP 2.6, 6.0 and 8.5 scenarios are presented. The most significant changes were detected in winter runoff and maximum spring and rainfall runoff. It is shown that an increase in winter runoff should be expected for the study area, as well as a decrease in the maximum water discharge of the spring flood. At the same time, according to scenarios 6.0 and 8.5, by the end of the century, the maximum annual discharge is likely to be observed during the period of rainfall floods.