Changes in river water resources of the Russian Federation's economic regions forecasted based on the CMIP5 runoff data

Abstract

The article presents predictive estimates of changes in river water resources in eleven economic regions of the Russian Federation for the period of 2030 and 2050 based on the use of river runoff data of the atmospheric and ocean general circulation models (AOGCM) of the CMIP5 project. An overview of the design schemes of the AOGCM river runoff used in the research is made. The methodology uses an ensemble approach. The predictive estimates were carried out for two forecast periods 2021-2040 and 2041-2060 in relation to the period 1981-2000, which was chosen as the base one. The calculations were made on the basis of an ensemble of 24 selected models for both the moderately aggressive RCP4.5 scenario and the “hard” RCP8.5 scenario. The results obtained were averaged over 20-year periods and compared with the corresponding values for the period 1981-2000. According to the results obtained, in the coming decades there is no reason to expect any significant changes in river flow as a result of climate change. For most of the country's territory, a slight increase in annual runoff is most likely, which is within the limits of its natural variability. The most abundant river water resources will be the Asian part of the Russian Federation and the adjacent eastern part of the European territory of Russia. The most problematic from the point of view of water resources provision will be the Central Black Earth, North Caucasus and Volga economic regions. There will be more water in those regions where it is sufficient, and less where it is most needed. It should be noted that the technique presented in this article is considered by the authors primarily as one of the alternative forecasting methods that must be used in conjunction with other accepted methods. However, given the continuous process of improving the AOGCMs, as well as the quality of the information they provide, this approach should be considered as one of the most promising.