WATER BALANCE AND ECOLOGICAL CONDITIONS OF THE RYBINSK RESERVOIR IN THE EXTREMELY HIGH-WATER YEAR OF 2017

Abstract

This study analyzes the inflow, runoff and water level of the Rybinsk Reservoir during the extremely highwater year of 2017. It was the second-highest on record high-water year in the reservoir basin during the whole period of the reservoir operation. The total annual inflow to the reservoir significantly exceeded its long-term average and amounted to 52,148 km3. Such an increase in the inflow is due to rising air temperatures in winter time under the increasing influence of global warming and high rainfall. To characterize ecological conditions in the reservoir we use data on its water balance, mean ten-day period water temperature in May-October provided by Yaroslavl Center for Hydrometeorology and Environmental Monitoring and materials from six hydrological and hydrobiological expeditions conducted by researchers from the Institute for Biology of Inland Waters RAS (IBIW RAS) in May-October, 2017. During the expeditions to the reservoir, integrated hydrological, hydrochemical and hydrobiological investigations were conducted at standard stations. These studies have been carried out by IBIW researchers since 1962 to monitor the dynamics of ecological conditions of the waterbody.