Long-term and seasonal water level fluctuations of the Rybinsk Reservoir and their role in the functioning of its ecosystem

Seasonal and long-term variability of the Rybinsk Reservoir level regime over the period of its operation was analyzed. Changes in the level regime at different phases of water content were shown together with the data on mean monthly and extreme level values and the rates of the reservoir filling and drawdown. The level regime impact on the functioning of individual components of the reservoir ecosystem was discussed. Due consideration was given to the assessment of changes in the reservoir environmental situation under the condition of the normal impounded water level drop by 1 m.