A System of Models for Studying the Impact of Hydropower Plants Planned in Mongolia on the Hydrological Regime of the Russian Part of the Selenga River Basin

The paper describes models designed to study the impact of hydropower plants (HPPs) planned in Mongolia on the hydrological regime of the Russian part of the Selenga river and Lake Baikal, considering various hydrological conditions and utilizing available technical information on the HPP projects. The developed models include software components for selecting an optimal dam site when precise coordinates are unavailable; constructing reservoir configurations and bathymetric curves demonstrating the reservoir water level-volume-area relationships; preparing hydrological statistics of water inflow into the planned reservoir by correlating meteorological indicators with flow; modeling HPP operating conditions based on different criteria. The primary object of this study is the Egiin Gol HPP on the Eg river, a left tributary of the Selenga river. Mongolia is planning to begin its construction in the coming years. The produced models assess the potential impact of the Egiin Gol HPP reservoir filling and operation on hydrological regimes across various water periods in the downstream pool, along its entire length from the HPP dam to the Selenga river inflow into Lake Baikal. The findings from the modeling serve as the basis for further research into the possible impact of the HPPs planned in Mongolia on the ecosystems of the Selenga river and Lake Baikal.