Water Chemical Composition of the Selenga River in High Water Level Period

The ecosystem of the lake Baikal is one of the oldest freshwater reservoirs on the planet, where the largest available reserves are concentrated. The purpose of this study is to study the chemical composition of the surface waters of the Selenga River and its main tributaries in high water level period. The flow of river water plays an important role in the overall balance of substances entering the lake, since it is the main element of the incoming part of the chemical balance of the lake. The Selenga River is the main tributary of Lake Baikal, in the basin of which, unlike other tributaries, a large number of industrial, agricultural, processing enterprises, settlements and cities are concentrated. This article presents the results of the analysis of samples of surface waters of the Selenga River and its main tributaries taken in 2018. In 2018, the flow of the Selenga River after a long low-water period was close to the average annual one, which caused a significant decrease in the concentrations of components, while the relative composition of the main ions remained stable in all periods. Our study shows that the chemical composition of the water of the Selenga River depends on the fluctuations in water content.