Possible causes of natural water level variations in the Kosin Lakes in the 20th-21st century - natural and anthropogenic

Fluctuations level of Kosinsky lakes in Moscow are of great importance not only for the comfortable living of peoples and for the functioning of one of the city’s popular recreational areas. In addition, it is important for the preservation of all unique ecosystem of the protected area. The decrease in the level of lakes during the 20th century, combined with their pollution, repeatedly led to their eutrophication and fish kill. The aim of the work was to establish the relationship the water level in the Kosinsky lakes (during the observation period) the amount of precipitation and economic activities related to drainage. The null hypothesis: the reason for the modern swallowing of the Svyatoe Lake is not so much climate change as anthropogenic activity. The article presents data on fluctuations in the level of lake-type water bodies in the Kosino-Ukhtomsky district of Moscow, for the period 1924-2021, and an assessment of the impact of them modern anthropogenic processes. The work is based on the results of both the authors’ own field research (geodetic survey in the Kosnsky Three Lakes area in 2006-2021) and archival data from the Kosinskaya biological station and other organizations. It shown that the changing level of the Holy Lake in the last decade cannot explained only by meteorological phenomena (precipitation). The significant role of hydrotechnical measures in regulating the level of lakes Beloe and Chernoye has confirmed.