Abstract
The paper deals with the influence of the hydrological regime of the Charyn River, where the Bestyubinsk reservoir was built in 2012, on the state of floodplain geosystems. The research aims to identify and analyze the impact of regulation of the Charyn River flow reservoir on the state of geosystems. Research tasks include (1) calculating and analyzing the hydrological regime of the Charyn River; (2) identifying the sections of the river floodplain most susceptible to the threat of flooding before and after the construction of the reservoir; (3) compiling comprehensive physical and geographical characteristics of the floodplain geosystems of the Taskarasu Valley subject to frequent flooding. In the analysis of the hydrological regime of the river, we used difference and total integral curves to identify the cycles of fluctuations in the annual runoff. The river runoff was estimated by the change in the parameter of the mean annual runoff for 2004–2018. As a result of the interpretation of satellite images, using the Automated Water Extraction Index integrated with ArcGIS, the most frequently flooded area of the river floodplain for this period was identified. The time and area of flooding were determined. Based on the data obtained, the flooded areas were compared for 2004–2018. The advantages of visual observation using satellite images are the ability to clearly and intelligibly visualize the flooded area and systematically, as quickly as possible, reach the required site coordinates using decoded digital data, which is necessary when studying the functioning of geosystems. To describe the state of the floodplain geosystems most susceptible to flooding, we used the data for many years of field landscape studies. Thus, comprehensive physical and geographical characteristics of the Taskarasu Valley were given.