On the impact of the development of the Verkhnyaya Sukhona river catchment area (the Vologda region) on the chemical composition of the waters in its tributaries

The aim of the investigation was to study the influence of anthropogenic burden on the catchment areas of the rivers in Vologda Region and to establish the dependence of the chemical composition of water on pollution sources in the rivers of the Verkhnyaya Sukhona basin. In the catchment areas hydro chemical samples were taken, population density was calculated as well as the automated and visual interpretation of the main elements of the landscape was carried out. At that, forests, populated areas, farmlands and other territories changed by economic activities were identified. An increase in the pollutants concentration in the catchment areas on drawing near the regional center was detected. The development of the catchment areas varies depending on the landscape pattern and on the proximity to the city of Vologda. The population density and the relative area of settlements and farmlands increase while approaching to the city, at the same time the ratio of forests decreases. The positive correlation dependence between the phosphate content and the relative size of farmlands was shown. The main source of pollutants in the catchment areas of the Verkhnyaya Sukhona basin is the presence of settlements and high population density. Under such conditions, high concentration of sodium, chlorine, nitrogen-containing compounds as well as permanganate oxidizability are observed in water.