Phosphorus runoff from catchment areas of the Volga region

Based on the results of hydrological and hydrochemical observations, phosphorus runoff from the catchment areas of the rivers of the Volga region, located in different climatic conditions and experiencing different anthropogenic load from point and diffuse sources of pollution, is estimated. Assessment of phosphorus runoff is due to the need to solve the problem of anthropogenic eutrophication of large reservoirs of the Middle and Lower Volga. The main catchment areas of the Samara, SOK, Syzranka, Chapaevka, Maly Irgiz and Chagra rivers flowing into the Saratov reservoir were selected as objects of research. It was found that the highest average annual phosphorus flow modulus is typical for the catchment area of the Syzranka river, located in the forest-steppe province of the Volga upland, and is 521.0 µg/(c km2). The lowest average annual phosphorus flow modulus is typical for the Chagra river, located in the steppe province of the Lowland and Syrtic Zavolzhye, and is 180.65 µg/(c km2). The calculated value of phosphorus runoff from catchment areas of rivers includes natural and anthropogenic components.