Input of Inorganic Matter Into Upper Volga Reservoirs From Shoreline Abrasion

ABSTRACT The study focuses on the investigation of shoreline abrasion processes in the Upper Volga Reservoirs (Gorky, Ivankovo, Rybinsk, Uglich, and Cheboksary) and their impact on water quality. The aim of this work is to estimate the influx of mineral elements (Si, Al, Fe, and Ca) and total nitrogen into the reservoirs through abrasion sediments. The methodology involves analyzing satellite imagery for shoreline identification using the Dynamic World V1 global dataset and delineating eroded areas using QGIS tools alongside data on bank retreat (the length of eroded shorelines and their recession rates). The assessment focuses solely on the soil profile, excluding the influence of abrasion on the parent rock. Soil types adjacent to the eroded shorelines and their elemental composition were obtained from the Unified State Register of Soil Resources of Russia. The results indicate that approximately 673 thousand tons of soil annually enter the reservoir waters due to abrasion. The primary factor contributing to soil loss is the extent of eroding shorelines. In terms of chemical composition, the sediments are dominated by silicon (70%–85%), whereas biogenic elements (phosphorus and nitrogen) play a negligible role in water pollution.