Hydrochemical Characteristics of the Upper Volga Reservoirs in the Low-Water Season of 1997

The results of studies of the Ivankovo, Uglich, Rybinsk, and Gorkii reservoirs are analyzed. The studies involved a wide range of hydrochemical (salt composition, biogenic elements, organic matter, oil products, and heavy metals) and hydrophysical characteristics in the summer low-water period. The concentrations of organic matter and major biogenic elements are shown to decrease downstream along the chain of reservoirs with a respective general decrease in the trophic status. Large built-up areas located downstream of the Rybinsk Hydroelectric Plant are shown to adversely affect the river water quality.[PUBLICATION ABSTRACT]