ON SEASONAL CHANGES OF THE QUALITY OF WATER OF THE IZHEVSK POND
The article discusses the features of the seasonal dynamics of the main water quality indicators of the Izhevsk pond for a long-term period. The problem of a sharp change during a year of some ingredients of the chemical composition of pond water is extremely urgent, since the reservoir is one of the main sources of drinking water supply in Izhevsk. Since the high content of organic matter and the development of eutrophication processes are relevant for the waters of this reservoir, the issues of the variability of the oxidizability and chromaticity of water, as well as the dynamics of the phytoplankton abundance, are described in more detail. In the course of the study, deviations from the natural intraspecific course in the content of the pond of mineral salts and some biogenic compounds were revealed in the water. The nature of these deviations signifies a significant impact on these indicators of the catchment area that supplies chlorides, sulphates, and mineral nitrogen compounds to the body of water with surface runoff from unorganized pollution sources. At the same time, there was a positive trend in the dynamics of the BOD of water, which had a more natural course during the considered time than in the late 90's and early 2000's.