Oxygen regime of rivers in the area of sources of economic impact according to long-term monitoring of the Russian meteorological service

The results of long-term observations of the hydrochemical service of the Russian Meteorological Service on the content of dissolved oxygen in the rivers of Russia are considered. Data on the basins of the Amur, Lena, Ob, Volga for 1988-2007 is analyzed. We compared the average monthly oxygen concentrations above and below the sources of exposure – cities, large industrial enterprises – in total, about 100 paired sections were used. The study showed that in about half of these river sections, sometimes (in 14.8 % of cases) small changes in oxygen concentration (6.5-8.3 %) are observed. Wherein, both a decrease and an increase in oxygen concentration can occur below the sources of anthropogenic impact. The latter is typical for winter time, when the flow of heated wastewater into the river leads to formation of an air-hole and the flow of oxygen from the atmosphere into the water. Small rivers in cities experience the greatest stress; however, in general, for all the rivers under consideration, the anthropogenic change in the oxygen regime of the rivers is small and does not significantly affect the sustainability of the development of the territories.