Modeling of integrated indicators of the environmental state of surface water

Abstract

The problems of deterioration of the ecological state of surface sources of drinking water supply especially concern water reservoirs since they are created for accumulation of water reserves. Biochemical oxygen demand and dissolved oxygen are integral indicators that characterize ecological state of a water body on the whole. Based on retrospective observational data for 2010–2014, the author analyzed dynamics of indicators of BOD and of dissolved oxygen in the Chervonooskil reservoir (Ukraine). The tendencies towards improving oxygen regime of the reservoir were detected: an increase in concentration of dissolved oxygen and a decrease in BOD by average annual indicators. This is explained by a decrease in anthropogenic load on the basin of the water body due to economic decline, which is a consequence of unfavorable political situation in the country. Authors determined coefficients of biochemical oxidation of organic substances of the Streeter-Phelps model for the water reservoir. Given the influence of temperature on oxygen solubility and on the rate of biochemical processes, calculation of parameters k1 and k2 was performed for each month of the year. Correlation coefficient between the modeled and empirical values of biochemical oxygen demand is 0.86, which can be considered acceptable for such research