SELECTION OF INDICATORS FOR MONITORING SURFACE WATER QUALITY OF PRIPYAT RIVER

Abstract

It is known that the determination of the contribution of individual hydrochemical indicators to the general level of pollution of water objects allows to choose priority indicators of monitoring. This also ensures that the management of water resources is adapted to the specific characteristics of water bodies or their parts. The purpose of this article was to identify the most indicative monitoring indicators for different areas of Pripyat River, based on long-term information on chemical indicators in surface waters of the river. During the researches the database of observations on surface waters of the State Agency of Water Resources of Ukraine was used, during 2005–2021. It was a list of nine hydrochemical indicators. We analysed five parts of the Pripyat River. First, we determined the fluctuations of water quality indicators. Then we compared them with the normative values of the water-consumption category for fish breeding. This showed that the water of the river does not meet the quality standards by such parameters as ammonium-ion (with an over output from 1,4 to 9,5 times), biochemical consumption of oxygen in five days (with an over output from 1,6 to 26,0 times), phosphate-ion (with an over output from 1,6 to 3,8 times) and nitrites-ion (over 2,0 to 19,0 times). We have also established pollution contribution rates for all hydrochemical indicators. According to our results, the priority indicators of surface water quality monitoring of Pripyat River may be those for which the pollution contribution factor exceeded 6%: ammonium-ion, DCO5, suspended substances, sulphate-ion, nitrites-ion, oxygen dissolved and phosphate-ion. Given that the ammonium-ion and DCO5 had the highest coefficient (> 21%), as well as numerous statistically significant relationships with the rest of the hydrochemical indicators, they are recognized by us as the main indicators of monitoring. We believe that the approach proposed by us will facilitate the convenience of choosing the places of sampling and parameters of water quality. As a result, it will form effective decisions when planning management activities to protect water resources within river basins.