ASSESSMENT OF THE ECOLOGICAL STATE OF THE SURFACE WATER CONDITION OF THE OPIR RIVER

Abstract

Russian aggressors are increasingly targeting Ukraine's critical infrastructure, leaving the civilian population without electricity, heating and central water supply. Military operations force the population to migrate and stay, mainly in the western regions of Ukraine, increasing the anthropogenic load. Therefore, constant monitoring of biological resources is one of the mandatory and key tasks that allow monitoring the ecological state of existing water ecosystems. The best indicator of the ecological state of the environment is small rivers near settlements, which quickly respond to changes in anthropogenic loads. The purpose of the study: determination of the ecological state of the Opir River basin within the area of the village. Oporets (from the source of the river) to the village. Grebeniv According to hydrochemical indicators, the surface waters of the Opir River within the Oporets – Grebeniv village section can be considered satisfactory. Surface waters are neutral, weakly mineralized, with a hydrocarbonate-calcium composition, which is generally characteristic of this region. Along the course of the river, no noticeable changes in the composition of the waters were observed. In almost all samples, an increased content of ammonium ions was recorded, which indicates that domestic sewage has entered the river. The waters are sufficiently saturated with oxygen. Low concentrations of some components are probably due to the relatively long length of the Opir River and its tributary, mountainous terrain and sufficient self-purification capacity. The quality of water in the sample taken from the Opir River near the village is considered to be the best. Oporets, which can be considered background, is the worst – samples taken from the Slavska River. The average indicators of water quality and ecological condition of the Opir River in the studied area are as follows: according to the water pollution index – class II, moderately clean, 2-3 categories (clean – moderately polluted); according to the water pollution level index – slightly polluted; according to the index of hydro-ecological potential – alarming (stressed) state of the water ecosystem, satisfactory category of natural and man-made safety of the water ecosystem. The ability of the aquatic ecosystem to self-purify is average, and the overall assessment is adaptation stress. The use of the ecosystem approach to the analysis of the quality of surface water will allow to assess the ecological risk, which takes into account the ability of the water ecosystem to self-restore, the duration and distance from the source of anthropogenic pressure.