Оцінювання екологічного стану водних екосистем басейну Західного Бугу

In the modern conditions of the development of the economy of Ukraine, research in the field of analysis and forecasting of the quality of surface waters and their evaluation from an ecological point of view is necessary. The qualitative state of surface water and its assessment must be taken into account in water supply, land reclamation, in communal, agricultural and fisheries, production of industrial products, recreation, sanatorium-resort development, etc.The purpose of the study is to assess the ecological state of the surface water bodies of the Western Bug basin in the territory of the Chervonohrad Territorial Community.In order to assess the degree of exceeding the MPC of the indicators of the quality of water bodies of the surface waters of the Chervonohrad TC in 2018-2022, the values of the average annual concentrations of pollutants were compared with their MPC. The water pollution index was calculated, which made it possible to compare the water quality of various water bodies with each other, regardless of the presence of various pollutants, and to identify the trend of changes in water quality over time.According to some indicators of the quality of surface water (content of ammonium salts, nitrites, dissolved oxygen, BOD5 indicator), the waters of the Western Bug and Rata rivers in 2018-2022 do not meet the standards. Most of the considered indicators during 2018-2022 in the control body of the Western Bug River have a general upward trend, which indicates the instability of the ecological situation of the basin. For the Rata River, this trend is not so pronounced. In the Western Bug River in 2018-2019, the state of water is assessed as III quality class and the water is assessed as moderately polluted, but in 2020, a sharp deterioration of water quality to IV class – polluted water is recorded. By 2021, a slight decrease in the water pollution index is recorded, but everything remains at the same IV water quality class as in 2022. In the Rata River in 2018-2019, the water quality is rated as II quality class, the water is clean, but in 2020-2022, the water pollution index increases to III quality class, the water is moderately polluted. The obtained results indicate the need to apply nature protection measures to preserve and improve the ecological condition of the river network.