Ecological Assessment of Quality of Surface Water of Small and Medium Rivers of Poltava Region

Abstract

Purpose. Environmental assessment of the quality of surface water of small and medium rivers of the Poltava region, in particular: medium rivers – Psel, Vorskla, Merla and five small rivers –Govtva, Grun, Kolomak, Poluzorie, Tashan. Methods. Field, atomic absorption spectrophotometry, cluster analysis. Results. In accordance with the quality standard for surface water of cultural and household purposes, all indicators for medium-sized rivers are within the normal range. There was an excess of zinc in the waters of small rivers - Grun, Tashyas and Poluzorie. The low content of soluble oxygen does not meet the norm. When comparing values with the norm of quality of water for reservoirs of fishery management, excess BOD-5 for the Vorskla and Psel rivers is defined; the content of ammonia and nitrites significantly exceeded the normative value for the river Vorskla,  Psel, Merla. The excess of surfactants for medium rivers is determined. The river Vorskla is mostly polluted with cupper; the Psel river – with zinc and iron, in water from  the Gotvva, Tashan, Poluzorie and Grun rivers we have identified exceeding BOD-5. Regarding the water-soluble nitrogen compounds, only the nitrogen content corresponds to the normative value. The greatest pollution with ammonia is observed for the Govtva and Kolomak rivers. Excess of MAC on the content of nitrites was identified for the Kolomak river. As a result of the cluster analysis of the river, the degree and nature of pollution of surface water are grouped into three main groups: the first is the Kolomak river, the second one is the Merla,  Psel, Grun, Vorskla rivers, the third one is the Tashan, Poluzorie and Govtva rivers. In the future, the results can serve as a tool for regulation, monitoring and solution of pollution problems. Conclusions. Small rivers of Poltava region are under considerable anthropogenic impact, their ecological status is estimated as ecological regression. Therefore, priority attention should be paid to improving the ecological status of small rivers in the Poltava region and implementation of the proposed nature conservation measures.