Study of fragmentation impact of small riverbeds by artificial waters on the quality of water resources

Abstract

Purpose. Study the spatial distribution of artificial reservoirs in the Dnipropetrovsk region and fragmentation impact of small riverbeds on changes in the quality of water resources. Methodology. Field studies on the current state of small river basins were carried out, rivers were selected on the principle of different geographical location and levels of anthropogenic impact. Analytical laboratory studies of water salt composition and methods of mathematical analysis were used to establish the dependence coefficients of water mineralization level and fragmentation of the river basin on the water flow regulation. Findings. The structure of the spatial distribution of artificial reservoirs in the administrative districts of the region and their hydrological characteristics are generalized. It is shown that small volumes of accumulated water in relation to the total area of reservoirs are the cause of intensive heating and evaporation of water. Due to this, the hydrochemical parameters of water are worsen, which affects the environmentally safe water use. It was found that the level of mineralization, the content of sulphates and chlorides exceed the maximum acceptable concentrations in all studied rivers. There is a tendency of deterioration of water quality in the salt block, especially in rivers with significant regulation of artificial reservoirs. In this case, water salinity exceeds the norm by 712 times. Indicators of water mineralization of rivers with fewer ponds and less fragmentation of the river basin exceed the standards by 25 times. Originality. It is determined that among the main factors of anthropogenic impact on the state of aquatic ecosystems is the fragmentation of riverbeds by artificial reservoirs, which turned rivers into cascades of water evaporating ponds. There is a close relationship between the factors of water flow regulation and the level of water mineralization (coefficient of determination R2 =0.62), as well as the coefficient of fragmentation of the river basin (R2 = 0.61). This proves the possibility, in the conditions of research of small rivers, to estimate the degree of change (increase) of water mineralization level by the coefficient of water flow regulation Kw and the coefficient of river fragmentation by the area Practical value. The main directions and ways to normalize the ecological status of watercourses are given. The necessity of systematic study of the current ecological condition of small rivers of Dnipropetrovsk region and their basins is determined.

Study of hydraulic bases of technological fluids circulation

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