ANTHROPOGENIC TRANSFORMATION OF THE LYUTITSA RIVER BASIN

Abstract

The Liutytsia is a typical small river of the Polissya part of the Volyn region. It flows through the territory of Rozhyshche and Kopachivka united territorial communities. The river is 37 km long, with a catchment area of 208 km2, 3.6% forest cover, 1.4% marshland, and 60.5% ploughed. About 10,000 people live within the basin. The territory has long been developed. Agricultural use predominates. Specialisation: growing potatoes, cereals, industrial crops, dairy and meat farming and processing of agricultural products. In the structure of land use in the basin, 87.6% of the land is used for agricultural purposes. All land available for agricultural use has been ploughed and is actively used. Within the basin, the permissible land use limits are exceeded. This contributes to the aggravation of the environmental situation and requires the implementation of measures for the rational use of natural resources and nature protection. 8.8% of the basin's territory is occupied by settlements, industrial, transport, communications, etc. The basin's water resources are also actively used. Most of the water is used for water supply to the population, industry and agriculture. In a year of 95% runoff availability, total water withdrawals exceed 20% of the annual runoff, and irreversible water consumption in the basin is 15%. In the future, runoff shortages may become a problem in low-water years. The frequency of dry years has been increasing recently. The concentration of most chemicals in the river water does not exceed the maximum permissible concentration. The content of ammonium nitrogen exceeds the per capita values by 15.6 times in the first and 2.92 times in the river channel 2, nitrite nitrogen by 1.7 times and 1.91 times, respectively, and total iron by 16 times and 2.4 times. The excessive content of nitrogen compounds is caused by surface runoff from urban areas, fields, farms, and spontaneous solid waste dumps. The area of drained land within the basin is 8,606 thousand hectares, with a land reclamation rate of 41.4%. There are 5 drainage systems within the basin. Soil overdrainage is widespread within the basin's drainage systems, leading to loss of soil cohesion, loss of vegetation cover and deflation. With distance from the drainage network, water drainage is worse, there are waterlogged areas, rewetting occurs due to inefficient drainage channels that are silted and overgrown with vegetation. Some reclaimed areas have not been ploughed for many years and are overgrown with selfseeding. Hazardous exogenous processes are occurring within the basin: karst, secondary waterlogging, and siltation of the riverbed. Soils are also undergoing negative changes. Erosion processes are occurring, the depth of the humus horizon is decreasing, and the content of humus and plant nutrients is decreasing. Environmental problems in the basin include: violation of water protection zones, ploughing and rewetting of the floodplain; lack of hydroecological monitoring in the river basin; poor condition of drainage systems; lack of soilprotective technologies for growing crops, violation of recommendations for the use of drained land; illegal landfills in the basin; low forest cover, lack of protected areas within the basin, lack of an effective local ecological network.
 Keywords: river basin, geoecological state of the basin, sources of anthropogenic impact within the basin, anthropogenic transformation of the basin.