AGRICULTURAL DETERMINANTS OF BIOGENIC POLLUTION OF SURFACE WATERS IN THE DNIPRO RIVER BASIN

Abstract

The necessity of conducting research on the impact of sources of pollution of the Dnipro River depending on their impact is determined. It has been established that the Dnipro River basin is a multi-sectoral complex that covers 48% of the territory of Ukraine and accumulates 80% of water resources. It is noted that the Dnipro River basin has a high natural and socio-economic value, as it meets the drinking needs of 70% of the population of Ukraine. It is established that the sources of water pollution are industrial complexes, agriculture, and urban agglomerations. It is proved that deforestation, intensification of agriculture, hydromelioration, the functioning of the Dnipro reservoirs cascade, and intensive use of water resources are the causes of the Dnipro River basin destruction. It has been determined that agricultural development of the catchment areas has caused soil erosion, which is the most important mechanism of substance migration on the earth's surface, causing up to 17 billion tons of mineral particles and 3.5 billion tons of dissolved substances to enter the seas, oceans and internal runoff zones annually. It is established that high concentrations of mineral particles in surface runoff reduce water quality, which requires additional costs for their treatment, repair of the water supply network, and restoration of irrigation networks. The article has calculated the zonal hazard of nutrient pollution of surface waters within the multi-level sub-basins of the transboundary Dnipro River, which is a consequence of soil-erosion processes. It is established that the sub-basins located in the mixed forest zone or the upper part of the transboundary river Dnipro have the lowest potential for diffuse pollution by suspended solids. It is proved that in order to assess the degree of danger of soil-erosion pollution of water bodies with phosphorus, it is necessary to establish “ecologically limiting” values of the actual concentration. It is proved that the river sub-basins of the Lower Dnipro River, located in the steppe zone, are potentially dangerous in accordance with the indicators of dissolved phosphorus concentration in the waters. The necessity of developing adaptive landscape erosion control projects with elements of soil protection agriculture is determined.