GEOECOLOGICAL STATE OF THE RIVER OKONKA BASIN AND ITS OPTIMIZATION
Authors: Fesiuk Vasyl , Slusarchuk Andrij 
Published: December 2021

The impact of economic activity on the environment can best be traced in the scale of small river basins. One of such rivers is the Okonka River, which flows through the territory of the former Manevychi (Kamin-Kashyrskyi according to the new administrative-territorial structure) district. Among the environmental problems of the basin, the most acute are: surface water pollution due to runoff from agricultural fields, livestock farms, unauthorized landfills, etc. Improving the geo-ecological condition of the Okonka River basin on the basis of ecologically safe sustainable development is an urgent problem of the territory's development. The Okonka River Basin is one of the least explored regions of the Volyn Region. Materials from the Regional Office of Water Resources in Volyn Oblast, the Department of Ecology and Natural Resources of the Volyn Oblast State Administration, own expeditionary research, cartographic materials, electronic maps (Google Map, OpenStreetMap) and satellite images were used to prepare the publication. Also, more than 20 literature sources and electronic resources, laws and regulations of Ukraine in the field of rational use and protection of water resources were developed. The following methods were used during the research: collection and processing of archival, literary, graphic, cartographic and tabular material, regime quantitative and qualitative observations of river characteristics; field research of channel processes; mathematical and engineering calculations, mathematical modeling, analysis of anthropogenic impact on water resources of the studied region, constructive-geographical method and method of expert assessments. The natural conditions of the basin contribute to the settlement and development of the economy. Particularly favorable are the terrain, climate, inland waters. Within the basin there are 7 objects and territories of the nature reserve fund. The impact of anthropogenic activity on the river basin is quite significant. This is due to intensive agricultural and residential use, the development of drainage reclamation. The level of radiation pollution is assessed as "satisfactory", the use of land resources - "close to normal. The water quality of the Okonka River in the upper line (leak) is assessed by the second class of the third category (water is quite good in quality, quite clean in purity). The environmental index is 2.92. Environmental protection measures are proposed to improve the geoecological condition of the river basin. The complex of environmental protection measures should include: development of a local eco-network; creation of new and expansion of the network of existing nature reserves; improvement of the situation with waste management, elimination of spontaneous dumps; monitoring of soils to protect them from degradation and pollution; monitoring of surface waters in order to protect them from depletion and pollution; an inventory of drainage systems in order to establish the feasibility of further use in agricultural separate areas, the allocation of parts of the drainage systems that can be renaturalized in the future; prevention of peat and forest fires.

Key words: river, river basin, geological condition of the river basin, geographical features of the basin, ecological assessment of river water quality, measures to improve the geoecological condition of the basin.