LVIV UNITED TERRITORIAL COMMUNITY RIVER BASIN STRUCTURE

Abstract

The main hydrographic, hydromorphological and hydroecological features of the Lviv United Territorial Community (UTC) have been analyzed, in particular: a) the location of the city of Lviv on the Main European Watershed; b) transformation of surface water runoff as a result of the general sewage network and reclamation systems functioning, industrial peat extraction, residential and industrial construction. These features compose the delimitation of surface water bodies, which had been provided by the guidelines of the Water Framework Di-rective of the European Union (WFD). As a result of progressive urban expansion, the area of the territorial community of the city constantly increased from 0.5 km2 (end of the 14th century) to 31.66 km2 (end of the 19th century), 66.6 km2 (middle of the 20th century), 182 km2 (second half of the 20th century), 311.4 km2 in 2020. Correspondingly, the area ratio of the Baltic and Black Sea peripheral drainage areas changed. The assessment of the surface water delimitation scheme body, proposed by the State Water Agency and highlighted on the geoportal “Water Resources of Ukraine”, was carried out. It has been established that the main shortcoming of this scheme is non-compliance with the principle of coherence of surface water bodies to catchment areas provided for by the EU WFD. By means of computer processing of the high-resolution digital elevation model (DEM) of Lviv (UTC), in an automated mode, a watershed network of surface water coherent bodies has been built. According to the assessment of the surface runoff transformation degree, the identified massifs are identified by categories: natural, significantly changed, artificial. The territory of the city of Lviv, which is covered by a general sewage network, is classified as an "artificial body of surface water". It is assigned to the Vistula basin area, despite the fact that 14.95 km2 of the massif is located in the topographic catchment of the Dniester. Watersheds that include reclamation systems are classified as "significantly changed bodies of surface water" According to the assessment of the surface runoff transformation degree, the identified bodies have been identified by categories: natural, significantly changed, artificial. The main morphometric indicators of the watersheds of the proposed surface water bodies have been determined, in particular the following: a) "water catchment length"; b) "average width of the catchment"; c) "water catchment asymmetry coefficient; c) "coefficient of compactness of the catchment". The correct definition of river basins structure is the first necessary step in implementing the provisions of the EU WFD into the practice of water resources management in Ukraine. Further actions provided in River Basin Management plans depend on this step Key words: river basin; surface water; body of surface water; surface runoff; transformation of flow.