Iarochevitch O. Hydromorphological assessment of ecological status for rivers in Tisza basin within Ukraine.

The thesis represents the study of hydromorphological parameters of rivers of Ukrainian part of the Tisza basin and their assessment as a part of ecological status determination using the proposed methodology. The thesis presents key elements of hydromorphological river assessment, their definition and order of implementation. The main hydrographic characteristics of Ukrainian part of Tisza basin are clarified, namely area of the basin, length of the river, and zoning of its catchment. Identification of water bodies in the Tisza basin using the different categories (rivers, lakes and artificial water bodies) is conducted. For the first time, typology of the Tisza basin is done, using size and altitude of the basin, geology and average size of the riverbed sediments. As a result, 12 abiotic river types were identified. Methodology of hydromorphological river assessment is proposed, which allows using quantitative criteria to calculate a hydromorphological index and status of a river at representative sites and in general. It includes several new statements to take into account natural specifics of rivers in Ukrainian part of Tisza basin.