Assessing dynamics of the environmental state of the Siversky Donets’ basin within Kharkiv region

The purpose of this article is determining the assessment of the ecological state of the Siversky Donets basin, its changes within Kharkiv region for the period 1991-2020. Basic material. The topic of climate change and, in particular, its impact on various natural components and the state of the territory as a whole is one of the leading topics of modern science, as the problem is global in nature and has not bypassed Ukraine. For the last decades, Ukrainian scientists have actively studied climate changes, and currently, at the all-Ukrainian level, the impact of these changes on the state of natural complexes and natural components is more than sufficiently covered. This study is of a regional nature, and does not even cover the entire Kharkiv region, but only a large part of it - the Siversky Donets’ basin. It is important to see how climatic changes, changes in the water regime and ecological indicators occur precisely on the example of this basin, taking into account the recommendations of the European Water directive of 2003 regarding the need to implement the basin principle both in the management of water resources and in the study of watercourses. The Siversky Donets’ is the longest river in Kharkiv region and one of the longest in Ukraine. It plays an important role in the water supply of the second most populous city in Ukraine - Kharkiv. The ecological state of the territory is a complex and multi-valued indicator, illustrating a set of indicators of natural components’ state at a certain point of time, or during a certain period. In this work, we consider the ecological state from the point of view of dynamics, that is, a period of 30 years - from 1991 to 2020. The basis for this study was the data of the Kharkiv Regional Center for Hydrometeorology of the State Emergency Service of Ukraine, as well as the data from space cameras and the Regional Office of Water Resources in Kharkiv region. The main task of the study was to form a methodology for calculating the dynamics of the ecological state of the Siversky Donets’ basin within Kharkiv region by calculating the integrated indicator of the dynamics of the ecological state (IPDES). The preceding stage is a statistical analysis of the dynamics of a number of meteorological, hydrological and environmental indicators during 1991-2020, comparing them with the previous period - 1961-1990, which is the old climatic norm according to the recommendations of the World Meteorological Organization, while the period of 1991 -2020 is the new climate norm. Conclusions and further research. The conducted research allowed the authors to develop a series of cartographic works, describing the nature of climatological, hydrological, and ecological changes in the studied territory. The results of statistical data processing made it possible to identify trend lines in the changes of the involved indicators. The authors created a method for calculating the dynamics of the ecological state for this territory as well. Considering all the achievements of this work, it is promising to expand the studied territory to the size of the entire Kharkiv region, as well as to deepen the prognostic component of the study, using several options for creating scenarios for the future course of climatological, hydrological and ecological parameters.