ВДОСКОНАЛЕННЯ МЕТОДИКИ КОМПЛЕКСНОЇ ОЦІНКИ ЕКОЛОГІЧНОГО СТАНУ ПОВЕРХНЕВОГО ВОДНОГО ОБ’ЄКТА (НА ПРИКЛАДІ СУББАСЕЙНУ СЕРЕДНЬОГО ДНІПРА)

The article discusses the principles of water resources management within river basins in Ukraine and the world. The principle of international water resources management in transboundary river basins is based on an integrated approach that involves considering the entire basin as a single management and planning system. The purpose of the study is Increasing the level of reliability of the assessment of the ecological state of a surface water body by taking into account the impact of an upstream tributary on a downstream tributary within the sub-basin on the change in the ecological state of the main waterway of Ukraine. The scientific novelty lies in the fact that the methodology for a comprehensive assessment of the ecological state of a surface water body has been further developed, which allows them to be ranked by their ability to transfer pollutants within a subbasin. An algorithm of management actions for the implementation of the basin principle of water resources management is proposed, based on an integrated approach to assessing the ecological status of a surface water body subbasin by taking into account the impact of the left tributaries of the Dnipro River on the ecological status of the main waterway, which involves the sequential implementation of the following steps: collection and processing of the data obtained by each involved structure, determination of the predicted value of the impact of upstream tributaries on downstream tributaries of the main river within the subbasin, etc. The units involved in the developed algorithm, either independently or in cooperation with another organization, should immediately take the necessary measures to inspect and clarify the situation, to eliminate the consequences and control the situation that has arisen on the water body. Recommendations have been developed to improve the methodology for assessing the ecological status of a surface water body based on an algorithm of management actions, using a mathematical model for predicting changes in the ecological status of the main waterway within the basin, by taking into account the mutual influence of the left tributaries of the Dnipro sub-basins for prompt response to natural and man-made emergencies.