Improvement of the methodology for comprehensive assessment of the ecological status of surface water bodies

The principle of international water management in transboundary river basins is that water-related issues should be addressed at the basin level as a whole, with the aim of preventing critical changes within the basin by any single country acting unilaterally.The principles of water resources management in the European Union include the precautionary principle, a high level of protection, preventive measures, the polluter pays principle, international cooperation, etc. [1, 2].The Rhine River is a good example of compliance with these principles.It flows through nine countries and has a total length of 1,320 kilometers.The International Commission for the Protection of the Rhine (ICPR) was established to protect the Rhine.The Rhine 2020 program includes the following provisions: reducing damage by 25% by 2020; improving flood awareness and warning systems; maintaining and strengthening dams (27 hydroelectric power plants have been built along the river); and compiling flood risk maps (for spatial planners).Based on this program, Rhine 2040 was created in February 2020 [4].The goal of the program is to create and implement a process for managing the Rhine River basin in response to the effects of climate change.Rhine 2040 aims to ensure the self-cleaning capacity of water, increase biodiversity, and facilitate the exchange of approaches, methods, experience, and scientific research on adaptation to climate change.Water resources management within Ukraine's river basin is carried out in accordance with the basin management principle under the Water Code of Ukraine.To ensure effective management of the environmental safety of water resources, basin councils were established on the basis of Article 13 3 of the Water Code of Ukraine [3].