Statistical analysis of water quality indicators in the Tisa River’s transboundary section

In today's conditions, when river basin systems are undergoing anthropogenic transformation and considering the multifactorial impact of economic activity on the environment, there is a need for a comprehensive analysis of surface water quality. Since river waters are closely connected with the catchment area, they serve as indicators of the geo-environmental state of the entire basin system. When selecting the research object – a transboundary section of the Tisa in Zakarpattia Oblast (Dilove – Tyachiv) – not only natural factors that shape river water quality but also various anthropogenic pressures were considered. The Tisa basin in the Rakhiv district is of great ecological, economic and transboundary significance. The study aims to assess the water quality of the Tisa's transboundary section from Dilove to Tyachiv. The objectives are to substantiate the scientific basis for environmental studies of surface waters, analyse the hydrochemical parameters of water quality in the transboundary section of the Tisa, based on the stock materials of the Tisa Basin's water resources management, determine the quality of river waters in the section of the Tisa, using the methodology for assessing water quality by a complex indicator – the hydrochemical water pollution index; identifying natural and anthropogenic factors that affect the physical and chemical indicators of water quality; developing recommendations for improving water quality within the study area. The study applies a systematic approach to analysing the water quality of the Tisa, which aims to optimise nature management and increase the effectiveness of water protection measures. General scientific methods, such as retrospective analysis, systematic and structural approach, and evaluation methods, like special methods, such as mathematical and statistical analysis, semi-stationary observations, and cartographic studies, were used. The main tool used in the study is the methodology for assessing water quality based on the hydrochemical water pollution index.