Comprehensive Assessment of Long-period Variation Characteristics of Water Quality in the Xiangjiang River Basin based on Mann-Kendall Test

Water is essential for the sustenance of all life forms, comprehensive and accurate assessment of water environmental quality is of great significance to promote the prevention and control measures of water pollution. By collecting the water quality monitoring data of 34 monitoring points in Xiangjiang River Basin for more than 10 years published by China Environmental Monitoring Station, Environmental Professional Knowledge Service System and Hunan Provincial Department of Ecological Environment, the water quality index data set was constructed. After data cleaning, using Single Factor method, Comprehensive Water Quality Index Identification method, combined with statistical method and Mann-Kendall Trend Test and other technical methods, the water quality change of Xiangjiang River from 2013 to 2023 was analyzed and studied. The results showed that due to proper water environment management, water quality indexes such as NH<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>-N showed a downward trend year by year, and the Class I water standard was maintained after 2019. It showed that the water environment management in Xiangjiang River basin has achieved remarkable results in the improvement of water quality, water resources management and social participation, and had realized a virtuous cycle of economic development and ecological environmental protection.