为全面了解丹江库区近年来的水环境状况，基于 11 个监测断面 2015—2020 年的水质监测数据，使用 Mann- Kendall（M-K）趋势检验和 Pearson 相关分析等多元数据分析方法，结合改进的综合水质指数（water?quality?index， WQI）和综合营养状态指数（trophic?level?index，TLI），探究丹江库区自南水北调中线工程通水以来水质的时空分布 特征和影响因素。结果表明：2015—2020 年，丹江库区水质指标呈现明显的季节变化和空间分布差异特征，水体 污染以氮、磷为主，质量浓度较高的区域主要集中在库区北侧；库区整体上水质为“良”且处于中营养状态，支流 水质相比库区污染较为严重，汛期水质差于非汛期，但年际间呈现逐渐改善的趋势；主要受控于降雨和人类活动 等因素影响，由工业、生活、农业等导致的点源、面源污染负荷显著，因此未来在水源地水环境保护治理过程中， 应加大对老鹳河、丹江等重点支流的污染治理，控制面源污染的排放。

In 2012, the State Council of China issued an opinion on the implementation of the strictest water resources management system. It aims to effectively strengthen water pollution prevention and control, improve the quality of the water environment in key river basins, and prevent the eutrophication of rivers and lakes. Danjiangkou Reservoir, as the most important water storage and water supply facility in China, plays a crucial role in the supply of safe water. In recent years, due to the expansion of Danjiangkou Reservoir, the rise of water level, the increase of water storage, and the increase of exogenous nutrient salt content, coupled with the fluctuation of water level, nutrient salt, and other hydrological and environmental conditions brought by the water transfer and water supply of Danjiangkou Reservoir, all will increase the potential risk of reservoir eutrophication. Therefore, strengthening the monitoring and early warning of the water environment is an urgent need for the water safety of the residents in the receiving area and the effective performance of the project.To comprehensively understand the water environment status based on data from 11 monitoring sections from 2015 to 2020, with the help of multivariate data analysis methods such as Mann-Kendall (M-K) trend test, multiple linear stepwise regression analysis, and Pearson correlation analysis, and combined with the improved integrated water quality index (WQI) and integrated trophic level index (TLI), the spatial and temporal distribution patterns and influencing factors of water quality in the Danjiang Reservoir area since the commissioning of the South-North Water Transfer Central Project were explored. According to the research results, from 2015 to 2020, water quality indicators showed obvious seasonal changes and spatial distribution differences in the Danjiang Reservoir area. Water pollution was mainly nitrogen and phosphorus, and the mass concentration of higher areas was mainly on the northern side of the reservoir. The overall water quality in the reservoir area was "good" and in the mesotrophic state, tributary water quality was more seriously polluted than the reservoir area, and the water quality in flood season was worse than that in non-flood season. NH3-N, DO, CODMn, TN and BOD5 were the five key indicators that contribute the most to the water quality of Danku. It is mainly controlled by factors such as rainfall and human activities, and the point and non-point source pollution loads caused by life, industrial and agricultural activities.At this stage, nitrogen and phosphorus are the main sources of pollution in the Danku. In the future, during the treatment of water environment protection in water sources, pollution control of key tributaries such as the Laoguan River and the Danjiang River should be increased to control the discharge of non-point source pollution and provide reference in terms of water dispatch for the South-North Water Transfer Central Project.