长江流域典型城市水生态环境特征解析及综合整治对策

以长江流域典型城市为研究对象，估算长江干流、主要支流和通江湖城市COD、氨氮、TN和TP污染排放负荷，梳理典型城市水环境质量、水生态、水资源和水安全特征。结果表明，长江流域内56个城市COD、氨氮、TN、TP的排放量分别为193.78万、15.57万、31.01万和2.18万t/a，流域内大部分城市主要污染源为城市生活源，但工业源和城市面源不容忽视。近年来，流域内城市面源排放负荷占比升高，部分城市水生态系统遭到破坏，存在水质型和资源型缺水、水资源开发利用不合理、非常规水利用率低等问题，导致部分城市仍存在水生态环境安全风险。在此基础上提出了流域内城市“十四五”时期水生态环境综合整治对策建议。

Analysis of the characteristics of water eco-environment and comprehensive countermeasure for typical cities in the Yangtze River Basin

The discharge loads of COD, NH3-N, TN and TP from typical cities at the mainstream, tributary streams and around the lakes connected with the Yangtze River Basin were evaluated. The characteristics of urban water environment quality, water ecology, water resources and water security of the typical cities were analyzed. The results showed that 1937800, 155700, 310100 and 21800 tons of COD, NH3-N, TN and TP, respectively, were discharged from 56 cities in the Yangtze River Basin for each year. The domestic source was the main pollution source for most cities in the Yangtze River Basin, and the pollution from industry and non-point sources was also nonnegligible. In recent years, the increasing non-point source proportion, the general damage of the urban water ecosystem, the shortage of water due to water quality and resources in some cities, the rough use of water and low utilization of unconventional water sources led to the prominent water ecological risk in these cities in the Yangtze River Basin. Finally, comprehensive countermeasures were proposed to improve the urban water eco-environment quality in the Yangtze River Basin in the 14th Five-Year Plan period.