Watershed and catchment area-based water quality management are important methods for comprehensive management of rivers and lakes. The impacts of land use/land cover (LULC) on river water quality vary with spatial scales, such as watersheds, catchments, and riparian zones. Achieving an effective spatial scale relationship between LULC and water quality, determining priority management areas, and reaching sustainable development of large estuarine deltas remain problematic. In this study, buffering analysis on the water quality data of the Yangtze River Estuary from 2009 to 2018 was conducted based on LULC, and the priority management areas of the basin were identified. Also, we infer that future river restoration or management efforts should focus on priority management area construction of a 1500 m riparian zone and a 150 km reach zone. Conclusively, establishing a priority management area within the effective buffer zone is key to watershed water quality management.

流域、流域水质管理是江河湖泊综合治理的重要手段。土地利用/土地覆盖 (LULC) 对河流水质的影响因空间尺度而异，例如流域、集水区和河岸带。在土地利用和土地利用与水质之间实现有效的空间尺度关系、确定优先管理区域以及实现大型河口三角洲的可持续发展仍然是一个难题。本研究基于LULC对长江口2009—2018年水质数据进行缓冲分析，识别流域优先管理区域。同时，我们推断，未来河流的恢复或管理工作应重点关注1500米河岸带和150公里河段带的优先管理区建设。