汤逊湖是我国最大的城中湖,在防洪排涝和生态景观方面发挥着重要作用。随着城市化进程的加速以及人类活动的日益频繁,汤逊湖水质一度恶化、水生态遭到破坏,虽然近年来有所好转,但是水资源、水环境、水生态问题仍然相互交织。急需构建科学全面的湖泊健康状况评价体系,从多维度对汤逊湖健康状况进行动态跟踪评价,并提出科学合理的湖泊保护建议。从水资源、水环境和水生态3方面,基于遥感影像、地面监测、统计公报等多源信息,对2017—2024年汤逊湖健康状况进行了动态评估。结果表明,近年来汤逊湖湖泊健康综合评分总体呈现上升趋势,由2017年的69.27上升至2024年的77.17,湖泊健康状况逐年向好。存在的问题包括汤逊湖主要污染物(总磷)浓度仍然较高、湖泊水质与目标值(Ⅲ类)仍有一定差距、干旱年份枯水期生态水位满足程度较低、湖泊生态景观功能受限。提出了加强汤逊湖水环境综合治理、强化汤逊湖生态水位保障、推进生态景观品质提升等方面对策,为汤逊湖治理保护提供了支撑。

[Objective] Tangxun Lake is the largest urban lake in China and plays an essential role in flood control, drainage, and ecological landscape. With rapid urbanization and intensified human activity, the water quality of Tangxun Lake previously deteriorated, and its aquatic ecosystem was degraded. The study aims to develop a scientific and comprehensive evaluation system for the health status of the lake, dynamically track and evaluate the health status of Tangxun Lake from multiple dimensions, and provide evidence-based recommendations for lake protection. [Methods] A health evaluation index system covering multiple dimensions of water resources, water environment, and water ecology was deveoped. The system integrated multiple data sources, including remote sensing images, in situ monitoring data, and statistical bulletins. Indicator weights were assigned based on different lake functions in the “Hubei Province River and Lake Health Assessment Guidelines”, and index values were determined using the Delphi expert method. The health status of Tangxun Lake from 2017 to 2024 was dynamically evaluated. [Results] The water area of Tangxun Lake was well managed during the study period, and the water quality score was generally low but increased annually. In terms of water ecology, the score for wetland-area reduction decreased annually. Collectively, the comprehensive score of the health status of Tangxun Lake increased in recent years, with the health status of the lake improving progressively. The comprehensive score increased from 69.27 in 2017 to 77.17 in 2024. Persistent problems included high concentration of total phosphorus, the main pollutant in Tangxun Lake, and failure to meet the target Class III water-quality standard. In drought years, the ecological water level was low during the dry season, and the ecological landscape function of the lake was limited. [Conclusion] Countermeasures were propsed to support the governance and protection of Tangxun Lake. (1) Strengthen comprehensive management of water environment: further separate rainwater from sewage and clean water from wastewater; rectify mixed and misconnected pipelines to reduce overflow pollution during the rainy season; improve sewage collection, transmission, and treatment system to achieve full coverage of sewage collection pipelines in the catchment area; implement environmental dredging in heavily polluted areas to reduce endogenous pollution in the lake. (2) Strengthen the maintenance of ecological water level in the lake: conduct research on the optimal pre-rain regulated water level of the lake; strengthen monitoring and forecasting of rainfall and hydrological conditions in the catchment area; implement dynamic control of lake water levels during the flood season; conduct ecological water replenishment under extreme drought conditions to ensure attainment of the minimum ecological water level and fully utilize the ecological and landscape functions of the lake.