漳河水库水体富营养化评价研究

Study on Eutrophication Evaluation of Zhanghe Reservoir

摘要: 湖库富营养化是威胁饮用水安全的主要水环境问题之一。漳河水库是湖北省荆门市中心城区的重要饮用水源地，但目前缺乏对其富营养化状态的连续动态评价及驱动因素的深入探讨。本研究收集2021年1月至2023年12月漳河水库国控断面的水质监测数据，采用综合营养指数法(TLI)分析水体的富营养化程度、时间演变特征及关键驱动因子。结果表明：连续36个月中，漳河水库有35个月呈贫营养状态(TLI(∑) < 30)，仅2023年9月呈中营养状态(TLI(∑) = 30.4)；综合营养状态指数逐月波动，2022年12月最低(20.0)，2023年9月最高(30.4)。分项TLI指数分析显示，高锰酸盐指数(COD_Mn)是影响综合指数波动的关键因子。研究发现2021年8月和2022年4月、9月综合营养状态指数出现三次明显下降，以及2023年9月的峰值，但这些变化与人类活动强度(如大型赛事活动、公共卫生事件应对措施)的关联性，需结合水文、气象等多源数据进一步验证。结论认为，漳河水库水质整体优良，连续三年保持贫营养状态，满足饮用水源要求。未来需构建多因子驱动模型，深入揭示营养状态变化的机制，为水库精准保护提供科学依据。

Abstract: Eutrophication of lakes and reservoirs is a major water environmental issue threatening drinking water safety. Zhanghe Reservoir is an important drinking water source for the central urban area of Jingmen City, Hubei Province. However, there is a lack of continuous dynamic evaluation of its eutrophication status and in-depth analysis of driving factors. Water quality monitoring data from the national control section of Zhanghe Reservoir from January 2021 to December 2023 were collected, and the comprehensive trophic level index (TLI) method was applied to evaluate the eutrophication degree, temporal evolution characteristics, and key driving factors. Results show that among the 36 consecutive months, the reservoir exhibited oligotrophic status (TLI(∑) < 30) in 35 months, and only September 2023 showed mesotrophic status (TLI(∑) = 30.4). TLI values fluctuated monthly, with the lowest of 20.0 in December 2022 and the highest of 30.4 in September 2023. Analysis of sub-indices indicates that permanganate index (COD_Mn) is a key factors influencing the fluctuation of the comprehensive index. Three notable declines in TLI were observed in August 2021 and in April and September 2022, and a peak in September 2023. Although these changes are tentatively linked to variations in human activity intensity (e.g., mass events, public health emergency responses), such attributions remain speculative and require validation with hydrological and meteorological data. It is concluded that the water quality of Zhanghe Reservoir is generally excellent, maintaining oligotrophic status for three consecutive years, meeting the requirements as a drinking water source. Future studies should construct multi-factor driven models to reveal the mechanisms of trophic state changes and provide scientific basis for precise protection of the reservoir.