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| 山地深水湖库水生态健康诊断与风险防控研究
——以中国西南地区藤子沟水库为例 |
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李伟1, 李锗镡2, 赵丽3, 杨巍4, 肖邦2, 汤杨阳2, 赵亮5
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1.（通讯作者）：重庆大学环境与生态学院，三峡库区生态环境教育部重点实验室，副教授，博士生导师，liweieco@cqu.edu.cn;2.重庆大学环境与生态学院，硕士研究生;3.重庆市生态环境科学研究院，正高级工程师;4.重庆大学环境与生态学院，博士研究生;5.重庆大学环境与生态学院，副教授
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| 摘要: |
| 山地深水湖库是我国西南地区兼具
防洪、发电、供水和观光等多重功能的重要
水体，但近年来频发蓝藻水华，威胁水生态
健康与人居环境。本研究以重庆石柱藤子沟
水库为例，于2022—2023 年开展水质、藻
类、鱼类及底栖动物监测，系统诊断其生态
健康状况并识别风险驱动机制。结果表明：
水库水质总体为Ⅲ类，但总磷、溶解氧、酸
碱度超标率分别达47.78%、26.54% 和
24.69%；水体呈中营养—轻度富营养状态，
夏季蓝藻密度峰值达1.79×107 cells/L，形成
轻度水华，主要受高温、营养盐（以农业面
源为主）及水体温度分层共同驱动。建议构
建“监测预警—抑藻控源—生态修复”一体
化防控体系，推广兼具净化与景观功能的生
态工程，从而有效保障山地湖库水生态健
康，持续提升人居环境质量。 |
| 关键词: 水生态健康 生态系统服务 山地
湖库 富营养化 流域管理 |
| DOI：10.13791/j.cnki.hsfwest.20250913001 |
| 分类号: |
| 基金项目:重庆市生态环境局科研项目（2022-118）；国家自然科学基金项目（31700401、U20A20326） |
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| Water ecological health assessment and risk management of mountainous deep-waterreservoirs: A case study of Tengzigou Reservoir in southwest China |
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LI Wei,LI Zhexin,ZHAO Li,YANG Wei,XIAO Bang,TANG Yangyang,ZHAO Liang
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| Abstract: |
| Mountainous deep-water reservoirs, formed by damming river channels and impounding
water in valley depressions, represent a distinctive landscape type in southwest China. These
reservoirs provide essential ecosystem services—including flood control, hydropower generation,
water supply, and recreational opportunities—and are increasingly recognized as critical nodes for
regional ecological security and human well-being. A representative case is the Tengzigou Reservoir
in Chongqing’s Shizhu County, designated as a National Wetland Park in 2019 due to its ecological
and scenic value. Since 2014, this reservoir has experienced recurrent seasonal cyanobacterial blooms,
raising concerns about aquatic ecological health and the suitability of the local living environment.To
address these challenges, this study conducted comprehensive in situ monitoring from April 2022 to
March 2023 across eight sampling sites within the reservoir and its two main tributaries (Shazi River
and Yuelai River). The investigation integrated physical, chemical, and biological indicators—
including water quality parameters (e. g., total phosphorus, dissolved oxygen, pH, total nitrogen),
phytoplankton community structure, fish assemblages, and benthic macroinvertebrates—to
holistically assess the reservoir’s ecological status.Results indicated that the overall water quality of
Tengzigou Reservoir was classified as Grade III according to China’s Surface Water Environmental
Quality Standards (GB 3838–2002). However, significant spatiotemporal heterogeneity was observed.
Total phosphorus exhibited the highest exceedance rate at 47.78%, with concentrations ranging from
0.003 to 0.35 mg/L (mean: 0.05 mg/L). Dissolved oxygen fell below the Class III threshold in 26.54%
of samples, with some deep-layer measurements dropping below 1 mg/L, indicating localized
hypoxia. pH exceeded the upper limit of 9 in 24.69% of samples, with a mean value of 8.17. Total
nitrogen exceeded the Class III standard in 16.96% of samples (range: 0.11–2.05 mg/L; mean: 0.65
mg/L), while ammonia nitrogen and chemical oxygen demand rarely surpassed thresholds. The
reservoir is in a mesotrophic to lightly eutrophic state. Chlorophyll-a concentrations ranged from 1.4
to 17.5 μg/L (mean: 6.6 μg/L), with 9.36% of values exceeding 10 μg/L—indicative of elevated algal
biomass. A total of 13 algal species were identified, primarily comprising green algae, cyanobacteria,
diatoms, cryptophytes, and dinoflagellates. Cyanobacteria dominated during summer months (June to
October), peaking in July when they accounted for 70.38% of the phytoplankton community. Bluegreen
algal density reached a maximum of 1.79×107 cells/L in July 2022 at the Yuelai River inflow
zone (S5 to S7), constituting a mild surface bloom. Densities were significantly lower in spring andwinter, with cyanobacteria undetectable from December to March.Biological surveys recorded 24 fish species, including 20 Cypriniformes, 1 Perciformes, and
3 Siluriformes. Dominant species included crucian carp, common carp, silver carp, and topmouth gudgeon. Six species were endemic to China, and one
invasive species (mirror carp) was detected. Most fish (21 of 24) were adapted to lentic or slow-flowing habitats, reflecting the reservoir’s altered hydrology.
Trophic composition included 11 omnivorous, 10 carnivorous, and 3 herbivorous species, suggesting a moderately complex food web without strong
dominance by filter-feeders. A total of 23 benthic taxa were identified, predominantly aquatic insects (22 taxa), especially Diptera (Chironomidae) and
Ephemeroptera, along with one annelid species. Chironomid larvae dominated in the reservoir core (S4) from August to October, while site-specific shifts
occurred in tributaries—such as Trichoptera in Yuelai River in August, and different Ephemeroptera genera in September and October. The prevalence of
pollution-tolerant Chironomidae indicates potential eutrophication stress.Vertical profiling revealed strong thermal stratification in the deep reservoir basin (S3)
during summer. A distinct thermocline formed between 2-5 m depth in July, with a temperature gradient exceeding 10 ℃ between epilimnion and hypolimnion.
In contrast, inflow rivers (e. g., S1) remained fully mixed throughout the monitoring period. Nutrient analysis showed that total phosphorus concentrations
averaged 0.04 mg/L in July—exceeding the 0.02 mg/L bloom warning threshold—but declined sharply to 0.006 mg/L by September during prolonged dry
conditions with minimal rainfall. This rapid decrease, coinciding with the cessation of surface runoff, underscores the dominant contribution of agricultural nonpoint
sources to phosphorus loading, as further confirmed by source apportionment indicating that 85% of total phosphorus originated from agricultural
activities. These results indicate that the Tengzigou Reservoir watershed maintains a generally favorable aquatic ecological condition, yet faces latent risks.
While biological indicators suggest the absence of severe eutrophication, recurrent seasonal cyanobacterial blooms remain a concern. These blooms are closely
linked to high water temperatures, elevated phosphorus levels—primarily from agricultural non-point sources—and summer thermal stratification. To address
these challenges, it recommends establishing a bloom monitoring and early-warning system tailored to mountainous deep-water reservoirs. Ecological reservoir
operations should be optimized to weaken thermal stratification, while algal suppression measures can be deployed in high-risk zones. Crucially, watershedscale
control of agricultural runoff—through buffer strips, improved fertilizer management, and best practices—is essential to reduce phosphorus loading.
Integrating ecological functions with aesthetic landscape design along shorelines can further enhance both water quality and livability. Sustained
implementation of this integrated approach will support long-term ecological resilience and regional sustainability. |
| Key words: water ecological health ecosystem services mountainous reservoir eutrophication watershed management |
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