| 摘要: |
| 摘 要：池塘和小型水库作为中国数量最多、分布最广的水体，是碳收支核算的重要组成部分。随着塘库水体富营养化加剧，水体的碳排放过程发生变化，增加了塘库碳排放通量计算的不确定性。本研究以竹溪河流域两个池塘、三个水库为研究对象，开展为期九个月的水－气界面CO2、CH4通量监测，并在此基础上进一步探讨小型水体富营养化对CO2、CH4排放的影响。结果表明中度富营养化塘库的CO2、CH4平均排放通量高于轻度富营养化、中营养的塘库，同时轻度富营养化塘库的CO2、CH4平均排放通量高于中营养塘库；对应的水－气界面中营养塘库的CO2平均排放通量为17.32 mmol·m-2·d-1，CH4平均排放通量为0.42 mmol·m-2·d-1；轻度富营养化塘库的CO2平均排放通量为17.89 mmol·m-2·d-1，CH4平均排放通量为0.48 mmol·m-2·d-1；中度富营养化塘库的CO2平均排放通量为19.37 mmol·m-2·d-1，CH4平均排放通量为0.78 mmol·m-2·d-1；整体表现为CO2、CH4的源。CO2、CH4排放通量与各个季节及温度、溶解氧和pH等影响因素综合变化有关。随着小型水体塘库富营养化水平的提高，CO2、CH4排放通量呈非线性增加的趋势，中度富营养化水体的CH4排放通量约是中营养水体的两倍，这表明降低水体富营养化水平可有效减少水体CH4等温室气体排放。因此，为准确估算和预测小型水体CO2和CH4等温室气体排放量，应将富营养化水平作为潜在的影响因素。 |
| 关键词: 富营养化 塘库 CO2通量 CH4通量 影响因素 |
| DOI： |
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| 基金项目:国家自然科学基金项目(42071242)、三峡水库重庆库区长江干流及重要支流健康评价（CQS23C01036)） |
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| CO2 and CH4 Emission Characteristics of Eutrophic Ponds and Reservoirs in Hilly and Mountainous Areas |
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maqi1, Lv Mingquan2, wang xingping, wang yao, Xingqiao3
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1.Chongqing Jiaotong University;2.Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences;3.Chongqing River Affairs Center
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| Abstract: |
| Abstract: The ponds and small reservoirs, being the most numerous and widely distributed water bodies in China, are an important component in the accounting of carbon balance. With the increasing eutrophication of these water bodies, the carbon emission processes have changed, leading to greater uncertainty in calculating the carbon emission fluxes of ponds and reservoirs Zhuxi River Basin, conducting a nine-month monitoring of CO2 and CH4 fluxes at the water-air interface. Based on the monitoring results, the study further explores the impact of eutrophication in small water bodies on CO2 and CH4 emissions. The results show that the average CO2 and CH4 emission fluxes from moderately eutrophic ponds are higher than those from lightly eutrophic and mesotrophic ponds. At the same time, the average CO2 and CH4 emission fluxes from lightly eutrophic ponds are higher than those from mesotrophic ponds; the average CO2 emission flux at the water-air interface in mesotrophic ponds and reservoirs is 17.32 mmol·m-2·d-1, and the average CH4 emission flux is 0.42 mmol·m-2·d-1. In mildly eutrophic ponds and reservoirs, the average CO2 emission flux is 17.89 mmol·m-2·d-1, and the average CH4 emission flux is 0.48 mmol·m-2·d-1. In moderately eutrophic ponds and reservoirs, the average CO2 emission flux is 19.37 mmol·m-2·d-1, and the average CH4 emission flux is 0.78 mmol·m-2·d-1. Overall, the study found that these water bodies act as sources of CO2 and CH4. The fluxes of CO2 and CH4 emissions are influenced by various factors, including seasonal changes, temperature, dissolved oxygen, and pH. With the increase in eutrophication of small water bodies, the emission fluxes of CO2 and CH4 show a nonlinear increasing trend. The CH4 emission flux in moderately eutrophic water bodies is approximately twice that of mesotrophic waters, indicating that reducing the eutrophication level can effectively decrease greenhouse gas emissions such as CH4 from water bodies. Therefore, to accurately estimate and predict greenhouse gas emissions such as CO2 and CH4 from small water bodies, eutrophication levels should be considered as a potential influencing factor. |
| Key words: Eutrophication Ponds and reservoirs CO? flux CH? flux Influencing factors |
