引用本文: | 孟江槐,康满春,纪道斌,刘佳,肖尚斌,胡杰茗,韩燕星.三峡水库典型支流库湾沉积物CH4产生和氧化规律.湖泊科学,2023,35(5):1670-1681. DOI:10.18307/2023.0527 |
| Meng Jianghuai,Kang Manchun,Ji Daobin,Liu Jia,Xiao Shangbin,Hu Jieming,Han Yanxing.CH4 production and oxidation of sediments in the typical tributary of Three Gorges Reservoir. J. Lake Sci.2023,35(5):1670-1681. DOI:10.18307/2023.0527 |
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三峡水库典型支流库湾沉积物CH4产生和氧化规律 |
孟江槐1, 康满春1,2,3, 纪道斌1,2,3, 刘佳1,2,3, 肖尚斌1,2,3, 胡杰茗1, 韩燕星1
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1.三峡大学水利与环境学院, 宜昌 443002;2.三峡库区生态环境教育部工程研究中心, 宜昌 443002;3.三峡水库生态系统湖北省野外科学观测研究站, 宜昌 443002
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摘要: |
以三峡水库香溪河库湾为研究对象,采用原位加密采样(2021年5月)和室内培养方法,结合沉积物特性与水环境因子分析,探讨了香溪河库湾沉积物甲烷(CH4)释放潜力、沉积物-水界面CH4产生和氧化通量空间分布规律及其影响因素。结果表明: 三峡水库泄水期间,香溪河库湾沉积物CH4释放潜力的变化范围是6.35~2029.37 mg/(kg·d), 沉积物-水界面CH4产生通量和氧化通量的变化范围分别为0.04~0.73、0.03~0.62 mmol/(m2·d); 空间上,沉积物CH4释放潜力、沉积物-水界面CH4产生及氧化通量在香溪河库湾和各典型横切面(XX02、XX05和XX06)间表现出空间差异性,主要受水深、TOC和温度的影响。垂向上, CH4产生速率随沉积物深度的增加而减小,表层20 cm沉积物CH4释放潜力占整柱沉积物的70%,可以用于估算库湾沉积物CH4释放潜力。此外,沉积物-水界面CH4产生通量与沉积物总有机碳呈极显著线性正相关关系,与水深呈显著的负相关关系。CH4产生、氧化通量均与温度呈极显著正相关关系,温度升高导致CH4氧化率线性下降, 从而增加沉积物CH4排放。泄水期香溪河库湾沉积物CH4氧化率高达96.62%, 表明进入水体的CH4只是沉积物产生CH4的很小一部分。 |
关键词: 三峡水库 香溪河 沉积物 CH4产生 CH4氧化 |
DOI:10.18307/2023.0527 |
分类号: |
基金项目:国家自然科学基金项目(51979148,51809149)和湖北省自然科学基金创新群体项目(2019CFA032)联合资助。 |
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CH4 production and oxidation of sediments in the typical tributary of Three Gorges Reservoir |
Meng Jianghuai1, Kang Manchun1,2,3, Ji Daobin1,2,3, Liu Jia1,2,3, Xiao Shangbin1,2,3, Hu Jieming1, Han Yanxing1
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1.College of Water Conservancy and Environment, China Three Gorges University, Yichang 443002, P.R. China;2.Engineering Research Center of Eco-Environment in Three Gorges Reservoir Area, Ministry of Education, Yichang 443002, P.R. China;3.Hubei Field Observation and Scientific Research Stations for Water Ecosystem in Three Gorges Reservoir, Yichang 443002, P.R. China
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Abstract: |
In order to study the extent of CH4 release at the sediment-water interface (SWI) of the tributary bay of the Three Gorges Reservoir (TGR), CH4 production and oxidation at the SWI and its regulators in the Xiangxi Bay were investigated by combining in situ sampling and indoor incubation with sediment characteristics and environmental factors. The results showed that: (1) During the discharge period of the TGR, the potential sediment CH4 production rate (MPs) (6.35-2029.37 mg/(kg·d)), CH4 production fluxes (MP, 0.04-0.73 mmol/(m2·d)) and oxidation fluxes (MO, 0.03-0.62 mmol/(m2·d)) at the SWI showed spatial variations among several transections and increased from downstream (XX00) to upstream (XX07). (2) Vertically, the CH4 production rate decreased with increasing sediment depth, and MPs from the top 20 cm of sediment can be used to estimate sediment MPs in the bay, which accounted for 70% (55%-82%) of the total CH4 production from the intact sediment core (between 20 cm and 36 cm in length). (3) MP at the SWI was positively and linearly related to sediment total organic carbon, but negatively related to water depth. MP and MO showed a very significant positive correlation with increasing temperature, resulting in higher CH4 emission corresponding to a linear decrease in methane oxidation rate (MR). Accordingly, the sediment MR in Xiangxi Bay reached 96.62% during the discharge period of the TGR, indicating low CH4 emission from sediments. |
Key words: Three Gorges Reservoir Xiangxi Bay sediment CH4 production CH4 oxidation |
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