清江流域典型发电水库甲烷源汇时空变化规律研究  

Spatial-temporal variation of methane source and sink from the representative reservoir over Qingjiang river basin

作　　者：赵登忠[1,2] 程学军[1,2] 汪朝辉[1,2] 胡承芳[1,2] 肖潇[1,2] 

机构地区：[1]长江水利委员会长江科学院,武汉430010 [2]长江科学院流域水资源与生态环境科学湖北省重点实验室,武汉430010

出　　处：《水力发电学报》2014年第5期128-137,共10页Journal of Hydroelectric Engineering

基　　金：科技部国际合作项目(2012DFR70760);国家软科学研究计划项目(2012GXS2B008);中国清洁发展机制基金资助(2013015);国家自然科学青年基金项目(51009011)

摘　　要：发电水库甲烷源汇时空变化是评估水电清洁能源属性的重要方面,也是分析水电工程对流域生态系统碳循环的重要依据。研究方案采用静态箱与便携式痕量气体分析仪相结合的方法,选择清江流域水布垭水库为典型研究区,在2010年9月到2012年11月期间开展了水库不同典型区域水气界面甲烷扩散通量及其影响因素的原位观测实验。数据分析表明,水布垭水库甲烷平均扩散通量为0.684±0.763mg/(m2·d),其中2010年9月份排放量最大,达到2.152±1.171 mg/(m2·d),最小值则出现在2011年3月份,仅为0.114±0.087 mg/(m2·d)。水库上游和支流典型观测点甲烷处于较高的排放水平,分别达到0.902±0.702 mg/(m2·d)和0.845±0.703 mg/(m2·d),反而在坝前观测点甲烷排放通量是最低的,其通量仅为0.419±0.379 mg/(m2·d)。影响因素分析表明,甲烷通量与表层水体溶解氧、叶绿素、水温度和电导率呈现显著的正相关关系,而与表层水体总碳和pH值呈现较为明显的反相关关系。Spatial-temporal variation of methane source and sink from hydroelectric reservoir is an important factor in evaluation of the clean energy credentials of hydropower and the effects of hydropower project construction on ecosystem carbon cycle over the basin. In this study, we selected the Shuibuya reservoir as a representative over the Qingjiang river basin for measurement of methane diffuse fluxes at the air-water interface in the period from Sep. 2010 to Nov. 2012, using a combination method of floating box and portable trace gas. Data analysis indicates that mean methane flux was 0.684±0.763 mg/（m^2·d）, with a peak of 2.152±1.171 mg/（m^2·d） in Sep. 2010 and a minimum of 0.114±0.087 mg/（m^2·d） in Mar. 2011. Among all the spatial locations sampled, higher emission levels of 0.902±0.702 and 0.845±0.703 mg/（m^2·d） were measured at the far upstream from the dam and the outlets of tributaries respectively, and lover level of 0.419±0.379 mg/（m^2·d） behind the dam. The fluxes over the reservoir is positively related with dissolved oxygen, chlorophyll, water temperature, and conductivity from surface water-body, but negatively related with pH value and total carbon in the surface layer of impoundment.

关 键 词：环境水利 甲烷通量 表层水体 清江流域 水布垭水库 时空变化 

分 类 号：P342[天文地球—水文科学]