浅水湖泊冬季温室气体浓度与通量的变化特征及影响因素  

Characterization and Influencing Factors of Dissolved Concentrations and Emission Fluxes of Greenhouse Gases in Winter in a Shallow Lake

作　　者：陈曦 程俊翔[1,3,4] 徐力刚 徐宪根[6] 丁竹红 CHEN Xi;CHENG Junxiang;XU Ligang;XU Xiangen;DING Zhuhong(Key Laboratory of Lake and Watershed Science for Water Security,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 211135,China;School of Environmental Science and Engineering,Nanjing Tech University,Nanjing 211816,China;Poyang Lake Wetland Research Station,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Jiujiang 332899,China;Jiangxi Research Academy of Ecological Civilization,Nanchang 330036,China;University of Chinese Academy of Sciences,Beijing 100049,China;Changzhou Research Academy of Environmental Sciences,Changzhou 213022,China;Jiangxi Provincial Technology Innovation Center for Ecological Water Engineering in Poyang Lake Basin,Nanchang 330029,China)

机构地区：[1]中国科学院南京地理与湖泊研究所,湖泊与流域水安全重点实验室,江苏南京211135 [2]南京工业大学环境科学与工程学院,江苏南京211816 [3]中国科学院南京地理与湖泊研究所鄱阳湖湖泊湿地综合研究站,江西九江332899 [4]江西省生态文明研究院,江西南昌330036 [5]中国科学院大学,北京100049 [6]常州市环境科学研究院,江苏常州213022 [7]江西省鄱阳湖流域生态水利技术创新中心,江西南昌330029

出　　处：《环境科学研究》2024年第11期2478-2489,共12页Research of Environmental Sciences

基　　金：中国博士后科学基金资助项目(No.2024M751237);江苏省碳达峰碳中和科技创新专项资金项目(No.BK20220042);中国科学院南京地理与湖泊研究所科技创新规划项目(No.NIGLAS2022TJ13)。

摘　　要：内陆水体是大气二氧化碳(CO_(2))、甲烷(CH_(4))、氧化亚氮(N_(2)O)的重要自然排放源。为研究浅水湖泊温室气体溶存浓度及排放通量,以太湖流域上游浅水湖泊-长荡湖为例,在冬季(2022年1-2月)利用顶空平衡-气相色谱法对其表层水体温室气体溶存浓度及排放通量进行测定,综合采用方差分析、多元逐步回归分析等方法探究了长荡湖湖区及主要出入湖河口区温室气体溶存浓度与排放通量的空间分布特征及主要影响因素。结果表明:①长荡湖冬季CO_(2)、CH_(4)、N_(2)O平均溶存浓度分别为(40.49±14.18)μmol/L、(0.86±1.92)μmol/L和(18.43±8.44)nmol/L,平均排放通量分别为(49.99±69.49)μmol/(m^(2)·h)、(1.28±2.64)μmol/(m^(2)·h)和(12.01±14.37)nmol/(m^(2)·h)。②在空间分布上,湖区CO_(2)排放通量高于出入湖河口区,湖区CH_(4)、N_(2)O溶存浓度和排放通量均显著低于出入湖河口区。③CO_(2)排放主要受水温、电导率(EC)以及TN、TP和Chla浓度的影响,CH_(4)排放主要受pH、高锰酸盐指数(CODMn)、EC和DO浓度的影响,N_(2)O排放主要受pH以及DO、TN和TP浓度的影响。④长荡湖冬季CO_(2)、CH_(4)和N_(2)O累积排放通量分别为47.51、0.44和0.01 kg/hm^(2),结合水域面积估算得出温室气体排放总量为545.57 t(以CO_(2)当量计)。研究显示,长荡湖冬季温室气体排放呈现较明显的空间异质性,并受到不同区域水环境条件、外源营养输入及人类活动的共同影响。本研究强调了浅水湖泊冬季温室气体排放在内陆水体温室气体收支中的重要性,可为全球和区域湖泊温室气体排放精确估算提供重要支撑。Inland waters are important natural emission sources of atmospheric carbon dioxide(CO_(2)),methane(CH_(4))and nitrous oxide(N_(2)O).In order to reveal the dissolved greenhouse gas(GHG)concentrations and their diffusive fluxes in a shallow lake,we investigated the winter(January to February 2022)greenhouse gas in Changdang Lake,a shallow lake in the upper Taihu Lake Basin.We used the headspace equilibrium-gas chromatography(GC)method to measure the GHG concentrations and emission fluxes in surface water.Analysis of variance(ANOVA)and multiple stepwise regression analysis(MSRA)were used to explore the spatial distribution characteristics and the main factors influencing dissolved GHG concentrations and emission fluxes in the Lake and its main inlet and outlet rivers.The results showed that the mean dissolved CO_(2),CH_(4) and N_(2)O concentrations in Changdang Lake in winter were(40.49±14.18)μmol/L,(0.86±1.92)μmol/L,and(18.43±8.44)nmol/L,respectively.The mean diffusive fluxes were(49.99±69.49)μmol/(m^(2)·h),(1.28±2.64)μmol/(m^(2)·h),and(12.01±14.37)nmol/(m^(2)·h),respectively.From the perspective of spatial distribution,CO_(2) fluxes in Changdang Lake were higher than those in the inlet and outlet rivers,while dissolved CH_(4) and N_(2)O concentrations and their fluxes in the lake were significantly lower than those in the inlet and outlet rivers.Statistical analysis showed that CO_(2) emission was mainly affected by water temperature,electrical conductivity(EC),total nitrogen(TN),total phosphorus(TP)and chlorophyll a(Chla)concentrations.CH_(4) emission was mainly affected by pH,peroxynitrite index(CODMn),EC and DO concentration,and N_(2)O emission was mainly affected by pH,DO,TN and TP concentrations.The cumulative emission fluxes of CO_(2),CH_(4) and N_(2)O from the Changdang Lake in winter were 47.51 kg/hm^(2),20.44 kg/hm and 0.01 kg/hm^(2),respectively,and the total GHG emission was estimated to be 545.57 t(in terms of CO_(2) equivalent)combined with the lake area.Our findings suggest that winter G

关 键 词：浅水湖泊 温室气体 溶存浓度 水-气界面 排放通量 影响因子 

分 类 号：X511[环境科学与工程—环境工程]