千峡湖水库温室气体排放时空特征及其环境驱动因素  

Spatio-temporal emission characteristics and environmental factors of greenhouse gases in Qianxiahu Reservoir

作　　者：张政 刘梅[1] 周聃 郭爱环[1] 练青平[1] 罗凯[2] 许巧情[2] 陈光美 原居林[1] ZHANG Zheng;LIU Mei;ZHOU Dan;GUO Aihuan;LIAN Qingping;LUO Kai;XU Qiaoqing;CHEN Guangmei;YUAN Julin(Zhejiang Provincial Key Laboratory of Freshwater Aquatic Genetics and Breeding,Key Laboratory of Healthy Freshwater Fishery Aquaculture of Ministry of Agriculture and Rural Affairs,Zhejiang Freshwater Fisheries Research Institute,Huzhou 313001;College of Animal Science and Technology,Yangtze University,Jingzhou 434020;Zhejiang Fenghe Fishery Co.,Ltd.,Lishui 323000)

机构地区：[1]浙江省淡水水产研究所,农业农村部淡水渔业健康养殖重点实验室,浙江省淡水水产遗传育种重点实验室,湖州313001 [2]长江大学动物科学技术学院,荆州434020 [3]浙江丰和渔业有限责任公司,丽水323000

出　　处：《环境科学学报》2024年第7期388-401,共14页Acta Scientiae Circumstantiae

基　　金：浙江省重点研发“领雁”项目(No.2022C02071);湖州市公益应用研究项目(No.2022GZ24);浙江省自然科学金(No.LTGS23C030005);农业农村部淡水渔业健康养殖重点实验室开放项目(No.ZJK202312)。

摘　　要：以峡谷型水库千峡湖水库为研究对象,采用顶空平衡法对千峡湖水库表层水样中溶存的CO_(2)、CH_(4)和N_(2)O浓度进行每月一次周年测定,同时使用静态浮箱法对水-气界面温室气体交换通量进行监测.结果显示,千峡湖水库表层水体CH_(4)、N_(2)O和CO_(2)浓度最高都出现在春季,分别为(0.25±0.099)、(0.0078±0.0032)、(7.62±2.73)μmol·L^(-1);CH_(4)、N_(2)O最低浓度出现在冬季,分别为(0.11±0.074)、(0.00039±0.0018)μmol·L^(-1),CO_(2)的最低浓度出现在夏季((3.05±1.51)μmol·L^(-1));水库表层扩散通量CH_(4)、N_(2)O的最高扩散通量分别出现在夏冬两季,分别为(6.92±3.61)、(0.49±0.38)μmol·m^(-2)·h^(-1);水库表层CO_(2)扩散通量全年平均值为负值,最高吸收通量发生在夏季((-1973.53±1226.43)μmol·m^(-2)·h^(-1)).从全球增温潜势上看,千峡湖水库是大气的“碳汇”,水-气界面温室气体通量存在较为明显的时空变化特征.时间上,夏季水体中CH_(4)浓度与通量均显著高于冬季(p<0.05),N_(2)O的排放通量总体上秋冬季高于春夏季,同时CO_(2)浓度在春季显著高于夏秋两季;空间上,水-气界面温室气体扩散通量在各个季节也存在不同的空间变异性.统计分析表明,温度是影响千峡湖水库水-气界面3种温室气体排放的共同驱动因素(p<0.05),CO_(2)的扩散通量还受DO、大气压强等环境因子影响(p<0.05);CH_(4)的排放通量受DO、压强和风速影响,且与DO呈显著负相关(p<0.01),与压强、风速呈正相关(p<0.05);N_(2)O的扩散通量受水体富营养化程度调控,与水体中无机氮的浓度呈显著正相关(p<0.05).The Qianxiahu Reservoir,characterized as a canyon-type reservoir,was taken as the research object in this study.The CO_(2),CH_(4) and N_(2O) concentrations in the surface water samples were measured once a month for a year using the headspace equilibrium method.Simultaneously,greenhouse gas emission at the water-air interface was monitored by the static floating method.Results revealed that the highest concentrations of CH_(4),N_(2O) and CO_(2) in the surface water were (0.25±0.099)μmol·L^(-1),(0.0078±0.0032)μmol·L^(-1),and (7.62±2.73)μmol·L^(-1),respectively,occurring in spring.The lowest concentrations of CH_(4) and N_(2O) were (0.11±0.074)μmol·L^(-1) and (0.00039±0.0018)μmol·L^(-1) in winter,while the lowest concentrations of CO_(2) was (3.05±1.51)μmol·L^(-1) in summer.The highest surface emission fluxes of CH_(4) and N_(2O) were (6.92±3.61)μmol·m^(-2)·h^(-1) and(0.49±0.38)μmol·m^(-2)·h^(-1 )in summer and winter,respectively.The annual mean value of CO_(2) emission flux from the reservoir surface water was negative,with the maximum flux recorded as (-1973.53±1226.43)μmol·m^(-2)·h^(-1 )in summer.The global warming potential (GWP) indicated that Qianxiahu Reservoir to be a"carbon sink",with observable spatio-temporal variations in greenhouse gas fluxes.Temporal analysis revealed that CH_(4) concentration and flux in summer significantly exceeded those in winter (p<0.05),N_(2O) emission flux in autumn and winter surpassed that in spring and summer,and CO_(2 )concentration in spring was notably higher than in summer and autumn.Spatially,the greenhouse gas flux at the water-gas interface exhibited distinct variability across different seasons.Statistical analysis identified temperature as the common driving factor influencing the emissions of the three greenhouse gases(p<0.05).Meanwhile,CO_(2) emission is also affected by environmental factors such as water DO and atmospheric pressure (p<0.05).However CH_(4) emission exhibited a significant negative correlation with water DO (p<0.01),b

关 键 词：温室气体 溶存浓度 扩散通量 碳汇 驱动因素 千峡湖水库 

分 类 号：X523[环境科学与工程—环境工程] X51