富营养化咸水湖泊岱海温室气体排放特征及驱动因素分析  

Greenhouse Gas Emissions Characteristics and Driving Factors Analysis in the Eutrophic Saline Lake Daihai Lake

作　　者：卢宗福 史小红[1,2] 李国华 LU Zong-fu;SHI Xiao-hong;LI Guo-hua(College of Water Conservancy and Civil Engineering,Inner Mongolia Agricultural University,Hohhot 010018,China;Key Laboratory of Water Resources Protection and Utilization,Inner Mongolia Agricultural University,Hohhot 010018,China)

机构地区：[1]内蒙古农业大学水利与土木建筑工程学院,呼和浩特010018 [2]内蒙古自治区水资源保护与利用重点实验室,呼和浩特010018

出　　处：《环境科学》2024年第10期6157-6170,共14页Environmental Science

基　　金：国家自然科学基金地区项目(52260028,52060022,52369014);内蒙古重点研发和成果转化计划项目(2021GG0089,2023YFDZ0022)。

摘　　要：为探究北方富营养化咸水湖泊温室气体排放特征及驱动因素,以内蒙古岱海为例,于2023年4月、7月和10月按水文分布特征选取10个监测点,采用顶空平衡气相色谱法和模型法测定岱海近岸带、开阔湖区和湖心区表层水体中二氧化碳(CO_(2))、甲烷(CH_(4))和氧化亚氮(N_(2)O)的溶存浓度和水-气界面交换通量.研究期间,岱海温室气体浓度和通量季节变化显著;表层水体CO_(2)、CH_(4)和N_(2)O浓度平均值为(26.52±17.58)μmol·L^(-1)、(282.30±172.30)nmol·L^(-1)和(9.09±1.64)nmol·L^(-1),平均通量为(5.29±11.98)mmol·(m^(2)·d)^(-1)、(178.24±63.34)μmol·(m^(2)·d)^(-1)和(-0.74±1.28)μmol·(m^(2)·d)^(-1),累计排放量为50770.77、543.52和-4.21 kg·km^(-2),全球增温潜势[以CO_(2)当量(CO_(2)-eq)计]为50770.77、15218.49和-1254.48 kg·km^(-2).结果表明,岱海是大气CO_(2)和CH_(4)的源,是N_(2)O的汇.对温室气体与环境因子进行相关分析和逐步回归分析,发现影响岱海CO_(2)浓度和通量的环境因子为酸碱度(pH)和总溶解性固体(TDS);影响CH4浓度和通量的因子为水温(WT)、水深(WD)、风速(WS)、氧化还原电位(ORP)和总氮(TN);影响N_(2)O浓度和通量的因子为WT、WS和TN.此外,岱海自身的营养水平和盐度特性也是影响温室气体产生和排放的关键因素.To investigate the greenhouse gas emission characteristics and driving factors of eutrophic saline lakes in northern China,considering Daihai Lake in Inner Mongolia as an example,10 monitoring sites were selected based on hydrological distribution characteristics in April,July,and October 2023.Using headspace gas chromatography and modeling methods,dissolved concentrations and exchange fluxes of carbon dioxide(CO_(2)),methane(CH_(4)),and nitrous oxide(N_(2)O)were determined in the nearshore zone,open lake area,and lake center surface water.During the study period,Daihai Lake exhibited significant seasonal variations in greenhouse gas concentration and flux.The average concentrations of CO_(2),CH_(4),and N_(2)O in surface water were(26.52±17.58)μmol·L^(-1),(282.30±172.30)nmol·L^(-1),and(9.09±1.64)nmol·L^(-1),respectively.The average fluxes were(5.29±11.98)mmol·(m^(2)·d)^(-1),(178.24±63.34)μmol·(m^(2)·d)^(-1),and(-0.74±1.28)μmol·(m^(2)·d)^(-1),with cumulative emissions of 50770.77,543.52,-4.21 kg·km^(-2) and a global warming potential(expressed in CO_(2)-equivalent)of 50770.77,15218.49,-1254.48 kg·km^(-2).Daihai Lake acted as a source of atmospheric CO_(2)and CH_(4) but a sink for N_(2)O during the study period.Correlation and stepwise regression analyses revealed that pH and total dissolved solids(TDS)influenced CO_(2)concentration and flux,while the factors affecting CH_(4) were water temperature(WT),water depth(WD),wind speed(WS),oxidation-reduction potential(ORP),and total nitrogen(TN).For N_(2)O,the influencing factors were WT,WS,and TN.Additionally,Daihai Lake's eutrophication and salinity characteristics influenced the generation and emission of greenhouse gases.This study provides insights into the greenhouse gas dynamics and environmental factors in eutrophic saline lakes like Daihai Lake.

关 键 词：岱海 营养水平 咸水湖 温室气体 碳氮排放 全球增温潜势(GWP) 

分 类 号：X16[环境科学与工程—环境科学]