摘要
为探究亚洲最大城中湖武汉市汤逊湖水体溶存CO_(2)浓度(pCO_(2))及水-气界面CO_(2)通量(FCO_(2))日变化规律,于冬季(1周)和夏季(3个昼间)对汤逊湖的两个样点(TXH1和TXH2)进行表层水样分析,并用水质参数仪和风速仪现场测定环境气象因子(pH、DO、DO%、EC、水温、气温、风速),在实验室测定碱度。用CO_(2)SYS模型计算(水温、pH和碱度)水体pCO_(2),薄边层模型计算湖泊水-气界面FCO_(2),研究结果表明pCO_(2)和FCO_(2)在日尺度及季节尺度上有着显著性差异,且两个取样点间有显著性差异。汤逊湖存在CO_(2)"源/汇"功能转换,整体上呈现"源"的特征。TXH1表层水pCO_(2)均值为585.5±758.2μatm,FCO_(2)均值为3.52±20.58 mmol/(m^(2)·d);TXH2表层水pCO_(2)均值为799.3±579.4μatm,FCO_(2)均值为6.53±14.81 mmol/(m^(2)·d)。冬季TXH2表层水pCO_(2)均值(1032.1±183.5μatm)高于TXH1(均值为348.2±119.8μatm);夏季TXH2表层水pCO_(2)(均值为391.9±783.1μatm)低于TXH1(均值为1000.7±1143.8μatm);冬季TXH2的FCO_(2)平均值(13.94±3.91 mmol/(m^(2)·d))高于TXH1的平均值(-1.36±2.80 mmol/(m^(2)·d),夏季TXH2的FCO_(2)平均值(-6.43±17.77 mmol/(m^(2)·d))低于TXH1的平均值(12.06±32.49 mmol/(m^(2)·d))。pCO_(2)和FCO_(2)受环境因子EC、DO、水温、气温的影响,并通过逐步回归分析得到DO和水温是影响FCO_(2)的主要环境因子。通过pCO_(2)和FCO_(2)各时间点均值和总均值比较,发现11:30~12:00时取样能较好地代表冬季8:00~15:30时之间的水-气界面碳释放,8:00~9:00时取样能较好地代表夏季7:00~18:30时之间的水-气界面碳释放。
This study explores dissolved CO_(2) concentration(pCO_(2))and CO_(2) flux(FCO_(2))at water-air interface of the Tangxun Lake in Wuhan,the largest urban lake in Asia.The Tanxun Lake is located in the subtropical monsoon climate zone,30°25′12″N,114°24′42″E,with four distinct seasons and large difference in temperature between summer and winter seasons.The average temperature is 28.8~31.4℃in July,and the lowest temperature is 2.6~4.6℃in January.The average annual precipitation in the lake area is 1300 mm/a.Precipitation is concentrated in April to July,accounting for about 60%of the annual precipitation.The surface runoff depth is 490 mm.The day-time variations of dissolved CO_(2) concentration(pCO_(2))and CO_(2) flux(FCO_(2))at the water-air interface in relation to eutrophication gradients and seasons were detaily examined in the Tanxun Lake.The surface water samples of two sample sites(TXH1 and TXH2)in the Tangxun Lake were analyzed in winter(1 week)and summer(3 days).The environmental meteorological factors(pH,DO,DO%,EC,water temperature,air temperature,wind speed)were measured on site with water quality parameter instrument and anemometer,and the alkalinity was measured in the laboratory.The CO_(2) SYS model was used to calculate the water pCO_(2) using water temperature,pH and alkalinity,and the thin boundary model was consequently used to calculate the lake water-air interface FCO_(2).The results showed that there were significant differences between pCO_(2) and FCO_(2) on the daily scale and seasonal scale,and there were significant differences between the two sampling points.The Tangxun Lake shows a shift in CO_(2)"source/sink"function,showing the characteristics of"source"on the whole.The mean values of pCO_(2) and FCO_(2) in the TXH1 surface water were 585.5±758.2μatm and 3.52±20.58 mmol/(m^(2)·d)respectively.The mean pCO_(2) and FCO_(2) of the TXH2 surface water were 799.3±579.4μatm and 6.53±14.81 mmol/(m^(2)·d)respectively.In winter,the mean value of surface water pCO_(2)(1032.1±
作者
田小康
吴忠立
林斯静
殷美绮
杨富伟
谭东杨
李思悦
TIAN Xiaokang;WU Zhongli;LIN Sijing;YIN Meiqi;YANG Fuwei;TAN Dongyang;LI Siyue(School of Environmental Ecology and Biological Engineering,Wuhan Institute of Technology,Wuhan 430205,Hubei)
出处
《第四纪研究》
CAS
CSCD
北大核心
2023年第2期625-636,共12页
Quaternary Sciences
基金
武汉工程大学高层次人才启动项目(批准号:21QD02)
国家自然科学基金项目(批准号:31670473)共同资助。
关键词
水-气界面
日变化
环境因子
薄边层模型法
water-air interface
daily variation
environmental factors
thin boundary layer model method
