摘要
本文基于中国境内的湖泊、水库、河流等淡水系统CH4排放研究的相关成果,对203个湖泊(595个样点)、46个水库(221个样点)、112条河流(441个样点),总计1257个样点的CH4通量数据进行统计分析,探讨了中国淡水系统(湖泊、水库、河流)CH4排放的一般特征,总结了当前研究进展,并进一步估算和评估了中国淡水系统CH4排放总量水平.结果表明:1)中国湖泊CH4排放通量平均为(1.17±1.87)mg/(m^2·h),蒙新湖区((3.84±0.57)mg/(m^2·h))和东北湖区((2.62±3.54)mg/(m^2·h))较高,青藏湖区((1.94±4.13)mg/(m^2·h))次之,东部湖区((0.81±0.90)mg/(m^2·h))较低,云贵湖区((0.19±0.26)mg/(m^2·h))最低;湖泊CH4排放通量呈显著的纬度模式,高纬度地区湖泊CH4排放高于低纬度地区;2)水库CH4排放通量((1.25±1.78)mg/(m^2·h))与湖泊相似,水库消落带较高的排放通量((4.34±4.45)mg/(m^2·h))对水库CH4排放具有重要贡献;3)河流CH4排放((0.82±1.14)mg/(m^2·h))略低于湖库,长江水系CH4排放通量((0.98±2.38)mg/(m^2·h))和黄河水系((0.85±0.75)mg/(m^2·h))相近,高于海河水系((0.54±0.93)mg/(m^2·h)),辽河、珠江水系研究较少,数据变异性极大;4)受降水、温度、径流稀释等影响,淡水系统CH4排放呈显著的季节变化,其中湖库排放夏季高于秋季,冬春季较低,而河流则春秋季高于夏冬季;5)基于外推法估算全国湖泊、水库、河流CH4排放总量分别约为0.96,0.29,0.76Tg/a,相当于全国湿地系统排放的75%.由于较大的时空变异性以及监测数据分布的不均匀性,目前估算存在较大的不确定性,但淡水系统CH4排放在全球气候变化中的贡献仍不容小觑.
In this paper,we conducted a comprehensive review of the general characteristics of CH4 emissions from China’s freshwater ecosystems based on a newly complied database.The database included CH4 emission measurements from freshwater systems like lakes,reservoirs and rivers in China.In total,it consisted of 1257 sample points:203 lakes(595sample),46reservoirs(221samples),and 112 rivers(441samples).In addition,total CH4emissions from freshwater ecosystems in China were preliminarily estimated and evaluated.The result showed that:1)the averaged CH4 flux of lakes in China was of(1.17±1.87)mg/(m^2·h).The magnitude of CH4 fluxes showed a great spatial variation among five lake regions in China.Lakes in Meng-xin region had the highest flux at(3.84±0.57)mg/(m^2·h),followed by Northeast region((2.62±3.54)mg/(m^2·h)),Qinghai-Tibet region((1.94±4.13)mg/(m^2·h)),Eastern plain((0.81±0.90)mg/(m^2·h))and Yun-gui region((0.19±0.26)mg/(m^2·h)).Moreover,CH4 flux from lakes showeda significant latitude pattern,i.e.CH4 flux increased with latitude escalating,that was contrary to the global pattern.2)CH4 flux in reservoirs((1.25±1.78)mg/(m^2·h))was similar to that in lakes.Especially,the extremely higher CH4 flux was generally found in reservoir littoral zones((4.34±4.45)mg/(m^2·h)),a big contributor to the reservoir’s total CH4emissions.3)Riverine CH4 flux was(0.82±1.14)mg/(m^2·h),lower than those from lakes and reservoirs.The majority of the researches on riverine CH4 emissions were concentrated in the Yangtze River and Yellow River system,which had averaged CH4 fluxes of(0.98±2.38)and(0.85±0.75)mg/(m^2·h),respectively.Lower CH4 emission was found in Haihe system((0.54±0.93)mg/(m^2·h)),and scattered researches focused on Liaohe and Pearl River systems,which might lead to a high degree of variations in those CH4 emission data points.4)CH4 fluxes in freshwater systems of China also showed a seasonal variation.CH4 fluxes from lakes and reservoirs were higher in summer,while riverine CH4 fluxes were higher in spring and autumn than summer and winter.Such seasonal variations were probably affected by precipitation,temperature,and runoff dilution.5)Based on universal extrapolation,we roughly estimated the total CH4 emissions from all lakes,reservoirs and rivers in China were 0.96,0.29,0.76Tg/a,respectively,with a total of 2.01 Tg/a,equivalent to 75%of the total CH4 emission from China wetland systems.Given the strong spatiotemporal variability and the uneven distribution of monitoring data,our estimation had a large uncertainty.Nonetheless,we concluded that CH4 flux in Chinese freshwater system was a contributor to regional carbon budget and global greenhouse gas emission.
作者
张佩
王晓锋
袁兴中
ZHANG Pei;WANG Xiao-feng;YUAN Xing-zhong(Key Laboratory of New Technology for Construction of Cities in Mountain Area,Ministry of Education,Faculty of Architecture and Urban Planning,Chongqing University,Chongqing 400030,China;Key Lab of Three Gorges Reservoir Region’s Eco-Environment,Ministry of Education,College of Environment and Ecology,Chongqing University,Chongqing 400030,Chinа;Chongqing Key Laboratory of Wetland Science Research of the Upper Yangtze River,Chongqing 401331,China;College of Geography and Tourism,Chongqing Normal University,Chongqing 401331,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2020年第8期3567-3579,共13页
China Environmental Science
基金
国家科技重大专项(2013ZX07104-004-05)
国家自然科学基金资助项目(41807321)
重庆市科委基础研究与前沿探索(cstc2018jcyjAX0672)
中央高校基本科研业务费专项项目(2018CDJCZX06)。
关键词
湖泊
水库
河流
甲烷排放
中国
lake
reservoirs
rivers
methane emissons
China
