快速城市化区河流温室气体排放的时空特征及驱动因素
|
摘要
河流是大气温室气体重要的排放源,近十多年来全球城市化导致河流生态系统各要素发生改变,对河流水体温室气体排放产生影响.为研究快速城市化区不同土地利用方式下河流温室气体排放的时空特征及其影响因素,采用薄边界层模型法,于2014年9月(秋季)和12月(冬季)及2015年3月(春季)和6月(夏季)的晴天对重庆市区内梁滩河干、支流水体pCO_2、CH_4、N_2O溶存浓度进行监测.结果表明,梁滩河干、支流水体pCO_2范围为(23. 38±34. 89)～(1395. 33±55. 45) Pa、CH_4溶存浓度范围(65. 09±28. 09)～(6 021. 36±94. 36) nmol·L~(-1)、N_2O溶存浓度范围为(29. 47±5. 16)～(510. 28±18. 34)nmol·L~(-1); CO_2、CH_4和N_2O排放通量分别为-6. 1～786. 9、0. 31～27. 62和0. 06～1. 08 mmol·(m~2·d)~(-1);流域水体温室气体浓度空间格局与快速城市化带来的污染负荷空间梯度吻合,干流温室气体浓度与通量从上游向下游均呈先增加后降低,在城市化速度最快的中游出现峰值,其中城市河段CO_2和CH_4浓度约为非城市河段的2倍,同时支流水体自上游农业区向下游城市区呈显著增加;由于受到降雨、温度、外源输入的综合影响,河流CO_2排放通量呈秋季>冬季>夏季>春季的季节模式,CH_4排放通量春季最高夏季最低,N_2O排放通量季节差异不显著.流域水体碳、氮含量均较高,水体CO_2的产生和排放不受生源要素限制,但受水温、pH、DO、叶绿素a等生物代谢因子影响; CH_4的产生和排放受水体碳、氮、磷含量和外源污水输入的共同驱动; N_2O的产生和排放主要受高N_2O浓度的城市污水排放影响.本研究认为流域快速城市化加快了河流水体温室气体排放,形成排放热源,因此城市河流温室气体排放对全球河流排放通量的贡献可能被忽视,在未来研究中应受到更多关注.
Rivers play an important role in greenhouse gas emissions. Over the past decade,because of global urbanization trends,rapid land use changes have led to changes in river ecosystems that have had a stimulating effect on the greenhouse gas production and emissions. Presently,there is an urgent need for assessments of the greenhouse gas concentrations and emissions in watersheds.Therefore,this study was designed to evaluate river-based greenhouse gas emissions and their spatial-temporal features as well as possible impact factors in a rapidly urbanizing area. The specific objectives were to investigate how river greenhouse gas concentrations and emission fluxes are responding to urbanization in the Liangtan River,which is not only the largest sub-basin but also the most polluted one in Chongqing City. The thin layer diffusion model method was used to monitor year-round concentrations of p CO_2,CH_4,and N_2O in September and December 2014,and March and June 2015. The p CO_2 range was(23. 38 ± 34. 89)-(1 395. 33 ± 55. 45)Pa,and the concentration ranges of CH_4 and N_2O were(65. 09 ± 28. 09)-(6 021. 36 ± 94. 36) nmol·L~(-1) and(29. 47 ± 5. 16)-(510. 28 ± 18. 34) nmol·L~(-1),respectively. The emission fluxes of CO_2,CH_4,and N_2O,which were calculated based on the method of wind speed model estimations,were-6. 1-786. 9,0. 31-27. 62,and 0. 06-1. 08 mmol·(m~2·d)~(-1),respectively. Moreover,the CO_2 and CH_4 emissions displayed significant spatial differences,and these were roughly consistent with the pollution load gradient. The greenhouse gas concentrations and fluxes of trunk streams increased and then decreased from upstream to downstream,and the highest value was detected at the middle reaches where the urbanization rate is higher than in other areas and the river is seriously polluted. As for branches, the greenhouse gas concentrations and fluxes increased significantly from the upstream agricultural areas to the downstream urban areas. The CO_2 fluxes followed a seasonal pattern,with the highest CO_2 emission values observed in autumn,then successively winter,summer,and spring. The CH_4 fluxes were the highest in spring and the lowest in summer,while N_2O flux seasonal patterns were not significant. Because of the high carbon and nitrogen loads in the basin,the CO_2 products and emissions were not restricted by biogenic elements,but levels were found to be related to important biological metabolic factors such as the water temperature,p H,DO,and chlorophyll a. The carbon,nitrogen,and phosphorus content of the water combined with sewage input influenced the CH_4 products and emissions. Meanwhile,N_2O production and emissions were mainly found to be driven by urban sewage discharge with high N_2O concentrations. Rapid urbanization accelerated greenhouse gas emissions from the urban rivers,so that in the urban reaches,CO_2/CH_4 fluxes were twice those of the non-urban reaches,and all over the basin N_2O fluxes were at a high level.These findings illustrate how river basin urbanization can change aquatic environments and aggravate allochthonous pollution inputs such as carbon,nitrogen,and phosphorus,which in turn can dramatically stimulate river-based greenhouse gas production and emissions;meanwhile,spatial and temporal differences in greenhouse gas emissions in rivers can lead to the formation of emission hotspots.
Rivers play an important role in greenhouse gas emissions. Over the past decade,because of global urbanization trends,rapid land use changes have led to changes in river ecosystems that have had a stimulating effect on the greenhouse gas production and emissions. Presently,there is an urgent need for assessments of the greenhouse gas concentrations and emissions in watersheds.Therefore,this study was designed to evaluate river-based greenhouse gas emissions and their spatial-temporal features as well as possible impact factors in a rapidly urbanizing area. The specific objectives were to investigate how river greenhouse gas concentrations and emission fluxes are responding to urbanization in the Liangtan River,which is not only the largest sub-basin but also the most polluted one in Chongqing City. The thin layer diffusion model method was used to monitor year-round concentrations of p CO_2,CH_4,and N_2O in September and December 2014,and March and June 2015. The p CO_2 range was(23. 38 ± 34. 89)-(1 395. 33 ± 55. 45)Pa,and the concentration ranges of CH_4 and N_2O were(65. 09 ± 28. 09)-(6 021. 36 ± 94. 36) nmol·L~(-1) and(29. 47 ± 5. 16)-(510. 28 ± 18. 34) nmol·L~(-1),respectively. The emission fluxes of CO_2,CH_4,and N_2O,which were calculated based on the method of wind speed model estimations,were-6. 1-786. 9,0. 31-27. 62,and 0. 06-1. 08 mmol·(m~2·d)~(-1),respectively. Moreover,the CO_2 and CH_4 emissions displayed significant spatial differences,and these were roughly consistent with the pollution load gradient. The greenhouse gas concentrations and fluxes of trunk streams increased and then decreased from upstream to downstream,and the highest value was detected at the middle reaches where the urbanization rate is higher than in other areas and the river is seriously polluted. As for branches, the greenhouse gas concentrations and fluxes increased significantly from the upstream agricultural areas to the downstream urban areas. The CO_2 fluxes followed a seasonal pattern,with the highest CO_2 emission values observed in autumn,then successively winter,summer,and spring. The CH_4 fluxes were the highest in spring and the lowest in summer,while N_2O flux seasonal patterns were not significant. Because of the high carbon and nitrogen loads in the basin,the CO_2 products and emissions were not restricted by biogenic elements,but levels were found to be related to important biological metabolic factors such as the water temperature,p H,DO,and chlorophyll a. The carbon,nitrogen,and phosphorus content of the water combined with sewage input influenced the CH_4 products and emissions. Meanwhile,N_2O production and emissions were mainly found to be driven by urban sewage discharge with high N_2O concentrations. Rapid urbanization accelerated greenhouse gas emissions from the urban rivers,so that in the urban reaches,CO_2/CH_4 fluxes were twice those of the non-urban reaches,and all over the basin N_2O fluxes were at a high level.These findings illustrate how river basin urbanization can change aquatic environments and aggravate allochthonous pollution inputs such as carbon,nitrogen,and phosphorus,which in turn can dramatically stimulate river-based greenhouse gas production and emissions;meanwhile,spatial and temporal differences in greenhouse gas emissions in rivers can lead to the formation of emission hotspots.
引文
[1] Cole J J,Prairie Y T,Caraco N F,et al. Plumbing the global carbon cycle:Integrating Inland waters into the terrestrial carbon budget[J]. Ecosystems,2007,10(1):172-185.
[2] Butman D,Raymond P A. Significant efflux of carbon dioxide from streams and rivers in the United States[J]. Nature Geoscience,2011,4(4):839-842.
[3] Striegl R G,Dornblaser M M,Mc Donald C P,et al. Carbon dioxide and methane emissions from the Yukon River system[J].Global Biogeochemical Cycles,2012,26(4):GB0E05.
[4] Meybeck M. Carbon,nitrogen,and phosphorus transport by world rivers[J]. American Journal of Science,1982,282(4):401-450.
[5] Cole J J,Caraco N F,Kling G W,et al. Carbon dioxide supersaturation in the surface waters of lakes[J]. Science,1994,265(5178):1568-1570.
[6] Kroeze C,Dumont E,Seitzinger S P. New estimates of global emissions of N2O from rivers and estuaries[J]. Environmental Sciences,2005,2(2-3):159-165.
[7] Soued C,Del Giorgio P A,Maranger R. Nitrous oxide sinks and emissions in boreal aquatic networks in Québec[J]. Nature Geoscience,2015,9(2):116-120.
[8] Raymond P A,Hartmann J,Lauerwald R,et al. Global carbon dioxide emissions from inland waters[J]. Nature,2013,503(7476):355-359.
[9] Stanley E H,Casson N J,Christel S T,et al. The ecology of methane in streams and rivers:patterns,controls,and global significance[J]. Ecological Monographs,2016,86(2):146-171.
[10] Rosamond M S,Thuss S J,Schiff S L. Dependence of riverine nitrous oxide emissions on dissolved oxygen levels[J]. Nature Geoscience,2012,5(10):715-718.
[11] Meyer J L,Paul M J,Taulbee W K. Stream ecosystem function in urbanizing landscapes[J]. Journal of the North American Benthological Society,2005,24(3):602-612.
[12] Johnson L,Richards C,Host G,et al. Landscape influences on water chemistry in Midwestern stream ecosystems[J]. Freshwater Biology,1997,37(1):193-208.
[13] Jordan T E, Correll D L, Weller D E. Relating nutrient discharges from watersheds to land use and streamflow variability[J]. Water Resources Research,1997,33(11):2579-2590.
[14] Kaushal S S,Delaney-Newcomb K,Findlay S E G,et al.Longitudinal patterns in carbon and nitrogen fluxes and stream metabolism along an urban watershed continuum[J].Biogeochemistry,2014,121(1):23-44.
[15] Beaulieu J J,Tank J L,Hamilton S K,et al. Nitrous oxide emission from denitrification in stream and river networks[J].Proceedings of the National Academy of Sciences of the United States of America,2011,108(1):214-219.
[16] Wang D Q,Chen Z L,Sun W W,et al. Methane and nitrous oxide concentration and emission flux of Yangtze Delta plain river net[J]. Science in China Series B:Chemistry,2009,52(5):652-661.
[17] Wang X F,He Y X,Yuan X Z,et al. p CO2and CO2fluxes of the metropolitan river network in relation to the urbanization of Chongqing, China[J]. Journal of Geophysical Research:Biogeosciences,2017,122(3):470-486.
[18] Beaulieu J J, Shuster W D, Rebholz J A. Nitrous oxide emissions from a large,impounded river:the Ohio River[J].Environmental Science&Technology,2010,44(19):7527-7533.
[19] Nirmal R A,Barnes J,Ramesh R,et al. Methane and nitrous oxide fluxes in the polluted Adyar River and estuary,SE India[J]. Marine Pollution Bulletin,2008,56(12):2043-2051.
[20] Stow C A,Walker J T,Cardoch L,et al. N2O emissions from streams in the Neuse river watershed, North Carolina[J].Environmental Science&Technology,2005,39(18):6999-7004.
[21]常思琦,王东启,俞琳,等.上海城市河流温室气体排放特征及其影响因素[J].环境科学研究,2015,28(9):1375-1381.Chang S Q,Wang D Q,Yu L,et al. Greenhouse gas emission characteristics from urban rivers in Shanghai[J]. Research of Environmental Sciences,2015,28(9):1375-1381.
[22] Yu Z J,Deng H G,Wang D Q,et al. Nitrous oxide emissions in the Shanghai river network:implications for the effects of urban sewage and IPCC methodology[J]. Global Change Biology,2013,19(10):2999-3010.
[23] Hu B B,Wang D Q,Zhou J,et al. Greenhouse gases emission from the sewage draining rivers[J]. Science of the Total Environment,2018,612:1454-1462.
[24] Wang D Q,Tan Y J,Yu Z J,et al. Nitrous oxide production in river sediment of highly urbanized area and the effects of water quality[J]. Wetlands,2015,35(6):1213-1223.
[25] Liu X L,Bai L,Wang Z L,et al. Nitrous oxide emissions from river network with variable nitrogen loading in Tianjin,China[J]. Journal of Geochemical Exploration,2015,157:153-161.
[26] He Y X,Wang X F,Chen H,et al. Effect of watershed urbanization on N2O emissions from the Chongqing metropolitan river network, China[J]. Atmospheric Environment,2017,171:70-81.
[27]国家环境保护总局.水和废水监测分析方法[M].(第四版).北京:中国环境科学出版社,2002.
[28] Yao G R,Gao Q Z,Wang Z G,et al. Dynamics of CO2partial pressure and CO2outgassing in the lower reaches of the Xijiang River,a subtropical monsoon river in China[J]. Science of the Total Environment,2007,376(1-3):255-266.
[29]袁希功,黄文敏,毕永红,等.香溪河库湾春季p CO2与浮游植物生物量的关系[J].环境科学,2013,34(5):1754-1760.Yuan X G,Huang W M,Be Y H,et al. Relationship between p CO2and algal biomass in Xiangxi bay in Spring[J].Environmental Science,2013,34(5):1754-1760.
[30] Raymond P A,Cole J J. Gas exchange in rivers and estuaries:Choosing a gas transfer velocity[J]. Estuaries,2001,24(2):312-317.
[31] Ward B,Wanninkhof R,Mcgillis W R,et al. Biases in the airsea flux of CO2resulting from ocean surface temperature gradients[J]. Journal of Geophysical Research:Oceans,2004,109(C8):C08S08.
[32] Marescaux A,Thieu V,Garnier J. Carbon dioxide,methane and nitrous oxide emissions from the human-impacted Seine watershed in France[J]. Science of the Total Environment,2018,643:247-259.
[33] Burgos M,Sierra A,Ortega T,et al. Anthropogenic effects on greenhouse gas(CH4and N2O)emissions in the Guadalete River Estuary(SW Spain)[J]. Science of the Total Environment,2015,503-504:179-189.
[34]胡蓓蓓,谭永洁,王东启,等.冬季平原河网水体溶存甲烷和氧化亚氮浓度特征及排放通量[J].中国科学:化学,2013,43(7):919-929.Hu B B,Tan Y J,Wang D Q,et al. Methane and nitrous oxide dissolved concentration and emission flux of plain river network in winter[J]. Scientia Sinica Chimica,2013,43(7):919-929.
[35]谭永洁.上海市河流沉积物温室气体的排放与产生机制[D].上海:华东师范大学,2014.Tang Y J. The greenhouse gases emission and production mechanism from river sediment in Shanghai[D]. Shanghai:East China Normal University,2014.
[36] Li S Y,Lu X X,He M,et al. Daily CO2partial pressure and CO2outgassing in the upper Yangtze River basin:A case study of the Longchuan River,China[J]. Journal of Hydrology,2012,466-467:141-150.
[37] Garnier J,Vilain G,Silvestre M,et al. Budget of methane emissions from soils, livestock and the river network at the regional scale of the Seine basin(France)[J]. Biogeochemistry,2013,116(1-3):199-214.
[38] KonéY J M,Abril G,Delille B,et al. Seasonal variability of methane in the rivers and lagoons of Ivory Coast(West Africa)[J]. Biogeochemistry,2010,100(1-3):21-37.
[39] Judd S,Van Den Broeke L J P,Shurair M,et al. Algal remediation of CO2and nutrient discharges:A review[J]. Water Research,2015,87:356-366.
[40] Wang F S,Wang Y C. Human impact on historical change of CO2degassing flux in the Changjiang River,China[J]. Chinese Journal of Geochemistry,2006,25(S1):277.
[41]秦宇,张宇阳,李哲,等.三峡澎溪河水华期间水体CH4浓度及其通量变化特征初探[J].环境科学,2018,39(4):1578-1588.Qin Y,Zhang Y Y,Li Z,et al. CH4fluxes during the algal bloom in the Pengxi river[J]. Environmental Science,2018,39(4):1578-1588.
[42] Yang L B,Lei K. Effects of land use on the concentration and emission of nitrous oxide in nitrogen-enriched rivers[J].Environmental Pollution,2018,238:379-388.
[43] Singh S N,Kulshreshtha K,Agnihotri S. Seasonal dynamics of methane emission from wetlands[J]. Chemosphere-Global Change Science,2000,2(1):39-46.
[44]黄文敏,朱孔贤,赵玮,等.香溪河秋季水-气界面温室气体通量日变化观测及影响因素分析[J].环境科学,2013,34(4):1270-1276.Huang W M,Zhu K X,Zhao W,et al. Diurnal changes in greenhouse gases at water-air interface of Xiangxi River in autumn and their influencing factors[J]. Environmental Science,2013,34(4):1270-1276.
[45] Tremblay A, Schetagne R. The relationship between water quality and greenhouse gas emissions in reservoirs[J].International Journal on Hydropower&Dams,2006,13(1):103-107.
[46] Zhai W D,Dai M H,Cai W J,et al. High partial pressure of CO2and its maintaining mechanism in a subtropical estuary:The Pearl River estuary,China[J]. Marine Chemistry,2005,93(1):21-32.
[47] Wang X F,He Y X,Yuan X Z,et al. Greenhouse gases concentrations and fluxes from subtropical small reservoirs in relation with watershed urbanization[J]. Atmospheric Environment,2017,154:225-235.
[48] Bodelier P L,Steenbergh A K. Interactions between methane and the nitrogen cycle in light of climate change[J]. Current Opinion in Environmental Sustainability,2014,10(9-10):26-36.
[49] Khalil M I,Baggs E M. CH4oxidation and N2O emissions at varied soil water-filled pore spaces and headspace CH4concentrations[J]. Soil Biology and Biochemistry,2005,37(10):1785-1794.
[50] Yang H, Andersen T, Drsch P, et al. Greenhouse gas metabolism in Nordic boreal lakes[J]. Biogeochemistry,2015,126(1-2):211-225.
[51]周兴.南京市受污染水体甲烷和氧化亚氮排放研究[D].南京:南京信息工程大学大气物理学院,2012.Zhou X. Study on methane and nitrous oxide emissions from polluted water in Nanjing[D]. Nanjing:Nanjing University of Information Science&Technology,2012.
[52] Canfield D E,Glazer A N,Falkowski P G. The evolution and future of Earth's nitrogen cycle[J]. Science, 2010, 330(6001):192-196.
[53] Liikanen A,Martikainen P J. Effect of ammonium and oxygen on methane and nitrous oxide fluxes across sediment-water interface in a eutrophic lake[J]. Chemosphere,2003,52(8):1287-1293.
[54] Crawford J T,Striegl R G,Wickland K P,et al. Emissions of carbon dioxide and methane from a headwater stream network of interior Alaska[J]. Journal of Geophysical Research:Biogeosciences,2013,118(2):482-494.
[55] Richey J E,Melack J M,Aufdenkampe A K,et al. Outgassing from Amazonian rivers and wetlands as a large tropical source of atmospheric CO2[J]. Nature,2002,416(6881):617-620.
[56] Teodoru C R,Del Giorgio P A,Prairie Y T,et al. Patterns in p CO2in boreal streams and rivers of northern Quebec,Canada[J]. Global Biogeochemical Cycles,2009,23(2):GB2012.
[57]赵炎,曾源,吴炳方,等.三峡水库香溪河支流水域温室气体排放通量观测[J].水科学进展,2011,22(4):546-553.Zhao Y,Zeng Y,Wu B F,et al. Observation on greenhouse gas emissions from Xiangxi River in Three Gorges Region[J].Advances in Water Science,2011,22(4):546-553.
[58] Qu B,Aho K S,Li C L,et al. Greenhouse gases emissions in rivers of the Tibetan Plateau[J]. Scientific Reports,2017,7:165-173.
[2] Butman D,Raymond P A. Significant efflux of carbon dioxide from streams and rivers in the United States[J]. Nature Geoscience,2011,4(4):839-842.
[3] Striegl R G,Dornblaser M M,Mc Donald C P,et al. Carbon dioxide and methane emissions from the Yukon River system[J].Global Biogeochemical Cycles,2012,26(4):GB0E05.
[4] Meybeck M. Carbon,nitrogen,and phosphorus transport by world rivers[J]. American Journal of Science,1982,282(4):401-450.
[5] Cole J J,Caraco N F,Kling G W,et al. Carbon dioxide supersaturation in the surface waters of lakes[J]. Science,1994,265(5178):1568-1570.
[6] Kroeze C,Dumont E,Seitzinger S P. New estimates of global emissions of N2O from rivers and estuaries[J]. Environmental Sciences,2005,2(2-3):159-165.
[7] Soued C,Del Giorgio P A,Maranger R. Nitrous oxide sinks and emissions in boreal aquatic networks in Québec[J]. Nature Geoscience,2015,9(2):116-120.
[8] Raymond P A,Hartmann J,Lauerwald R,et al. Global carbon dioxide emissions from inland waters[J]. Nature,2013,503(7476):355-359.
[9] Stanley E H,Casson N J,Christel S T,et al. The ecology of methane in streams and rivers:patterns,controls,and global significance[J]. Ecological Monographs,2016,86(2):146-171.
[10] Rosamond M S,Thuss S J,Schiff S L. Dependence of riverine nitrous oxide emissions on dissolved oxygen levels[J]. Nature Geoscience,2012,5(10):715-718.
[11] Meyer J L,Paul M J,Taulbee W K. Stream ecosystem function in urbanizing landscapes[J]. Journal of the North American Benthological Society,2005,24(3):602-612.
[12] Johnson L,Richards C,Host G,et al. Landscape influences on water chemistry in Midwestern stream ecosystems[J]. Freshwater Biology,1997,37(1):193-208.
[13] Jordan T E, Correll D L, Weller D E. Relating nutrient discharges from watersheds to land use and streamflow variability[J]. Water Resources Research,1997,33(11):2579-2590.
[14] Kaushal S S,Delaney-Newcomb K,Findlay S E G,et al.Longitudinal patterns in carbon and nitrogen fluxes and stream metabolism along an urban watershed continuum[J].Biogeochemistry,2014,121(1):23-44.
[15] Beaulieu J J,Tank J L,Hamilton S K,et al. Nitrous oxide emission from denitrification in stream and river networks[J].Proceedings of the National Academy of Sciences of the United States of America,2011,108(1):214-219.
[16] Wang D Q,Chen Z L,Sun W W,et al. Methane and nitrous oxide concentration and emission flux of Yangtze Delta plain river net[J]. Science in China Series B:Chemistry,2009,52(5):652-661.
[17] Wang X F,He Y X,Yuan X Z,et al. p CO2and CO2fluxes of the metropolitan river network in relation to the urbanization of Chongqing, China[J]. Journal of Geophysical Research:Biogeosciences,2017,122(3):470-486.
[18] Beaulieu J J, Shuster W D, Rebholz J A. Nitrous oxide emissions from a large,impounded river:the Ohio River[J].Environmental Science&Technology,2010,44(19):7527-7533.
[19] Nirmal R A,Barnes J,Ramesh R,et al. Methane and nitrous oxide fluxes in the polluted Adyar River and estuary,SE India[J]. Marine Pollution Bulletin,2008,56(12):2043-2051.
[20] Stow C A,Walker J T,Cardoch L,et al. N2O emissions from streams in the Neuse river watershed, North Carolina[J].Environmental Science&Technology,2005,39(18):6999-7004.
[21]常思琦,王东启,俞琳,等.上海城市河流温室气体排放特征及其影响因素[J].环境科学研究,2015,28(9):1375-1381.Chang S Q,Wang D Q,Yu L,et al. Greenhouse gas emission characteristics from urban rivers in Shanghai[J]. Research of Environmental Sciences,2015,28(9):1375-1381.
[22] Yu Z J,Deng H G,Wang D Q,et al. Nitrous oxide emissions in the Shanghai river network:implications for the effects of urban sewage and IPCC methodology[J]. Global Change Biology,2013,19(10):2999-3010.
[23] Hu B B,Wang D Q,Zhou J,et al. Greenhouse gases emission from the sewage draining rivers[J]. Science of the Total Environment,2018,612:1454-1462.
[24] Wang D Q,Tan Y J,Yu Z J,et al. Nitrous oxide production in river sediment of highly urbanized area and the effects of water quality[J]. Wetlands,2015,35(6):1213-1223.
[25] Liu X L,Bai L,Wang Z L,et al. Nitrous oxide emissions from river network with variable nitrogen loading in Tianjin,China[J]. Journal of Geochemical Exploration,2015,157:153-161.
[26] He Y X,Wang X F,Chen H,et al. Effect of watershed urbanization on N2O emissions from the Chongqing metropolitan river network, China[J]. Atmospheric Environment,2017,171:70-81.
[27]国家环境保护总局.水和废水监测分析方法[M].(第四版).北京:中国环境科学出版社,2002.
[28] Yao G R,Gao Q Z,Wang Z G,et al. Dynamics of CO2partial pressure and CO2outgassing in the lower reaches of the Xijiang River,a subtropical monsoon river in China[J]. Science of the Total Environment,2007,376(1-3):255-266.
[29]袁希功,黄文敏,毕永红,等.香溪河库湾春季p CO2与浮游植物生物量的关系[J].环境科学,2013,34(5):1754-1760.Yuan X G,Huang W M,Be Y H,et al. Relationship between p CO2and algal biomass in Xiangxi bay in Spring[J].Environmental Science,2013,34(5):1754-1760.
[30] Raymond P A,Cole J J. Gas exchange in rivers and estuaries:Choosing a gas transfer velocity[J]. Estuaries,2001,24(2):312-317.
[31] Ward B,Wanninkhof R,Mcgillis W R,et al. Biases in the airsea flux of CO2resulting from ocean surface temperature gradients[J]. Journal of Geophysical Research:Oceans,2004,109(C8):C08S08.
[32] Marescaux A,Thieu V,Garnier J. Carbon dioxide,methane and nitrous oxide emissions from the human-impacted Seine watershed in France[J]. Science of the Total Environment,2018,643:247-259.
[33] Burgos M,Sierra A,Ortega T,et al. Anthropogenic effects on greenhouse gas(CH4and N2O)emissions in the Guadalete River Estuary(SW Spain)[J]. Science of the Total Environment,2015,503-504:179-189.
[34]胡蓓蓓,谭永洁,王东启,等.冬季平原河网水体溶存甲烷和氧化亚氮浓度特征及排放通量[J].中国科学:化学,2013,43(7):919-929.Hu B B,Tan Y J,Wang D Q,et al. Methane and nitrous oxide dissolved concentration and emission flux of plain river network in winter[J]. Scientia Sinica Chimica,2013,43(7):919-929.
[35]谭永洁.上海市河流沉积物温室气体的排放与产生机制[D].上海:华东师范大学,2014.Tang Y J. The greenhouse gases emission and production mechanism from river sediment in Shanghai[D]. Shanghai:East China Normal University,2014.
[36] Li S Y,Lu X X,He M,et al. Daily CO2partial pressure and CO2outgassing in the upper Yangtze River basin:A case study of the Longchuan River,China[J]. Journal of Hydrology,2012,466-467:141-150.
[37] Garnier J,Vilain G,Silvestre M,et al. Budget of methane emissions from soils, livestock and the river network at the regional scale of the Seine basin(France)[J]. Biogeochemistry,2013,116(1-3):199-214.
[38] KonéY J M,Abril G,Delille B,et al. Seasonal variability of methane in the rivers and lagoons of Ivory Coast(West Africa)[J]. Biogeochemistry,2010,100(1-3):21-37.
[39] Judd S,Van Den Broeke L J P,Shurair M,et al. Algal remediation of CO2and nutrient discharges:A review[J]. Water Research,2015,87:356-366.
[40] Wang F S,Wang Y C. Human impact on historical change of CO2degassing flux in the Changjiang River,China[J]. Chinese Journal of Geochemistry,2006,25(S1):277.
[41]秦宇,张宇阳,李哲,等.三峡澎溪河水华期间水体CH4浓度及其通量变化特征初探[J].环境科学,2018,39(4):1578-1588.Qin Y,Zhang Y Y,Li Z,et al. CH4fluxes during the algal bloom in the Pengxi river[J]. Environmental Science,2018,39(4):1578-1588.
[42] Yang L B,Lei K. Effects of land use on the concentration and emission of nitrous oxide in nitrogen-enriched rivers[J].Environmental Pollution,2018,238:379-388.
[43] Singh S N,Kulshreshtha K,Agnihotri S. Seasonal dynamics of methane emission from wetlands[J]. Chemosphere-Global Change Science,2000,2(1):39-46.
[44]黄文敏,朱孔贤,赵玮,等.香溪河秋季水-气界面温室气体通量日变化观测及影响因素分析[J].环境科学,2013,34(4):1270-1276.Huang W M,Zhu K X,Zhao W,et al. Diurnal changes in greenhouse gases at water-air interface of Xiangxi River in autumn and their influencing factors[J]. Environmental Science,2013,34(4):1270-1276.
[45] Tremblay A, Schetagne R. The relationship between water quality and greenhouse gas emissions in reservoirs[J].International Journal on Hydropower&Dams,2006,13(1):103-107.
[46] Zhai W D,Dai M H,Cai W J,et al. High partial pressure of CO2and its maintaining mechanism in a subtropical estuary:The Pearl River estuary,China[J]. Marine Chemistry,2005,93(1):21-32.
[47] Wang X F,He Y X,Yuan X Z,et al. Greenhouse gases concentrations and fluxes from subtropical small reservoirs in relation with watershed urbanization[J]. Atmospheric Environment,2017,154:225-235.
[48] Bodelier P L,Steenbergh A K. Interactions between methane and the nitrogen cycle in light of climate change[J]. Current Opinion in Environmental Sustainability,2014,10(9-10):26-36.
[49] Khalil M I,Baggs E M. CH4oxidation and N2O emissions at varied soil water-filled pore spaces and headspace CH4concentrations[J]. Soil Biology and Biochemistry,2005,37(10):1785-1794.
[50] Yang H, Andersen T, Drsch P, et al. Greenhouse gas metabolism in Nordic boreal lakes[J]. Biogeochemistry,2015,126(1-2):211-225.
[51]周兴.南京市受污染水体甲烷和氧化亚氮排放研究[D].南京:南京信息工程大学大气物理学院,2012.Zhou X. Study on methane and nitrous oxide emissions from polluted water in Nanjing[D]. Nanjing:Nanjing University of Information Science&Technology,2012.
[52] Canfield D E,Glazer A N,Falkowski P G. The evolution and future of Earth's nitrogen cycle[J]. Science, 2010, 330(6001):192-196.
[53] Liikanen A,Martikainen P J. Effect of ammonium and oxygen on methane and nitrous oxide fluxes across sediment-water interface in a eutrophic lake[J]. Chemosphere,2003,52(8):1287-1293.
[54] Crawford J T,Striegl R G,Wickland K P,et al. Emissions of carbon dioxide and methane from a headwater stream network of interior Alaska[J]. Journal of Geophysical Research:Biogeosciences,2013,118(2):482-494.
[55] Richey J E,Melack J M,Aufdenkampe A K,et al. Outgassing from Amazonian rivers and wetlands as a large tropical source of atmospheric CO2[J]. Nature,2002,416(6881):617-620.
[56] Teodoru C R,Del Giorgio P A,Prairie Y T,et al. Patterns in p CO2in boreal streams and rivers of northern Quebec,Canada[J]. Global Biogeochemical Cycles,2009,23(2):GB2012.
[57]赵炎,曾源,吴炳方,等.三峡水库香溪河支流水域温室气体排放通量观测[J].水科学进展,2011,22(4):546-553.Zhao Y,Zeng Y,Wu B F,et al. Observation on greenhouse gas emissions from Xiangxi River in Three Gorges Region[J].Advances in Water Science,2011,22(4):546-553.
[58] Qu B,Aho K S,Li C L,et al. Greenhouse gases emissions in rivers of the Tibetan Plateau[J]. Scientific Reports,2017,7:165-173.