甲烷 (CH4) 作为大气中重要的温室气体 , 直接或间接地影响全球气候变化。 于 2009 年 3 月 27 日至 4 月 15 日对海南东部河流 ( 文昌河、文教河、万泉河 ) 、潟湖 ( 八门湾、博鳌、小海和老爷海 ) 等进行了调查 , 采集了表层和部分底层水样 , 对溶解 CH4 浓度进行了测定并初步估算了其水 - 气交换通量。结果表明 , 文昌河、文教河受人为活动影响较大 , 表层 CH4 饱和度较高 , 分别为 ( 60664±25118)% 、 (38582±26339)%, 污水输入、红树林输入和现场产生是其 CH4 的主要来源。 万泉河表层 CH4 饱和度为 ( 9472±5594)% , 现场产生是其水体溶存 CH4 的主要源。 八门湾、博鳌、小海和老爷海潟湖表层水体溶存 CH4 均处于过饱和状态 , 但其饱和度远小于入湖河流 , 分别为 ( 2471±2937)% 、 (5692±3435)% 、 (546±251)% 和 (6878±4635)%, 其中河流输入、地下水和红树林间隙水输入、现场产生是潟湖中 CH4 的主要来源 , 水体中 CH4 的氧化和水 - 气交换是 潟湖中 CH4 的主要汇 。初步 估算出 文昌河和万泉河 CH4 的水 - 气交换通量分别为 5967.0 ±5142.1 和 496.2 ±335.9 μmol·m - 2 ·d - 1 , 八门湾、博鳌、小海和老爷海潟湖的 水 - 气交换通量 分别为 528.7±625.0 、 441.7±473.3 、 26.6±21.6 和 1287.8±1453.3 μmol·m - 2 ·d - 1 。 海南东部河流、潟湖是近岸水体及大气 CH4 的净源。
关键词:
甲烷; 分布; 水-气交换通量; 河流; 潟; 湖
Methane (CH4) is an important greenhouse gas, which can influence the Earth's climate change both directly and indirectly. Distributions and fluxes of CH4 in rivers and lagoons of eastern Hainan were obtained during the survey from March 27th to April 15th in 2009. Surface waters of the three rivers (Wenchang, Wenjiao and Wanquan rivers) were over-saturated in CH4 with respect to atmospheric equilibrium [( 60664±25118)%, (38582±26339)% and (9472±5594)%, respectively ]. Surface waters of the lagoons were also over-saturated in CH4, but at much lower levels than those in the rivers. The dissolved CH4 in the lagoons mainly come from riverine input, inputs from groundwater and fringing mangrove forest, and in-situ production; the main sinks of methane in the lagoons were oxidation and outgassing. The estimated air–water CH4 fl uxes using the RC01 formula of Wenchang and Wanquan rivers were 5967.0 ±5142.1 and 496.2 ±335.9 μmol·m - 2 ·d - 1 , respectively. Air–water CH4 fl uxes of the logoons were 528.7±625.0 , 441.7±473.3 , 26.6±21.6, and 1287.8±1453.3 μmol·m - 2 ·d - 1 for Bamen bay, Bo’ao , Xiaohai, and Laoyehai, respectively. Estuaries and lagoons in eastern Hainan are persistently supersaturated in CH4, which indicates that they are net sources of atmospheric CH4.
IPCC. Climate Change 2001: The Scientific Basis [M]. New York: Cambridge University Press, 2001: 1-881.
IPCC. Climate Change 2007: The Physical Science Basis [M]. New York: Cambridge University Press, 2007: 1-996.
ZHOU HUAIYANG, YIN XIJIE, YANG QUNHUI, et al. Distribution, source and ?ux of methane in the western Pearl River Estuary and northern South China Sea[J]. Marine Chemistry, 2009, 117:21–31.
BANGE H W, BARTELL U H , RAPSOMANIKIS S, et al. Methane in the Baltic and North Seas and a reassessment of the marine emissions of methane[J]. Glob Biogeochem Cycles, 1994, 8:465–480.
张桂玲, 张经. 海洋中溶存甲烷的研究进展[J]. 地球科学进展, 2001, 16(6): 829–835.
MIDDELBURG J J, NIEUWENHUIZE J, IVERSEN N, et al. Methane distribution in European tidal estuaries[J]. Biogeochemistry, 2002, 59:95–119.
BARNES RSK. Coastal lagoons[M]. Cambridge: Cambridge University Press, 1980:1–7.
ZHANG GUILING L, ZHANG JING, LIU SUMIN, et al. Methane in the Changjiang (Yangtze River) Estuary and its adjacent marine area: riverine input, sediment release and atmospheric fluxes[J]. Biogeochemistry, 2008, 91(1): 71–84.
BANGE H W. Nitrous oxide and methane in European coastal waters[J]. Estuar Coast Shelf Sci, 2006, 70(3): 361–374.
KONé Y 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, 100:21–37.
BARTLETT K B, BARTLETT R C, HARRISS R C, et al. Methane emissions along a salt marsh salinity gradient[J]. Biogeochemistry, 1987, 4: 183–202.
HIROTA M, SENGA Y, SEIKE Y, et al. Fluxes of carbon dioxide, methane and nitrous oxide in two contrastive fringing zones of coastal lagoon, Lake Nakaumi, Japan[J]. Chemosphere, 2007, 68 (3):597–603.
MAGENHEIMER J F, MOORE T R, CHUMRA G L, et al. Methane and carbon dioxide ?ux from a macrotidal salt marsh, Bay of Fundy, New Brunswick[J]. Estuaries, 1996, 19 (1): 139–145.
DEBORDE J, ANSCHUTZ P, GUéRIN F, et al. Methane sources, sinks and ?uxes in a temperate tidal Lagoon: The Arcachon lagoon (SW France)[J]. Estuarine, Coastal and Shelf Science, 2010, 89:256–266.
王宝灿, 陈沈良, 龚文平, 等. 海南岛港湾海岸的形成与演变[M]. 北京: 海洋出版社, 2006: 75—112.
陈国强, 高建华, 朱大奎. 海南岛万泉河口海岸动态及其整治对策[J]. 海洋通报, 2004, 23(4): 38–43.
何为, 李春初, 沈汉堃, 等. 海南岛小海潟湖通道治理方案研究[J]. 人民珠江, 2005: 28—34.
张桂玲. 中国近海部分海域溶存甲烷和氧化亚氮的生物地球化学研究[D]. 青岛:中国海洋大学, 2004: 38–40.
WIESENBURG D A, GUINASSO N L. Equilibrium solubilities of methane, carbon monoxide and hydrogen in water and seawater[J]. Journal of Chemical and Engineering Data, 1979, 24(4): 356–360.
RAYMOND P A, COLE J J. Gas exchange in rivers and estuaries: Choosing a gas transfer velocity[J]. Estuaries, 2001, 24(2): 312–317.
WANNINKHOF R. Relationship between wind speed and gas exchange over the ocean[J]. Journal of Geophysical Research, 1992, 97(C5): 7373–7382.
海南省国土环境资源厅. 2008年海南省环境状况公报[EB/OL].(2009-06-05)[2010-3-10]. http://www.hainan.gov. cn/data/news/2009/06/78814/.
李佩佩.黄河口及黄、渤海溶存甲烷和氧化亚氮的分布与释放通量[D]. 青岛: 中国海洋大学, 2010: 24–40.
SMITH L K, LEWIS W M, CHANTON J P, et al. Methane emissions from the Orinoco River ?oodplain, Venezuela[J]. Biogeochemistry, 2000, 51:113–140.
JONES J B, MULHOLLAND P J. In?uence of drainage basin topography and elevation on carbon dioxide and methane supersaturation of stream water[J]. Biogeochemistry, 1998a, 40: 57–72.
赵静. 长江和海南东部典型水体中溶存甲烷和氧化亚氮的分布与释放[D]. 青岛: 中国海洋大学, 2008: 49–62.
GONG WENPING, SHEN JIAN, JIA JIANJUN. The impact of human activities on the flushing properties of a semi-enclosed lagoon: Xiaohai, Hainan, China[J]. Marine Environmental Research, 2008, 65(1): 62–76.