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应用生态学报 ›› 2020, Vol. 31 ›› Issue (6): 1791-1799.doi: 10.13287/j.1001-9332.202006.020

• 稳定同位素生态学专栏 • 上一篇    下一篇

水汽来源和环境因子对湖南会同大气降水氢氧同位素组成的影响

隋明浈1, 张瑛1, 徐庆1*, 高德强1, 王婷1, 汪思龙2   

  1. 1中国林业科学研究院森林生态环境与保护研究所, 国家林业和草原局森林生态环境重点实验室, 北京 100091;
    2中国科学院沈阳应用生态研究所, 沈阳 110016
  • 收稿日期:2019-12-30 出版日期:2020-06-15 发布日期:2020-06-15
  • 通讯作者: * E-mail: xuqing@caf.ac.cn
  • 作者简介:隋明浈, 女, 1991年生, 博士研究生。主要从事稳定同位素生态学研究。E-mail: cafsmz@163.com
  • 基金资助:
    国家自然科学基金项目(31870716)、中央级公益性科研院所基本科研业务费专项资金重点项目(CAFYBB2017ZB003)和国家重点研发计划项目(2016YFD060020106)资助

Effects of water vapor source and local environmental factors on the hydrogen and oxygen isotopic compositions of precipitation in Huitong, Hunan Province, China

SUI Ming-zhen1, ZHANG Ying1, XU Qing1*, GAO De-qiang1, WANG Ting1, WANG Si-long2   

  1. 1Key Laboratory of Forest Ecology and Environment of the National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China;
    2Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:2019-12-30 Online:2020-06-15 Published:2020-06-15
  • Contact: * E-mail: xuqing@caf.ac.cn
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (31870716), the National Non-profit Institute Research Grant of Chinese Academy of Forestry (CAFYBB2017ZB003) and the National Key Research and Development Program (2016YFD060020106).

摘要: 氘(D)和18O是水中常见的环境示踪剂,研究大气降水氢氧稳定同位素组成是研究区域及全球水循环过程的必要前提。为了揭示降水同位素组成对环境因子的响应机制,本研究在中国科学院会同森林生态实验站收集了2017年5月—2019年8月149次不同量级大气降水样品及环境因子数据,分析该地区大气降水氢氧同位素的时间变化特征,探讨水汽来源和环境因素对降水氢氧稳定同位素组成的影响。结果表明: 湖南会同大气降水线方程为: δD=(7.45±0.17)δ18O+(10.10±1.25) (R2=0.93,P<0.01),斜率比中国及全球大气降水线斜率略低;大气降水中稳定同位素组成与局地环境因子密切相关,并对季风气候中的水汽来源响应敏感,表现为夏季风期间18O和D贫化,冬季风期间18O和D富集;夏季风期间,受到孟加拉湾、南海和西太平洋在夏季风和季风后3种不同气压下远距离海洋水汽的影响,过量氘均值接近全球平均值;冬季风期间,大气降水氢氧同位素值受到远距离西风气团、孟加拉湾退化热带海洋气团、季风前期内陆水汽和局地环境因子的共同作用,大气降水线斜率偏低,过量氘值偏大。

Abstract: Deuterium (D) and oxygen-18 (18O) are common environmental tracers in water. Understanding the isotopic compositions of precipitation is necessary for further studies on local and global water cycling processes. To reveal the mechanism of isotopic compositions of precipitation in subtropical monsoon region in response to environmental changes, we collected 49 precipitation samples and recorded related environmental factors from May 2017 to August 2019 in Huitong field station of Chinese Academy of Sciences in Hunan Province. We analyzed the temporal variations in D and 18O values in precipitation and analyzed the influence of water vapor source and local environmental factor on stable isotopic compositions of precipitation. The local meteoric water line was established as δD=(7.45±0.17)δ18O+(10.10±1.25) (R2=0.93, P<0.01), the slope of which was slightly lower than China’s meteoric water line and the global meteoric line. The D and 18O values of precipitation samples were closely coupled with local meteorological conditions and dominant moisture sources. The 18O and D contents were depleted during summer monsoon season but enriched during winter monsoon season. During the summer monsoon and post-monsoon seasons, precipitation in this area came mainly from the Bay of Bengal, the South China Sea, and the West Pacific at three different types of air pressure, which lead to the similarity of the D-excess value of the precipitation to global average. The lower intercept of meteoric water line and the higher D-excess value for precipitation during the winter monsoon season resulted from moisture from remote westerly air masses, degenerated tropical marine air masses from the Bay of Bengal, and inland moisture in the pre-monsoon period, which were also affected by local environmental factors.