西秦岭地区大气降水氢氧稳定同位素特征  

Stable Hydrogen and Oxygen Isotopes in Precipitation in the Western Qinling Mountains

作　　者：折远洋[1,2,3] 王圣杰 王鹏[2,3] 雷世军 杨磊[1] SHE Yuanyang;WANG Shengjie;WANG Peng;LEI Shijun;YANG Lei(School of History Culture and Tourism,Longnan Teachers College,Longnan 742500,China;School of Geography and Environment,Jiangxi Normal University,Nanchang 330022,China;Key Laboratory of Poyang Lake Wetland and Watershed Research,Ministry of Education,Jiangxi Normal University,Nanchang 330022,China;College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,China;Key Laboratory of Resource Environment and Sustainable Development of Oasis of Gansu Province,Lanzhou 730070,China)

机构地区：[1]陇南师范高等专科学校历史文化与旅游学院,甘肃陇南742500 [2]江西师范大学地理与环境学院,南昌330022 [3]江西师范大学鄱阳湖湿地与流域研究教育部重点实验室,南昌330022 [4]西北师范大学地理与环境科学学院,兰州730070 [5]甘肃省绿洲资源环境与可持续发展重点实验室,兰州730070

出　　处：《地球与环境》2023年第2期143-152,共10页Earth and Environment

基　　金：甘肃省高等学校创新基金项目(2020B-365);甘肃省杰出青年基金项目(20JR10RA112);陇原青年创新创业人才项目(甘组通字[2022]77号);甘肃省教育科学“十四五”规划项目(GS[2021]GHB1956)。

摘　　要：为了明确西秦岭地区大气降水氢氧稳定同位素特征,于2020年1~12月在甘肃陇南收集了109个降水样品,对其氢氧稳定同位素比率的年内变化及其影响因素进行了分析,并结合HYSPLIT模型后向轨迹分析了降水同位素与水汽来源的联系。结果表明:研究区大气降水中δ^(18)O和δ^(2)H加权平均值分别为-11.0‰和-74.1‰,表现出雨季低(δ^(18)O=-11.5‰,δ^(2)H=-79.0‰)而非雨季高(δ^(18)O=-9.0‰,δ^(2)H=-55.1‰)的年内变化特征。局地大气降水线为δ^(2)H=8.1δ^(18)O+14.6,斜率和截距均高于全球大气降水线。降水δ^(18)O呈现一定的降水量效应,温度效应不显著。雨季受季风作用显著,对应着δ^(18)O偏低的降水,西风全年影响该地区但带来的降水有限。本研究有助于提高对西秦岭山区大气降水氢氧稳定同位素演化的认识,明晰降水同位素的影响因素,为现代水文气象和古气候研究提供参考。In order to investigate the basic characteristics of stable hydrogen and oxygen isotopes in precipitation in the Western Qinling Mountains,109 precipitation samples were collected in Longnan of Gansu from January to December 2020.The intra-annual variations of stable hydrogen and oxygen isotope ratios and their influencing factors were analyzed,and the connection between precipitation isotopes and moisture sources were studied using the HYSPLIT model.The results showed that the weighted averages ofδ^(18)O andδ~2H in precipitation were-11.0‰and-74.1‰,respectively.The heavy isotopes in precipitation were depleted in rainy season(δ^(18)O=-11.5‰andδ~2H=-79.0‰)and enriched in non-rainy season(δ^(18)O=-9.0‰andδ~2H=-55.1‰).The local meteoric water line wasδ~2H=8.1δ^(18)O+14.6,and the slope and intercept of this local equation were higher than the global mean.The amount effect was detected forδ^(18)O,and there was no temperature effect.The rainy season with depleted precipitation isotopes was significantly impacted by the monsoon moisture,and the westerlies all year round brought limited precipitation to the study area.This study is helpful to improve the knowledge of precipitation isotopes evolution in the Western Qinling Mountains and to understand the controlling regimes of precipitation isotopes,which may provide references to the modern hydrometeorology and paleoclimate studies.

关 键 词：西秦岭 氢氧稳定同位素 氘盈余 极端降水 水汽来源 

分 类 号：P426.6[天文地球—大气科学及气象学]