南昌市大气降水H-O稳定同位素特征及其水汽来源解析  

The Stable H-O Isotope Characteristic of Atmospheric Precipitation and the Moisture Source Tracing in Nanchang City

作　　者：张海发 郑芳文 杨海全[3] ZHANG Haifa;ZHENG Fangwen;YANG Haiquan(Technology Advisory of Pearl water Resources Commission(Guangzhou)Co.,Ltd,Guangzhou 510610,China;College of Hydraulic and Ecological Engineering,Nanchang Institute of Technology College,Nanchang 330099,China;State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China)

机构地区：[1]水利部珠江水利委员会技术咨询(广州)有限公司,广州510610 [2]南昌工程学院水利与生态工程学院,南昌330099 [3]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550081

出　　处：《地球与环境》2023年第2期133-142,共10页Earth and Environment

基　　金：江西省水利厅科技项目(202123YBKT10);国家自然科学基金项目(41273015)。

摘　　要：南昌市位于长江流域中下游,濒临中国第一大淡水湖—鄱阳湖,水文网系发育。为了深入理解南昌市大气降水来源与路径,并为区域水循环研究提供基础数据,本研究于2015~2016年期间采集南昌市93个日降水事件样品,开展降水H-O稳定同位素特征及其影响因素研究,并试图阐明该区域大气降水水汽来源。结果表明:(1)降水δ^(18)O和δ^(2)H值变化范围较大,相对于其它季节春季偏正,不是单一气候因子的制约而是多种因子共同影响的结果;(2)建立的当地大气降水线方程为δ^(2)H=8.03δ^(18)O+12.1,H-O稳定同位素分馏处于相对平衡状态,为区域水循环研究提供可靠的参考线。氘盈余(d-excess)和HYSPLIT模型综合分析进一步表明:夏秋季降水多与东南和西南季风携带的太平洋和印度洋水汽有关,而冬春季降水来源广泛,涉及季风、西风带、极地气流及局地蒸发的水汽。本研究成果有助于完善中国南方大气湿度循环理论,对指导当地水资源管理、防洪减灾有重要的实际意义。Nanchang city is located in the middle and lower reaches of the Yangtze River Basin,it is close to Poyang Lake,the largest freshwater lake in China,with hydrological network well-developed.In order to deeply understand the moisture source and transport of atmospheric precipitation in Nanchang and provide basic data for regional water cycle research,this study collected 93 daily precipitation event samples in Nanchang from 2015 to 2016 to investigate the stable H-O isotope characteristics and influencing factors of precipitation and attempted to clarify the water vapor source of precipitation.The results showed that:(1)the ranges of precipitationδ^(18)O andδ~2H were large,which was more positive in spring than in other seasons,and were not restricted by a single meteorological factor,but resulted from the mutual influences of multiple factors;(2)the local meteoric water line equation wasδ~2H=8.03δ^(18)O+12.1,and the stable H-O isotope fractionations were in relatively balance states,which can provide a reliable reference for the study of regional water cycle.The comprehensive analyses of the d-excess values and HYSPLIT model results further showed that the precipitation in summer and autumn was mostly related to the water vapor in the Pacific and Indian Oceans carried by the southeast and southwest monsoons,while the precipitation in winter and spring came from a wide range of sources,including the water vapor from monsoons,westerly zone,polar airflow and local evaporation.The findings of this study help to complete the theory of the atmospheric moisture cycle in South China and are also of practical significance for local water resource management and flood control and disaster alleviation.

关 键 词：南方都市 大气降水 H-O稳定同位素 HYSPLIT模型 水汽来源 

分 类 号：P426.6[天文地球—大气科学及气象学]