中国西北部高山区多尺度降水稳定同位素的时空变化成因分析  

Assessment of spatial and seasonal variability on multi-scale precipitation isotopes in the high mountains inWestern China

作　　者：张鑫 孙从建[1,2] 周思捷 王诗语[1,2] 陈伟 ZHANG Xin;SUN Congjian;ZHOU Sijie;WANG Shiyu;CHENWei(College of Geography,Shanxi Normal University,Taiyuan 030031,China;Research Center of Ecological Environment in the Middle Reaches of the Yellow River,Shanxi Normal University,Taiyuan 030031,China)

机构地区：[1]山西师范大学地理科学学院,太原030031 [2]山西师范大学黄河中游生态环境研究中心,太原030031

出　　处：《地理研究》2023年第5期1393-1409,共17页Geographical Research

基　　金：国家自然科学基金项目(41901022)。

摘　　要：大气降水氢氧稳定同位素可以指示降水过程的气候环境变化,分析其变化对于研究现在及过去气候条件下的水文循环过程具有重要意义。本研究选取中国西北部典型的天山、昆仑山为研究对象,基于研究区5个高山站点2013—2015年间的353个大气降水样品的δ2H、δ^(18)O分析测试结果,系统分析了不同时间尺度下δ2H与δ^(18)O的时空分布特征及其与环境要素的关系,并结合ERA5数据探讨了其水汽通量及风向特征。结果表明:①研究区大气降水稳定同位素呈现较为显著的时空变化特征,降水δ^(18)O季节上呈现夏高冬低,而空间上呈现北高南低;拟合的区域大气降水线为δ2H=7.74δ^(18)O+5.83(R^(2)=0.98),揭示其降水过程受云下蒸发影响强烈(斜率较低)。②研究区降水δ^(18)O与温度呈现正相关关系,与高程呈现负相关关系,而与降水量间无显著相关关系。③水汽来源的分析结果表明,研究区水汽输送路径主要为西方路径(占比67.37%)、北方路径(17.25%)及西南路径(15.38%);该区域主要的水汽输送来源为西风。本文研究结果对区域水循环认识的提升具有重要作用。Hydrogen and oxygen stable isotopes of atmospheric precipitation can indicate the climatic and environmental changes of precipitation process.The accurate representation of variability of isotopic composition of modern precipitation based on long-term continuous monitoring is vital for interpreting hydrological and climatic processes.It is of great significance to analyze the changes of stable isotopes of atmospheric precipitation for studying the hydrological cycle process under current and past climatic conditions.Based on the measurement ofδ2H andδ^(18)O of 353 precipitation samples from five stations in the Kunlun Mountains and Tianshan Mountains in Western China from 2013 to 2015,the spatial and temporal distribution characteristics ofδ2H andδ^(18)O on multi-scales and their relationship with environmental factors(meteorological controlling factors and geographical position)were analyzed by using the moving average method,and the water vapor flux and wind direction characteristics were analyzed by using ERA5.The results show that:(1)The stable isotopes of atmospheric precipitation in the study area show obvious spatial and temporal variation characteristics,which are higher in summer and lower in winter,whileδ^(18)O is higher in the north and lower in the south.The fitting regional meteoric water line isδ2H=7.74δ^(18)O+5.83(R^(2)=0.98),revealing that its precipitation process is strongly influenced by sub-cloud evaporation(lower slope).(2)The precipitationδ^(18)O in the study area was positively correlated with temperature and negatively correlated with elevation;the effect of rainfall in the study area was not significant.(3)The analysis results of water vapor sources show that the water vapor transport in the study area mainly includes the western path(67.37%),the northern path(17.25%)and the southwestern path(15.38%).The main source of water vapor transport in this region is the westerly wind,which had a stronger influence on the ACA,the southwest monsoon had a major effect on the transport of wat

关 键 词：降水 氢氧稳定同位素 中国西部高山区 时空分布 多尺度 

分 类 号：P426.612[天文地球—大气科学及气象学]