水汽源区变化对陕西关中降水稳定同位素的影响  

Effect of Moisture Source Variation on Stable Isotopes of Precipitation in Guanzhong Region, Shaanxi Province

作　　者：畅俊斌 吴广涛 元佳飞 郭政昇 CHANG Junbin;WU Guangtao;YUAN Jiafei;GUO Zhengsheng(Shaanxi Geological and Mineral Engineering Geological Brigade 908,Xi'an 710600 China;Shaanxi Key Laboratory of Explorationand Comprehensive Utilization of Mineral Resources,Xi'an 710600 China;College of Geographical Sciences,Shanxi Normal University,Linfen 041000,China)

机构地区：[1]陕西地矿九○八水文地质工程地质大队,陕西西安710600 [2]陕西省矿产资源勘查与综合利用重点实验室,陕西西安710600 [3]山西师范大学地理科学学院,山西临汾041000

出　　处：《水文》2019年第5期71-77,共7页Journal of China Hydrology

基　　金：国家自然科学基金项目(40972154)

摘　　要：基于关中地区7个站点的降水同位素及气象数据,分析了δ18O的时空特征及环境效应,模拟出代表站点的气团运移轨迹,利用向外长波辐射(OLR)数据研究水汽源区变化及对夏半年降水稳定同位素的影响。结果表明:δ18O有着较为明显的季节性变化规律,由春季到冬季逐渐下降,空间分布则呈由东南向西北递减的趋势;大气降水线方程表现出明显的过渡性区位特征,夏半年以降水量效应为主;水汽主要通过西北与东南两个水汽通道输送,青藏高原的热力、动力性质对水源差异产生了较大影响;水汽源区变化与对流层中上部水汽含量场都与稳定同位素特征、水汽运移轨迹有着较强的对应关系,8、9月形成于西太平洋的热带辐合带(ITCZ)使东南季风成为夏季关中地区主要的水汽输送通道。Based on the isotopic values of precipitation from seven stations in Guanzhong region,this paper analyzed the spatial and temporal distribution characteristics and environmental effect,simulated the trajectory of air mass transport in this area,and explored the influence of the changes of the moisture sources and conveying process on stable isotopes of precipitation in summer half year by using OLR technology.The results show that the time variation of δ18O has obvious seasonal variation rule,gradually decline from spring to winter,the trend of spatial distribution is decreasing from southeast to northwest;The meteoric water line shows obvious transitional features,and the precipitation effect is relatively significant in summer half year;The water vapor is transported mainly through the two channels:the northwest and southeast,the thermal and dynamic properties of the Tibetan Plateau have a great influence on the differences of water vapor source in the basin.The variation of moisture sources and water vapor content field in the upper and middle troposphere have a better relationship with stable isotope characteristics,in August and September,ITCZ formed in the Western Pacific become the southeast monsoon water vapor channel mainly in summer in Guanzhong region.

关 键 词：降水同位素 水汽来源 OLR场 ITCZ 关中地区 

分 类 号：P342[天文地球—水文科学]