张掖降水同位素及云下二次蒸发影响因素研究  

Study of Precipitation Stable Isotopes and Influencing Factors for Sub-cloud Evaporation at Zhangye

作　　者：张重花 马芬艳 周俊 ZHANG Chonghua;MA Fenyan;ZHOU Jun(Water Resources Department of Gansu Province,Lanzhou 730000,China;College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Water Conservancy Research Institute of Jiuquan,Jiuquan 735000,China)

机构地区：[1]甘肃省水利厅,甘肃兰州730000 [2]兰州理工大学能源与动力工程学院,甘肃兰州730050 [3]甘肃省酒泉市水利科学研究院,甘肃酒泉735000

出　　处：《水文》2025年第2期56-62,共7页Journal of China Hydrology

基　　金：甘肃省水利厅水利技术推广项目“基于梯级水库联合调度的疏勒河流域水旱灾害防治关键技术研究”(甘水建管发〔2021〕87号)。

摘　　要：降水和蒸发是水文循环中重要的环节,降水从云底降落到地面的过程中会发生二次蒸发。由于气温、降水量等水文气象因素的季节变化,导致云下二次蒸发程度和地面降水同位素发生变化。基于张掖站的降水同位素数据以及水文气象数据,在明确当地大气降水同位素变化规律及影响因素的基础上,分析了云下二次蒸发程度及其与水文(降水量)、气象(相对湿度、气温)要素之间的关系,揭示了不同水文气象因素对云下二次蒸发的影响。结果表明:张掖站的大气降水同位素主要受温度的影响,呈现夏季富集、冬季贫化的特点,具有明显的季节变化。当地大气降水线斜率为7.02,低于全球大气降水线,降水在下落过程中受到云下二次蒸发的影响。云下二次蒸发受相对湿度的影响最大,其次为降水量,气温对云下二次蒸发也存在影响。Precipitation and evaporation are important parts of the hydrologic cycle.Raindrop is subjected to sub-cloud evaporation as it descends from the bottom of clouds to the ground.It was changed in the degree of sub-cloud evaporation and precipitation isotopes on the ground with seasonal changes in meteorological factors such as temperature and precipitation.Based on the precipitation isotopes and meteorological data at Zhangye station,this study analyzed the degree of sub-cloud evaporation and its relationship with hydrology(precipitation),meteorological(relative humidity,temperature)elements to reveal the influence of different meteorological factors on sub-cloud evaporation,on the base of clarifying the changes of atmospheric precipitation isotopes and the influencing factors.The results show that the precipitation stable isotopes at Zhangye station are mainly affected by temperature,and characterized by obvious seasonal changes with rich in summer and depleted in winter.The slope of the Local Meteoric Water Line is 7.02,which is lower than that of Global Meteoric Water Line,because the raindrops are affected by the sub-cloud evaporation with falling.Sub-cloud evaporation is most affected by relative humidity,followed by precipitation amount,and air temperature also has an effect on it.

关 键 词：降水同位素 云下二次蒸发 张掖 

分 类 号：P339[天文地球—水文科学]