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应用生态学报 ›› 2018, Vol. 29 ›› Issue (5): 1479-1488.doi: 10.13287/j.1001-9332.201805.028

• 稳定同位素生态学专栏 • 上一篇    下一篇

西北地区降水稳定同位素的云下二次蒸发效应

刘洁遥1,2, 张福平1,2*, 冯起1,3, 李宗省3, 朱艺文1,2, 聂硕1,2, 李玲1,2   

  1. 1陕西师范大学地理科学与旅游学院, 西安 710119;
    2地理学国家级实验教学示范中心(陕西师范大学), 西安 710119;
    3中国科学院西北生态环境资源研究院, 兰州 730000
  • 收稿日期:2017-12-25 出版日期:2018-05-18 发布日期:2018-05-18
  • 通讯作者: * E-mail: zhang_fuping@163.com
  • 作者简介:刘洁遥,女,1993年生,硕士研究生.主要从事生态水文学研究. E-mail: 1145335438@qq.com
  • 基金资助:
    本文由国家科技支撑计划项目(2012BAC08B07)和中央高校基本科研业务费科研发展专项(GK201101002)资助

Influence of below-cloud secondary evaporation on stable isotope composition in precipitation in Northwest China.

LIU Jie-yao1,2, ZHANG Fu-ping1,2*, FENG Qi1,3, LI Zong-xing3, ZHU Yi-wen1,2, NIE Shuo1,2, LI Ling1,2   

  1. 1School of Geography and Tourism, Shaanxi Normal University, Xi’an 710119, China;
    2National Demonstration Center for Experimental Geography Education (Shaanxi Normal University), Xi’an 710119, China;
    3Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2017-12-25 Online:2018-05-18 Published:2018-05-18
  • Contact: * E-mail: zhang_fuping@163.com
  • Supported by:
    This work was supported by the Science and Technology Support Project of China (2012BAC08B07) and Fundamental Research Funds for the Central Universities (GK201101002)

摘要: 利用GNIP提供的我国西北地区的8个站点和本研究的2个站点的降水同位素数据以及相应的气象数据,结合HYSPLIT模型和水滴蒸发模型,分析了我国西北地区降水δ18O和d的时空分布,对该区二次蒸发效应进行了存在性判定与定量讨论,并探讨了二次蒸发效应的敏感因子.结果表明: 夏季风期间,新疆地区δ18O和d值由南向北均走低,陕甘宁地区由南向北,由东向西δ18O值整体上升,d值呈现下降趋势;冬季风期间,西北地区由南到北,由东向西δ18O值整体上逐渐减小,新疆地区d值由南向北升高,陕甘宁地区由南向北d值呈现下降趋势,由东向西有微弱的增大.我国西北地区夏季风时期的大气降水线的斜率、截距(6.80,-0.07)显著低于研究区全年的大气降水线方程的斜率、截距(7.27,3.37)和冬季风时期的大气降水线的斜率、截距(7.46,6.07),表明夏季风期间二次蒸发作用较强.研究区夏季风时期的蒸发比率均值为4.49%,高于冬季风时的3.65%,而黄土高原周边站点冬季风时期的蒸发比率高于夏季风时期,这与黄土高原近年来干旱加剧密不可分.另外,二次蒸发作用的强度随相对湿度、降水量和水汽压的增大而减弱,随温度(大于0 ℃)的升高而增强,但各因子在不同范围时对二次蒸发作用的影响有差异.

Abstract: The precipitation isotope data and meteorological data of eight stations provided by GNIP (Global Network for Isotopes in Precipitation) and two stations from the present study, combined with HYSPLIT model and water droplet evaporation model were used to examine the spatial and temporal distribution of precipitation δ18O and d values in Northwest China. The secondary evaporative effect of existence was evaluated and then quantitatively discussed, with the sensitive factors of secondary evaporative effect being considered. The results showed that during the summer monsoon, the δ18O and d values decreased from south to north in Xinjiang, while the δ18O value increased but d values decreased from south to north and from east to west of Shaanxi-Gansu-Ningxia region. During the winter monsoon, the δ18O value decreased from east to west in whole Northwest region, while the d value increased from south to north in Xinjiang, decreased from south to north and increased slightly from east to west in Shanxi-Gansu-Ningxia. The slope and intercept (6.80, -0.07) of the atmospheric precipitation line in the summer monsoon period was significantly lower than that of annual mean (7.27, 3.37) and winter monsoon period (7.46, 6.07), indicating that the secondary evaporation was stronger during the summer monsoon. The evaporation ratio in the summer monsoon was 4.49%, which was higher than 3.65% in the winter monsoon. However, the evaporation ratio of the winter monsoon was higher than the summer monsoon around of Loess Plateau, which might closely relate to the increasing drought of the Loess Plateau in recent years. Finally, the intensity of secondary evaporation decreased with increasing relative humidity, precipitation and vapor pressure but increased with increasing temperature (greater than 0 ℃). The influences of those factors (humidity, precipitation, temperature and vapor pressure) on the secondary evaporation were dependent on the differences of ranges.