太原地区大气降雨的氢氧同位素特征研究

大气降雨中氢氧同位素特征的研究是利用同位素理论研究水循环的基础。为了研究太原地区大气降雨的水汽来源、当地大气降水线及降雨过程中的蒸发效应,利用观测数据对太原地区大气降雨中氢氧同位素特征进行了分析。结果表明:在当地季风气候的影响下,大气降雨中的同位素组成具有明显的季节性变化;氘盈余值的变化范围较大,说明形成当地降雨的水汽来源区的空气湿度变化较大;研究区降雨主要来源于海洋,当地地表水体的蒸发对当地大气降雨几乎无影响;当地大气降水线的斜率小于全球大气降水线,但大于蒸发线,说明雨滴在降落的过程中发生了一定程度的蒸发。研究结果可为太原地区地表-地下水循环的研究提供一定的依据。

Research on characteristics of hydrogen and oxygen isotopes of precipitation in Taiyuan area

The study on the characteristics of hydrogen and oxygen isotopes of precipitation is the basis of researching water cycle by use of isotopic technology. For the aim of revealing the stream source of rainfall, local meteoric water line and evaporative effect during process of rainfall, the paper analyzed the characteristics of hydrogen and oxygen isotopes in precipitation according to observed data. The results show that contents of isotopes in precipitation possesses remarkable season variation due to the impact of monsoonal climate; the large range of D-excess values indicated that air humidity of water vapor sources area varies in larger range; the precipitation in research area mainly come from ocean.The evaporation of surface water has hardly influence on local rainfall;the slope of Local Meteoric Water Line (LMWL) is less than that of Global Meteoric Water Line(GMWL), but it is larger than Evaporative Line(EL),which indicated rainfall occurred certain evaporation in process of rainfall dropping. The results can provide a basis for the study of circle between groundwater and surface water in this region.