西南地区大气降水中氢氧稳定同位素特征与水汽来源

为阐明西南地区稳定同位素与大气降水的关系,对GNIP昆明、贵阳、桂林、成都站点δD和δ18O进行分析,初步建立当地大气降水线方程,并与中国及全国降水线方程进行对比,揭示该降水线方程的特征.研究表明：大气降水稳定同位素组成受到温度、蒸发、水汽源地等多种因素的相互影响,在不同时间有很大差异.西南地区降水中的δ18O值表现出“夏高冬低”的季节特点.d值呈现出降水中过量氘水汽来源不同的特点,贵阳和桂林地区d值表现为“冬高夏低”的季节特点,而昆明和成都地区却与此相反,d值则表现为“夏高冬低”独特的季节性特征.

SOURCES AND STABLE ISOTOPE CHARACTERISTICS OF PRECIPITATION IN SOUTHWEST OF CHINA

To elucidate the relationship between stable isotope and the extreme drought in southwest of China, based on the stable isotope data of the GNIP in Kunming, Guiyang, Guilin and Chengdu site, the precipitation line equation is rough forward and the rule of seasonal change of stable isotopes are discussed. According to researching, the stable isotopic compositions of precipitation exhibit great diversities in different season due to influ- ences of multiple factors, such as monsoon, rainfall amount moisture source and others. The D value showed characteristics of deuterium excess moisture sources in different precipitation. Guiyang and Guilin d values showed high summer and low winter seasonal characteristics, Kunming and Chengdu shows just the opposite, d value is manifested in high summer and winter seasonal low unique characteristics, explained during the winter and summer monsoon precipitation water district evaporation different conditions.