本文研究了乌鲁木齐地区近17年(1986-2002)大气降水的氢氧同位素组成,提出了大气降水线方程为δD=7.21δ^18O+4.50,并与全国及全球降水线方程进行对比,揭示了该降水线方程的特征。研究表明,乌鲁木齐水分来源复杂,主要是西风带输送的海洋水汽和局地的蒸发,大气降水的加权平均^18O与月平均气温相关关系显著,与雨量效应(降水量效应)较相关,降水中温度效应明显,且在一定时期很大程度上其影响掩盖了雨量效应。乌鲁木齐降水中δ^18O的季节变化与温度的季节变化几乎一致,温度是制约降水中稳定同位素变化的主要影响因子。
In this paper, hydrogen and oxygen isotopic compositions of the precipitation in the recent 17 years( from 1986 to 2002)in Urumqi area are studied,and the precipation line equation δD = 7.21δ^18O + 4.50 is brougut forward. Comprision with the national and global equation is made to reveal the characters of this equation. According to the research, prepitation source in Urumqi is complicated, mainly from oceanic vapor and local evaporation. δ^18O of precipitation( monthly means)and average temperature assume prominent correlation. There is notable temperature effect in Urumqi area. It has been observed that the seasonal variations of δ^18O in precipitation are almost consistent with its of air temperature in Urumqi area, which shows that temperature is a main factor controlling the stable isotopic variations in precipitation.