成都地区大气降水稳定同位素组成反应的气候特征

分析了1986-1998年成都地区大气降水的稳定同位素组成。夏季降水的δD和δ^18O值比冬季降水轻，反映了季风气候的降水特点。成都地区的大气降水线方程是：δD=1．42＋7．530δ^18O，与全球和中国降水线方程相比，表明了成都地区的蒸发程度稍大于降雨，说明成都地区大气降水的不平衡蒸发程度弱，反映了海洋性气候特征。成都地区大气降水δ^18O与降雨量、温度和水汽压之间都是负相关关系。但是降雨量对大气降水δ^18O的影响最大。

Stable Isotope Compositions for Meteoric Water from Chengdu and Their Implication of Climate

Isotopic compositions for meteoric water from Chengdu during 1986-1998 are analyzed. δ D and δ^18O values of precipitation in summer are much lighter than those of precipitation in winter which is characteristic of monsoon climate. Meteoric water line for Chengdu is： δD = 1.42＋7.530δ^18O. The intercept and the slope are low compared with global and China meteoric water line which reflects the unbalance condition of precipitation. Excess deuterium is relatively small which shows that unbalance condition of precipitation in evaporation and agglomeration was faint. This is characteristic of oceanic climate. δ^18O for precipitation is in positive correlation with rainfall, temperature and water press, however, rainfall is the most important factor that works on δ^18O for precipitation.