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对准噶尔盆地东南缘降水和土壤水稳定氢、氧同位素组成(δ18 O和δD)进行了测定,分析了降水中δ18 O和δD值的季节变化规律、表层土壤水中δ18 O和δD值对降水脉冲的动态响应以及不同深度土壤水中δ18 O和δD值的变化特征。结果表明:该区域大气降水线为δD=7.691δ18 O+4.606;降水与表层土壤水中δ18 O和δD值表现出明显的季节变化特征;表层土壤水中δ18 O和δD值、质量含水量对降水脉冲响应显著,且不同量级的降水导致不同程度的响应。利用LSD法对0~300cm土层内土壤水中δ18 O和δD值进行多重比较分析,可将土壤在垂直方向上分为3层,表层(0~50cm)土壤水分活跃,稳定同位素值随深度的增加而迅速减小;中间层(50~180cm)土壤水分相对活跃,既受到降水入渗和蒸发作用的影响,也有地下水的补给;深层(180~300cm)水分来源稳定,土壤水中δ18 O和δD值基本不变。
The precipitation and stable isotope compositions of δ18O and δD in the southeastern Junggar basin were measured, and the seasonal variations of δ18O and δD in precipitation were analyzed. The δ18O and δD values in surface soil water were positively correlated with the precipitation pulse The dynamic response of δ18O and δD values in soil water at different depths. The results show that the atmospheric precipitation line in this area is δD = 7.691δ18 O + 4.606. The δ18O and δD values in precipitation and surface soil water show obvious seasonal variation. The δ18O and δD values in the surface soil water and the mass water content have positive influence on the precipitation pulse The response is significant, and different levels of precipitation lead to varying degrees of response. LSD analysis of δ18O and δD values in soil water from 0 ~ 300cm depth shows that the soil can be divided into three layers in the vertical direction and the soil moisture in the surface layer (0 ~ 50cm) is active. The stable isotope values vary with the depth (180 ~ 300cm), the source of water in the deep layer (180 ~ 300cm) was stable, the δ18O and δD in soil water The value of the same.