年楚河流域降水特性

年楚河水汽主要来源于孟加拉湾暖湿气流．年平均降水量３６０ｍｍ左右．降水量地区分布不均．从河口的４３０ｍｍ向上逐渐减少．处于雨影中心区的康马、涅如年降水量小于２４０ｍｍ．降水年内分配不均．年际变化大，全年９２％以上降水集中在６至９月，１１月至３月基本无降水，连续无雨日达２００天．降水同位素（δＤ、δ（１８）Ｏ、Ｔ）反映了年楚河降水变化趋势和水汽来源．     

年楚河流域降水特性

年楚河水汽主要来源于孟加拉湾暖湿气流，年平均降水量３６０ｍｍ左右，降水量地区分布不均，从河口的４３０ｍｍ向上逐渐减少，处于雨影中心区的康马、涅如年降水量小于２４０ｍｍ。     

Study on the water environment and composition of Lhasa River

By measuring and comparing δD, δ18O, and 3H values of different sections in Lhasa River, we can trace its water resource and water environment. We have concluded that the upper reaches of the Lhasa River are mainly supplied by melt-water (with lower 3H value and mineralization degree) and underground water (with lower 3H value and higher mineralization degree). The middle reaches are mainly supplied by rainwater (with higher 3H value and mineralization degree).