中国西北地区的小冰期

THE LITTLE ICE AGE OF NORTHWEST CHINA

通过考察、地衣测年、树轮资料、冰岩芯资料、文史资料、及有关公式推算等,对天山和祁连山小冰期的年代、气候、冰川及地表迳流等的变化进行了研究。并同北半球其它地区进行了对比,初步总结了中国西北地区小冰期的基本概况。

The little ice age had begun from early 15 C. to end of 16 C. in Nor- thwest China. In the Northern Hemisphere, the age beginning time of the Little Ice Age postponed from north to south from west to east, and from humid to arid area. In Northwest China, the physical environment has been changing. The annual temperature has risen about 1-1.3℃, precipitation has decreased by 50-78mm, evaporation has incresed by 7%, consequently, the glacier area has shrunk about 21-46%, and the reduction of 14% in runoff resulted from the decrease to less than 10% in meltwater supply pro- portion of rivers. The trend of climate variation is dry-warm since the Li- ttle lce Age.