关键词: 玛纳斯湖, 三屯河, 呼图壁河, 河道变迁

Abstract: The changes of river system in the Arid Area are major aspects of env ironmental evolvement and are related to other aspects closely. To research the process of rivers system changes is the first step to study the environmental evolvement of the Arid Area. The watercourse location of Santun River and Hutubi River was reconstructed in different historical periods by re-analysis on historic al materials, historical maps, historical files, being combined with the modern scientific achievements on climatology, hydrology and remote sensing images. The main results are (1) Santun River and Hutubi River belonged to one river system, which was one of inpouring rivers to Manas Lake before 20^thcentury; (2) Santun River and Hutubi River were apart in the first 20 years of 20^thcentury due to the reduction of the two rivers' current and the change of the rivers' courses; (3) all courses of Santun River and Hutubi River were fixed by Human being in the last 50 years; (4) precipitation changes in the north slope of Tianshan Mountain play the main role in the river system changes of Santun River and Hutubi River in the end of 19^thcentury and at the beginning of 20^thcentury; (5) human activiy is the main cause of the river system changes of Santun River and Hutubi River in the last 50 years.

Key words: Manas Lake, Santun River, Hutubi River, river system changes