The Primary Analysis of Water-balance in Binggou Basin of Qilian Mountains
Zhang Xuecheng and Yang Zhenniang (Lanzhou Institute of Glaciology and Geocryology; Chinese Academy of Sciences)
Water-balance has been studiedfor three hundred years. It was used usually to evaluate regional evapotranspiration in 1940siand,1930s Recently it has been used for discussion on the problems of climatic changes and water cycle by some specialists such as Gleick. It is becoming interesting for specialists to study water-balance in high altitudes of our country. Based on observation data from 1984 to 1987 in Binggou catchment, the characters of water-balance factors are analysied and the runoff, mathematic model is built in this paper. The result shows that Binggou annual precipitation is about 600-700 mm,and the annual runoff coefficient is between 0.55-0.70, so Binggou catchment is one of steady water resources in semi-arid areas of Hexi region, and the runoff model can be used for practice. Binggou normal annual evapotrdnspiration is about 340 mm, less than those of Babaohe and Heihe area. This shows that there is full water resources in highly altitude region and this area may be further studied and developed.