关键词: 水系特征, 黑河, 祁连山

Abstract: Based on the Horton linear measures,this paper analyzed drainage basin characteristics of the upper reaches of the Heihe river.The tributaries can be divided into 5 orders on the topographic map with the scale of 1:250 000.According to the measuring results,the drainage basin characteristics do not submit to the stream law absolutely.The law of stream numbers can be applicable in this area with higher bifurcation ratio,but the law of stream length does not be applicable.The relationship between the accumulative volume of the averaged stream length and stream order is linear in the semilog paper while the relationship between the total stream length and stream order in the log-log grid.The frequency and density of the stream are positive correlated to local climatic condition.The frequency and density under moist climate are higher than under drought climate while the stream flow is related to local precipitation.The sediment charge is positive correlated to stream dicing.I n the nor th slope of the Qilian Mountain,the sediment of the river is mainly from transverse valleys.

Key words: drainage characteristic, Heihe river, Qilian Mountain