黑河上游水系发育特征分析

对黑河上游山区部分的水系发育特征进行了分析。在1:250 000比例尺的地形图上,黑河河道可以划分为五级。根据Horton的地貌关系统计结果,黑河水系特征不都服从于Horton的河道定律。河道数量定律适用于本地区,但河道分岔比较高。河道长度定律不适用于本地区,在半对数纸上,平均河道长度的累计值与河道级序有较好的直线关系,而河道总长度与级序则呈双对数直线关系。河道频率及河网密度与河谷局地气候呈正相关,湿润气候条件下,河道频率与河网密度较大;反之,干旱气候条件下,河道频率与河网密度较小。但河流的产流则与区域降水量有关。河川径流的泥沙含量与河流切割程度呈正相关,祁连山北坡河流的泥沙主要来源于横向深切河谷。

Analysis on Drainage Basin Characteristics of the Upper Reaches of Heihe River

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. In the north slope of the Qilian Mountain, the sediment of the river is mainly from transverse valleys.