澜沧江源扎那曲莫云段河型判别初步分析

Preliminary Analysis on River Pattern Discrimination of Moyun Reach in Zhanaqu of Lantsang River Source

澜沧江源地处青藏高原唐古拉山北麓,比邻长江南源当曲,人迹罕至。为了进一步认识澜沧江地貌特征、尤其是河流地貌,得出河流地貌演化、河床冲淤演变的一些基础资料,通过实地考察,采集数据与图像,结合现有河型判别方法,对澜沧江西源扎那曲莫云河段的河型进行判别。结果表明:莫云河段河道边界约束较弱、河床稳定性较差,在顺直-弯曲-分汊-游荡的河型分类体系中,各家判别式一致判定莫云河段为游荡河型;在顺直-弯曲-辫状的河型分类体系中,则一致判定为辫状河型;最后结合国内的河流特点和主流分类体系,可以确定莫云河段属于游荡河型。实地考察资料和河型的判别,可为进一步研究澜沧江源的河流地貌提供参考。

Lantsang river source is located in the north Tanggula Mountain of Qinghai-Tibet Plateau,nearby the south source of the Yangtze River,with hardly any human activities. In order to gradually recognize Lantsang river geomorphology and obtain basic data of geomorphology evolution of river,as well as scouring and silting process of riverbed,we carry out in-situ investigation and collect data and images to judge the river pattern of Moyun reach in Zhanaqu river,west source of Lantsang river. The results show that,boundary constraints of Moyun reach are weak with poor stability of riverbed; furthermore,in the classification system of river pattern which consists of 4 kinds,namely straight,meandering,anabranching,and wandering,we uniformly determine the reach is wandering type by using different discriminants; meanwhile,in the classification system of river pattern with 3 kinds,including straight,meandering and braided,we regard the reach as braided type; finally,according to domestic river characteristics and current classification system,we conclude that Moyun reach is wandering type. Field observation data and river pattern discrimination offer reference for further research on the river geomorphology of Lantsang river source.