河流分类方法研究及河流形态学概论

Study on river classification method and overview of river morphology science

学术界对河流分类分级分段等展开了充分研究,但缺乏系统分析及统一认识。基于流域、水系和干流河道河流形态3要素,提出了独立与非独立河流分类方法;对世界范围内55条独立河流与长江非独立支流水系分别进行了分类应用研究和综合排序;初步构建了河流形态学。研究成果包括:(1)独立河流遵循河口优先原则,河流形态复杂性可划归为复合流域水系与复杂干流河道;基于河长与流域面积约0.5次方的相关关系,构建了流域特征长度、流域综合面积和河流弯曲指数3个河流形态特性指标。(2)流域综合面积排序世界前十位的河流是亚马孙河、尼罗河、刚果河、鄂毕河、叶尼塞河、长江、勒拿河、密西西比河、尼日尔河、阿穆尔河;归纳总结的长江流域河流水系“谱系”河流数量为1,4,9,24,49,63,374,381。(3)河流形态学包括河流分类、分级及分段“基石”研究和干流河道形态研究。研究河流分类及增设河流形态学可填补河流地貌学与河床演变学之间的研究空白,逐步形成河流“几何(河流形态学)-运动(河床演变学)-动力特性(河流动力学)”的研究体系。

Up to now,the academic community has conducted sufficient researches on river classification and segmentation,but there is still a lack of systematic analysis and unified understanding.In this paper,based on three river morphology elements of watershed basin,drainage network and mainstream channel,independent rivers and non-independent rivers as a method of river classification were firstly proposed.Then,comprehensive lists were ranked respectively for 55 independent rivers worldwide and for non-independent tributaries or drainage networks of the Yangtze River while a pedigree was summarized for all rivers or drainages of the Yangtze River.Finally,the river morphology science was preliminarily established and discussed.The research results were as follows:(1)Independent rivers follow principle of estuary priority while complexity of river morphology can be classified into compound watershed or drainage and complex mainstream channel.Based on approximate 0.5 power correlationship between river length and river basin area,3 characteristic indexes of river morphology,namely river featured length,compositive river basin area and river curved indicator were proposed.(2)By index of compositive river basin area,the top 10 rivers worldwide are Rivers of Amazon,Nile,Congo,Ob,Yenise,Yangtze,Lena,Mississppi,Niger and Amur.While river numbers of summarized pedigree for all rivers or drainages of the Yagtze River are 1,4,9,24,49,63,374 and 581.(3)The river morphology science should include cornerstone researches of river classification,stream-order gradation and river segmentation,and researches on morphology of river channel.Study on river classification and establishment of river morphology science enable to fill researching gap between sciences of river geomorphology and fluvial processes,and gradually form researching system on river features of geometry-kinematics-dynamics corresponding to river morphology,fluvial processes and river mechanics.