山区河流河床结构表征新方法  

A new method of calculating riverbed structure in mountain streams

作　　者：李志威[1,2] 颜旭 潘保柱 余国安 王兆印[5] LI Zhiwei;YAN Xu;PAN Baozhu;YU Guoan;WANG Zhaoyin(School of Hydraulic Engineering,Changsha University of Science &Technology,Changsha410114,China;Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province,Changsha 410114,China;State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China,Xi'an University of Technology,Xi'an 710048,China;Key Laboratory of Water Cycle and Related Land Surface Processes,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]长沙理工大学水利工程学院,湖南长沙410114 [2]水沙科学与水灾害防治湖南省重点实验室,湖南长沙410114 [3]西安理工大学省部共建西北早区生态水利国家重点实验室,陕西西安710048 [4]中国科学院地理科学与资源研究所中国科学院陆地水循环与地表过程重点实验室,北京100101 [5]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《水科学进展》2018年第6期799-809,共11页Advances in Water Science

基　　金：国家自然科学基金资助项目(51622901);湖南省科技重大专项(2018SK1010).

摘　　要：山区河流的河床结构是来水来沙与河床相互作用的产物,对河床阻力及输沙率的计算具有重要意义。为更科学地表征河床结构的细节特征,采用2017年2次考察金沙江小江流域干支流7个河段的地形测量数据,提出河床结构表征的4个新量纲一数(凹凸数、平均凹度、平均凸度和凹凸度)及其计算方法。新参数的计算原理简单而直观,能够从多角度表征河床结构发育程度及其形态特征,而且当河床结构发育程度较低时,凹凸度的表征结果更具有区分度。结果表明:新参数表征结果与前人单一参数的计算结果具有一致性;吊嘎河下游、陶家小河和清水沟的河床结构凹凸程度大,河床凸起"高凸",凹陷"深陡",河床阻力大,输沙率低;吊嘎河上游、小江、蒋家沟和蓝泥坪沟的河床结构凹凸程度小,河床凸起"低平",凹陷"浅缓",河床阻力小,输沙率大。Riverbed structure in mountainous rivers is the product of the interplay between flow-sediment and riverbed, which determines the magnitude of riverbed resistance and significantly affects the bedload transport. In order to characterize the details of riverbed structure, this study proposed four new dimensionless parameters (concavity-convexity number, average concavity, average concavity, and concavity-convexity) of riverbed structure characterization and their calculation methods based on the topographic survey datasets of seven sections of the main stream and tributaries of Xiaojiang River (a tributary of Jinsha River in the upper Yangtze River) in April and September 2017. The calculation method of four new parameters is simple and intuitive. Four parameters represent the development degree of the riverbed structure and morphological characteristics of riverbed structure. Moreover, the characterization of the concavity and convexity is more distinguishable if the degree of the riverbed development is relatively lower. The results based on the application of the new method show that the bulge of the riverbed structure in the lower reaches of the Diaoga River, Taojia Creek, and Qingshui Creek is relatively high and convex, i. e., the deep and steep depression, high resistance of river bed, and low sediment transport rate. However, the upper reaches of the Diaoga River, Xiaojiang River, and Jiangjia Creek, and Lanniping Creek, the bulge of the riverbed structure is relatively low and flat, i. e., the shallow and gentle depression, low resistance of river bed, and high sediment transport rate.

关 键 词：山区河流 河床结构 形态表征 凹凸度 阶梯-深潭系统 小江流域 

分 类 号：TV147[水利工程—水力学及河流动力学]