Flow resistance in the channel-bar landscape of large alluvial rivers  

作　　者：Yong HU Congcong LIU Jinyun DENG Wei ZHANG Yitian LI 

机构地区：[1]State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China [2]CCCC Second Harbor Engineering Company Ltd,Wuhan 430040,China [3]Key Laboratory of Large-span Bridge Construction Technology,Wuhan 430040,China [4]Research and Development Center of Transport Industry of Intelligent Manufacturing Technologies of Transport Infrastructure,Wuhan 430040,China [5]CCCC Highway Bridge National Engineering Research Centre Co.Ltd,Wuhan 430040,China

出　　处：《Frontiers of Earth Science》2024年第2期412-421,共10页地球科学前沿（英文版）

摘　　要：Accurate approaches for estimating flow resistance in large alluvial rivers are fundamental for simulating discharge,sediment transport,and flood routing.However,methods for estimating riverbed resistance and additional resistance in the channel-bar landscapes remain poorly investigated.In this study,we used in situ river bathymetry,sediment,and hydraulic data from the Shashi Reach in the Yangtze River to develop a semi-empirical approach for calculating flow resistance.Our method quantitatively separates flow resistance into riverbed resistance and additional resistance and shows high accuracy in terms of deviation ratio(~20%),root-mean-square error(~0.008),and geometric standard deviation(~3).Additional resistance plays a dominant role under low-flow conditions but a secondary role under high flows,primarily due to the reduction in momentum exchange in channel-bar regions as discharge increases.Riverbed resistance first decreases and then increases,which might be attributed to bedform changes in the lower and transitional flow regimes as flow velocity increases.Overall,our findings further the understanding of dynamic changes in flow resistance in the channel-bar landscapes of large river systems and have important implications for riverine ecology and flood management.

关 键 词：flow resistance channel-bar landscape interaction region large river BEDFORM 

分 类 号：X826[环境科学与工程—环境工程]