水科学进展2026，Vol.37Issue(3)：540-551,12.DOI:10.14042/j.cnki.32.1309.2026.03.012
三峡水库蓄水后长江中游断面形态调整模式
Adjustment patterns of cross-sectional morphology in the middle reaches of the Yangtze River after the impoundment of the Three Gorges Reservoir
摘要
Abstract
The construction of large reservoirs warrants adjustments to the channel morphology downstream of the dam.Existing studies provide a relatively systematic understanding of the overall characteristics of channel adjustment but lack quantitative criteria for distinguishing the adjustment patterns of different cross-sections downstream of the dam.This study investigates the morphological adjustment patterns to the cross-sections of the Middle Yangtze River following the impoundment of the Three Gorges Reservoir and establishes identification criteria based on fixed-section topographic data.Analysis is conducted from the perspective of the cross-sectional centroid.The main conclusions are as follows:① In the temporal dimension,the longitudinal coordinates(Hy)of the cross-sectional centroid generally decreased.The transverse coordinates(Hx)of the centroid in straight river types varied slightly,whereas those in meandering river types shifted toward the convex bank.Meanwhile,in bifurcated river types,Hx shifted toward the main channel.In the spatial dimension,the greatest adjustment to the cross-sectional morphology in straight-river types occurred in the lower reaches of the Lower Jingjiang reach and the Jiepai reach.Hy decreased the least in the gravel-sand river section near the dam,whereas Hy.changed the most significantly in the Upper Jingjiang reach.For both meandering and bifurcated river types,the greatest relative change in centroid coordinates occurred in the Jingjiang reach and gradually decreased with increasing distance from the dam.② Based on the intrinsic relationship between shape center migration and the oscillation of the hydrodynamic axis,it has been clarified from a dynamic perspective that changes in the shape center can reflect the characteristics of cross-sectional adjustment.③ By introducing the relative amplitude of the centroid coordinates,three cross-sectional adjustment patterns—global downward-cutting,translational downward-cutting,and translational adjustment—along with their identification criteria are proposed.Straight-river types primarily exhibit global downward-cutting,meandering-river types display all three patterns,and bifurcated-river types primarily exhibit global downward-cutting and translational downward-cutting.Compared with previous approaches,this method quantitatively distinguishes differences among river types and demonstrates that the relative amplitude of the centroid can capture the coupled variation between lateral cross-sectional displacement and vertical scouring-deposition processes.关键词
断面形态调整/水沙变化/形心/长江中游/三峡水库Key words
cross-sectional morphology adjustment/hydro-sediment variation/centroid/middle reaches of the Yangtze River/Three Gorges Reservoir分类
建筑与水利引用本文复制引用
章广越,张为,张德毅,陈立,贾朝辉..三峡水库蓄水后长江中游断面形态调整模式[J].水科学进展,2026,37(3):540-551,12.基金项目
国家自然科学基金项目(U2340217) The study is financially supported by the National Natural Science Foundation of China(No.U2340217). （U2340217）
