长江科学院院报2024，Vol.41Issue(6)：18-27,10.DOI:10.11988/ckyyb.20230339
长江中游武汉河段江心洲的差异化冲刷规律
Differential Scour of Two Mid-channel Bars in Wuhan Reach of the Middle Yangtze River
摘要
Abstract
Over the past two decades,mid-channel bars in the branching sections of the Middle Yangtze River have experienced substantial scouring or even retreating,yet the specific variances in scouring between slightly meander-ing and straight channels remain unclear.Baishazhou Sandbar and Tianxingzhou Sandbar,located in the Wuhan reach of the Middle Yangtze River,were selected as study sites to investigate the causes of morphological changes and differential scouring.This investigation utilized a combination of multi-source remote sensing imagery,hydrolog-ical data,and field surveys.The findings reveal significant alterations in the morphology of Baishazhou Sandbar,shrinking in size by approximately 43.83％between 1989 and 2020.Meanwhile,the head of Tianxingzhou sandbar underwent notable changes,although the overall exposed area remained relatively stable.Analysis of the normalized vegetation index(NDVI)indicates generally low vegetation cover on both sandbars,with diminished spatial dis-crepancies.During dry season,variations in exposed area primarily correlate with the bar head region.Specifically,on the Baishazhou Sandbar which is located in straight channel,scouring was observed on the head and lateral side,while local collapse on the left side,both due to the obstruction of Baishazhou Bridge piers.Similarly,on Tianxingzhou Sandbar which is located in slightly meandering channel,the bar head has experienced scouring fol-lowing the impoundment of the Three Gorges Project.However,the implementation of protection measures,inclu-ding artificial rock rip-rap in 2004,effectively mitigated scouring and facilitated deposition.In conclusion,differen-tial scour of mid-channel bars manifests in several aspects,including channel planform,the relative positioning of mainstream and branches,and the presence or absence of protective infrastructure.关键词
江心洲/微弯河段/顺直河段/差异化冲刷/水沙变化/长江中游/武汉河段Key words
mid-channel bar/slightly meandering reach/straight reach/differential scour/water-sediment change/Middle Yangtze River/Wuhan Reach分类
建筑与水利引用本文复制引用
王茜雅,李志威,马嘉怿,白宽宽..长江中游武汉河段江心洲的差异化冲刷规律[J].长江科学院院报,2024,41(6):18-27,10.基金项目
国家重点研发计划项目(2023YFC3209502) （2023YFC3209502）
湖北省技术创新重点研发计划项目(2023BCB110) （2023BCB110）
