水利学报2025，Vol.56Issue(5)：587-598,12.DOI:10.13243/j.cnki.slxb.20240612
三峡建库后荆江洲滩变形及其与水文情势变化对植被的叠加影响
Evolution of channel bars in the Jingjiang River reach after the impoundment of the Three Gorges Reservoir and its combined effects with hydrological regime on vegetation
摘要
Abstract
After the impoundment of the Three Gorges Reservoir,it has become a consensus that the increased dura-tion of low and medium flows in the Jingjiang River reach,combined with sub-saturated sediment-containing flows,has caused sustained scouring of the main channel.However,a unified understanding of the evolution characteristics of channel bars above the basic channel has yet to be established.This study focuses on the Jingjiang River reach and analyzes changes in channel bar areas within different discharge based on observational data collected after the impoundment of the Three Gorges Reservoir.Based on morphological change method and remote sensing analysis,variations in channel bar areas across different sections and time periods were examined.The deformation characteris-tics of channel bars at different elevations were analyzed at both river reach and local scales,and the adjustments in suitable vegetation zones resulting from changes in channel bar evolution and hydrological conditions were assessed.The results indicate that the adjustment of channel bars in the Jingjiang River reach primarily occurred after 2008.In the Zhicheng-Yangjianao section,channel bars exhibited continuous degradation and shrinking,while in the Yangjianao-Jianli section,low and middle bars shrank,and high bars showed slight aggradation.In the Jianli-Chenglingji section,low bars shrank while middle and high bars experienced significant aggradation.Under the over-all trend of low bar erosion,although channel regulation projects can prevent localized erosion and may even promote deposition,their impact on middle and high bars is not significant.In the section influenced by backwater from Dongting Lake,the deposition of channel bars is mainly reflected in the increase in elevation,but the change of the planform is not significant.After the normal operation period of the Three Gorges Reservoir began,changes in chan-nel bar deformation and hydrological conditions together resulted in a 32.0％increase in areas suitable for high-frequency vegetation coverage in the Jingjiang River reach.The increases in the Zhicheng-Yangjianao,Yangjianao-Xinchang,Xinchang-Jianli,and Jianli-Chenglingji sections were-5.6％,6.5％,13.3％,and 95.6％,respectively.There is potential for high bar deposition and an increase in vegetation-covered areas in the lower Jingjiang River,particularly downstream of Jianli,which may increase resistance to flood discharge and should be given due attention.关键词
荆江河段/三峡水库/洲滩冲淤/植被变化Key words
Jingjiang River/Three Gorges Reservoir/channel bars evolution/vegetation changes分类
水利科学引用本文复制引用
李芷晴,陈立,冯恺,孙昭华..三峡建库后荆江洲滩变形及其与水文情势变化对植被的叠加影响[J].水利学报,2025,56(5):587-598,12.基金项目
国家自然科学基金项目(52479074,51879198) （52479074,51879198）
水利部三峡后续研究项目(12630100100020J005) （12630100100020J005）
