泥沙研究2017，Vol.42Issue(2)：21-27,7.DOI:10.16239/j.cnki.0468-155x.2017.02.004
基于TM/OLI影像的河道平面形态演变机理分析——以监利弯曲汊道段为例
Meandering and anabranching channel planform processes and dynamics using remote sensing data——Case of Jianli reach in the middle Yangtze River
摘要
Abstract
The conveyance of water and sediment produce complex channel planform of the meandering and anabranching river pattern dominated by not only second current due to centrifugal force in the flow but also the dynamic characteristics of bifurcation and confluence regions.Nine landsat images acquired in 1987,1990,1994,1996,2000,2003,2006,2010 and 2014 on Jianli reach in the middle Yangtze River were selected.Remote sensing image processing techniques and GIS were applied to interpret and extract the channel planform information.The results show that there are obvious changes in the channel width of two branches from 1987 to 2014,with the width of the left branch reduced from 1041m to 340 m and that of the right branch increased from 632 m to 1531 m.The maximum length of the island increased about 900m and the average width decreased about 200m,with the mean length-width ratio of the island increased from 3.59 to 4.32.During 1994 to 1996,the main branch switches from left channel to right channel.The yearly flow discharge and sedi ment transport rate from 1951 to 2013 were used to explore the mechanism of channel planform evolution.It is found that the switches of the main channel from one to another may be caused by the increase of the flow discharge from 1980s which lead to the flow dynamic axis moving right.In order to maintain an appropriate con veyance of water and sediment,Jianli anabranching planform responds to the change in the matching regimes of flow discharge and sediment transport rate from'high-sediment and low-water'regime to'high-water and lowsediment'by narrowing the island width and increasing the surface width.关键词
遥感/监利河段/平面形态/弯曲分汊/自动调整机理Key words
Remote Sensing/Jianli reach/channel planform/meandering and anabranching river pattern/self-adjusting mechanism分类
建筑与水利引用本文复制引用
刘晓芳,黄河清,余国安,彭昊..基于TM/OLI影像的河道平面形态演变机理分析——以监利弯曲汊道段为例[J].泥沙研究,2017,42(2):21-27,7.基金项目
国家自然科学基金项目(41601006,41330751,51309111) （41601006,41330751,51309111）
黑龙江省应用技术研究与开发计划项目(GZ16B011) （GZ16B011）
