Recent Evolution Trend and Mechanism of Hechangzhou Braided Channel in Zhenyang Reach of Yangtze River

摘要

The Hechangzhou Braided Channel in Zhenyangrn(Zhenjiang-Yangzhou) Reach is one of the severely changingrnsections in the lower reaches of Yangtze River. To effectivelyrnforecast the evolution trend of this reach and prevent disaster, thisrnpaper is mainly based on the concepts and methods of GIS. Usingrnthe noted geographic information software MapInfo 9.5 and Surferrn8.0, we digitized the scanned river survey maps (1:10000) ofrnHechangzhou in 1974, 1978, 1997, respectively, and establishedrnthe Digital Elevation Model (DEM) for this river section. Then thernrecent plane deformation, water depth variation and scour-and-fillrnfeature of Hechangzhou Braided Channel were analyzed. Thernevolution mechanism was also concerned through the points ofrnincoming water & sediment conditions and geologic-geomorphicrnfeature of Hechangzhou Channel. Finally, some suggestions werernprovided for the third phase project in Zhenyang Reach andrnfollowing regulations.