ABSTRACT
Since Three Gorges Reservoir runs at 175 m as normal level in 2008, the Chongqing reach have been the changeable back water zone. Gravels, rather than fine sediments are the key material which influence the river bed evolution according to more than 10 years field measurement along fluctuating backwater zone. And it very different from former researches. Then the bed load transportation near Chongqing reach is a hot point of researchers because of the influence on the inland navigation security and river bed evolution while Chongqing is the important inland navigation center of upper Yangtze river.
