Abstract: Developed in the early 1950s in the Taixing reach of the Yangtze River, Tianxingzhou central island experienced the rapid development stage from 1950s to 1970s, the scouring and silting adjustment stage from early 1980s to late 1990s, and the stable stage since late 1990s. The formation mechanism and the evolution of this central island is studied to provide reference for the harnessing of the river course and the development of the shore line. This study shows that large slow flow area was formed because of the riverbed broadening in the Taixing reach and the ski jump effect of the bank node, thereby resulting in sediment deposition and underwater shoal, which laid foundation for the formation of Tianxingzhou central island. Whereas the large scale collapse of the river bank in the upper Sima bend from the early 1950s to late 1970s provided sufficient sediment for the rapid development of Tianxingzhou central island.

Key words: central bar , formation mechanism, evolution , bank collapse , Tianxingzhou central island