Abstract
The sand-bar in the Kawasaka district of the Kita River was excavated with vegetation in 2001 through the special emergency project after the sever disaster due to flooding by Typhoon No.19 in 1997. A flood on Oct. 2004 destroyed again almost all vegetation in a recovery process on the sand-bar. Nowadays, herbaceous vegetation is restored over all the sand-bar because of no flooding since 2008. In the paper, the destruction of herbaceous vegetation by the topographical changes of sand-bar was described from field survey and simulated through the 2-D analysis of the riverbed evolution. It was considered from the field survey that almost all vegetation were lean in 1/3 the height. Moreover, destruction of herbaceous vegetation has been reproduced by the built model.
