洪水流による砂州の移動・変形と砂州粒度構成の変化

抄録

The movement and development of the local scour is associated with the sandbar movement and transformation. The local scour around the river structure increases the risk of the structure failures. Therefore it is important for structures maintenance and management to clarify the characteristics and grain compositions of the sandbar. So, we surveyed the grain composition of sandbar in the Tama River in 2008. And we show the movement and transformation of the sandbar during the 2007 flood, which is the largest Tama River flood in recent years, using the digital map data and the cross section survey data. Then, the characteristics of sandbar movement and transformation and grain size composition of the sandbar are discussed. And we develop numerical model for bed and grain composition variation during the 2007 flood by the quasi-3D flow and bed variation model with segment mixture.