NUMERICAL CALCULATION OF BED DEFORMATION IN BRAIDED STREAM WITH EMERGED MID-CHANNEL BARS

Abstract

Development of emerged mid-channel bar is very important in the formation of braided stream. Numerical model is one of the powerful tools to predict the flow and bed topography in braided streams, however, it is very difficult to simulate the flow and sediment transport at the boundary of emerged bars. In this paper, a numerical model is tested under the condition of emerged bars are developed, in which a technique is tested to take into account for the emerged bars. The calculated results are favorably compared with experiments of the formation of braided streams. The formation of braided stream and transformation of bar mode is discussed using the results of the calculation.