QUANTIFICATION OF LEVEE BREACH VOLUME BASED ON LEVEE BREACH AT THE CHIYODA EXPERIMENTAL FLUME

Abstract

 In recent years, disasters caused by typhoons, localized downpours, and other phenomena have occurred frequently, and concern over the risk of large-scale water damage caused by river flooding has risen. Although damage resulting from levee breach is particularly serious, there is a lack of technical data on the mechanism behind that phenomenon. Accordingly, this mechanism needs to be clarified to reduce the risk of flood damage.
 We examined the relationship between the quantification of the levee breach volume and hydraulic parameters. In the widening stage of levee breach, the breach phenomenon can be described in terms of the traction of soil masses from the levee body as a result of flood flow. It was also found that the relationship between the extent of dimensionless levee collapse and dimensionless traction force around the mouth of the breach can be expressed in a form similar to that of the bed load formula.