Since hydraulic conditions of actual rivers vary over a wide range, phenomenon analysis of experiments with a wide range of hydraulic conditions is indispensable for analyzing levee breach phenomenon. In this study, results of the preliminary experiment conducted for a levee breach experiment using experimental flume were organized and characteristics of levee breach progress were discussed based on the results of the experiment with varied river width and riverbed slope. As a result of the small scale levee breach experiment, it was found out that the levee breach speed was fast and flood volume kept increasing without drawdown of river channel in the cases of wide river width and high-angled riverbed slope. The topographic changes of the small scale levee breach experiments showed the similar tendency with the full-scale experiment. The estimated formula of collapse volume also showed the similar tendency.
