experimental investigation of bed evolution resulting from dam break

This study examines the relations between structures and shapes of streambed evolution after dam-break floods. a flume was used to simulate dam-break floods with variations of initial upstream water levels and variance, from uniform to graded, of bed sediments. detailed measurements of the state and composition were made during these experiments. the data indicate that intense scour occurred immediately downstream of the “dam break” location in both uniform and graded sediments. the resulting bed surfaces of graded sediments showed coarse-fine- coarse structures in the areas with the lowest scour and highest deposition and various types of clusters (i.e., line and heap). this pattern was not observed in uniform-sediment beds. the scour holes changed from circular to oval-shaped in both uniform and graded sediments as bed slopes increased.