Author/Authors :
Khosravi, Khabat Department of Civil Engineering - Guilan University, Rasht, Iran , Habib Nejad, Mahmood Department of Watershed Management Engineering - Faculty of Natural Resources - Sari Agricultural Science and Natural Resources University, Sari, Iran , Shahdedi, Kaka Department of Watershed Management Engineering - Faculty of Natural Resources - Sari Agricultural Science and Natural Resources University, Sari, Iran , Chegini, Amir H.N. Department of Civil Engineering - Guilan University, Rasht, Iran , Tiefenbacher, John P. Department of Geography - Texas State University, San Marcos, Texas, USA
Abstract :
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.
Keywords :
Dam break , Experimental , Bed-surface composition , Graded and uniform sediment , Scour
