INVESTIGATION OF THE INFLUENCE OF PADDY RIDGES ON THE SUSPENDED LOAD DEPOSITION DURING INUNDATION

Abstract

 A series of physical experiments was conducted to investigate the influence of paddy ridges on the suspended load deposition under the scenario of embankment failure. A constant flow discharge and sediment was supplied at the breach as the inlet boundary, and three experimental cases were conducted by varying the downstream boundary height with or without using ridges. Experimental results show that, in the case of presence of downstream wall, the deposition occurred mainly in the vicinity of the inlet boundary and along the main flow direction. In the case of the open downstream boundary, no deposition was seen to occur near the inflow boundary owing to the high bed shear stress, most of the sediment was transported downstream and deposited there. In the vicinity of the paddy ridges, sedimentation was found at the back of the ridges but not at the front side and downstream of the ridges. A two-dimensional numerical model used here could generally simulate the deposition area and thickness, but it cannot provide sufficient explanation of the deposition near the ridges due to the three dimensional flow characteristics of the water in this area.