STUDY ON RIVERBED VARIABILITY BY VERTICAL PARTICLE SIZE ANALYSIS OF RIVERBED MATERIALS AND NUMERICAL SIMULATION OF BED DEFORMATION USING OCCUPANCY OF RIVERBED MATERIALS

Abstract

 The flood damage caused by a typhoon and the heavy rain was frequent in Japan. River management became important in such situation. The particle size distribution of the riverbed materials in the river channel was an important index from the viewpoint of sediment management. However, many considerations for particle size were related to the surface layer of the river bed.The examination about the riverbed materials at the deeper point was not carried out. These information was very important parameters to affect the precision of the numerical simulation.

 In this study, the change of the particle size distribution in the horizontal and vertical direction gathered riverbed materials and considered from multiple points at the Babamegawa River. In addition, the numerical computation was performed using a got particle size distribution. Then it was compared the mixed-sized particle with the uniform grain diameter. As a result, a calculation in the mixed-sized particle was the highest in precision. The case of using the peak value of the occupancy rate became highest in precision by the numerical computation of uniform grain diameter.