HYDRAULIC EXPERIMENT FOR DISTRIBUTION OF SAND DEPOSIT FORMED ON SLOPE BY TSUNAMI

Abstract

 In the present study, a hydraulic experiment with moving bed was carried out in order to investigate the influence of particle size of sand, slope of run-up areas, and tsunami conditions, to distributions of sand deposited on land slopes by tsunamis. Then, the following matters were examined by using experimental data; the relationship between the run-up distance and deposit formation distance, the relationship of the distribution of the sediment and the incident wave, the difference in the distribution of the deposit due to the difference in particle size of the source sand, the distribution of the deposit by uniform sand and mixed sand. From experiment results, it is shown that the ratio of deposit formation distance and tsunami run-up distance is influenced 0.67 to 1.0 by particle size of sand. This ratio is also changed by slope condition and tsunami wave settings. And the mass distribution of deposit is changed by the particle size of source sand. When utilizing tsunami deposits, it is necessary to consider not only layer thickness but also particle size.