RESEARCH ON THE ESTIMATION METHOD OF COASTAL PROTECTION STRUCTURES HEIGHT ON THE COAST OF JAPAN

Abstract

 Coastal flood area is usually evaluated using a digital elevation model, but it is considered that the results are overestimated because the digital elevation model does not include the information of coastal protection structures height. Construction of coastal protection structures is progressed based on the construction standard; however it is not completed countrywide. This study focused on the estimation of the height of coastal protection structures in Japan based on the assumption that the coastal protection structures are constructed at least the level up to the usual height of sea surface caused by tide, waves and storm surge. The estimated results was verified by the coastal protection structures height measured in field investigation conducted in this study. The results showed a good agreement with the measured height at the coast where external forces are assumed to affect to the water surface height. However, on the coast affected by tsunami, the results showed large differences between the estimated and measured heights, and the estimated height of tsunamis should be included in the estimation.