Morphological Change in Shichiri-Mihama Ida Beach

Abstract

This manuscript demonstrated the characteristics of morphological change in Shichiri-mihama Ida coast, located in the southern part of Mie prefecture, by means of discriminant analysis based on shoreline change characteristics analyzed by network camera and wave data, and SfM/MVS analysis using UAV. Additionally, the correlation between the run-up height and the morphological change was discussed. As a result, discriminant analysis showed the usefulness of estimating advance, retrogression and stay events of shoreline behind artificial reefs at Ida beach. In the results of SfM/MVS analysis, the effectiveness of artificial reefs installed in Ida beach to reduce erosion behind artificial reefs, while it was confirmed that the function of artificial reefs to decline erosion was decreased by the long period waves with a significant wave period more than 13s. The total volume of Ida coast has increased due to the recently implemented beach nourishment. However, because the large beach nourishment material makes the foreshore slope of the Ida coast steep which is possible to accelerate beach erosion, the necessity of ongoing monitoring was suggested. Finally, the possibility to predict the maximum altitude of morphological change in Ida coast foreshores from the calculation of the run-up height by considering the wave direction of the wave after passing through the artificial reef was confirmed.