MORPHOLOGICAL CHANGE IN TIDAL FLAT AREA DURING HIGH AND LOW WAVE CONDITION USING XBEACH SIMULATION

Abstract

 The Higashi-hazu tidal flat, located in the northern part of Mikawa Bay in Aichi prefecture, has a rich natural environment where a variety of organisms exist. However, it has been experiencing morphological change in a short period due to extreme weather. Therefore, further investigation and monitoring are needed in order to make a proper coastal management and mitigation project. This study investigated the morphological change during 2 different sea conditions (high and low wave conditions) using a 2D numerical model, XBeach. The numerical simulation reproduced the erosion and deposition trend that matches the observation result. This study also discussed the comparison of the morphological responses between storm and calm wave conditions and their influence on sediment transport. During high wave conditions, significant erosion occurred on the eastern side of the tidal flat, with sand being transported mainly westward, leading to deposition in that region. In contrast, during low wave conditions, while some sediment movement was observed, the sand largely remained within the tidal flat area, resulting in minimal morphological change.