Abstract
In the Sangchan beach, coastal erosion had occurred due to human's development till ten years ago. However, since many countermeasures (Y-type groins and detached breakwaters) were constructed, although this coastal erosion came to an end, the recovery of the beach is insufficient. Therefore, in this paper, the safety at the Sangchan beach by existing countermeasures is confirmed and some improvement plans for raising the safety to coastal disaster are examined. The models of Ca et al. and Yamamoto et al. are used to evaluate the difference of coastal erosion between those plans to the present condition, and the equations of Van der Meer et al. and Yamamoto & Horikawa's are used to evaluate the difference of wave overtopping rates between those. As conclusion, the comprehensive comparison of examination results makes it clear that sand nourishment is the most proper countermeasure.
