@article{Ishikawa_Uda_Hosokawa_San-nami_2020, title={RECOVERY OF SANDY BEACH AFTER TYPHOON WAVES - CASE STUDY ON CHIGASAKI COAST}, url={https://icce-ojs-tamu.tdl.org/icce/article/view/10352}, DOI={10.9753/icce.v36v.papers.42}, abstractNote={<html>Beach topography quickly changes in response to the action of storm waves, resulting in erosion of the foreshore with accretion under a calm wave condition after a storm. These seasonal beach changes may occur on beaches with protective measures or artificial beaches produced by beach nourishment. On these beaches, the shore protection function of a sandy beach is reduced when a trough is formed immediately offshore of the shoreline and the foreshore slope increases, indicating the importance of the study on topographic changes. Moreover, the time required for a beach recovery in response to wave conditions has not been sufficiently studied, along with the 3-D topographic changes associated with beach cycles. In this study, we aim to investigate these issues using the Narrow Multi-Beam survey data, wave data, and seabed materials data, taking the Chigasaki coast as an example. It was found that a seabed shallower than 2 and 3 m depths was eroded by rapid offshore sand transport during a storm event with the deposition of sand in a zone between 3 and 5 m depths, and then the beach recovered within 1-2 years after the storm. It was also confirmed that a bar and trough disappeared in 1-2 months under the conditions of HE = 0.5 m, TE = 8 s, and H/L = 0.005 when the crown depth of the bar was smaller than approximately 2 m. Thus, the topography after the storm waves recovers within several months or 1-2 years depending on wave conditions and the crown depth of the bar.<br><br><b>Recorded Presentation from the vICCE (YouTube Link): <a href="https://youtu.be/W_P_3p_xd8U">https://youtu.be/W_P_3p_xd8U</a></b></html>}, number={36v}, journal={Coastal Engineering Proceedings}, author={Ishikawa, Toshinori and Uda, Takaaki and Hosokawa, Jun-ichi and San-nami, Toshiro}, year={2020}, month={Dec.}, pages={papers.42} }