Journal of Natural Disaster Science

PREDICTION OF BEACH EROSION AT MUROZUMI BEACH

Yoshito TSUCHIYA
Professor, Disaster Prevention Research Institute, Kyoto University, Kyoto
Masataka YAMAGUCHI
Associate Professor, Department of Ocean Engineering, Ehime University
Yoshiaki KAWATA
Associate Professor
Teruo SHIBANO
Instructor
and
Takao YAMASHITA
Instructor, Disaster Prevention Research Institute, Kyoto University, Kyoto

(Received 30 August, 1980, and in revised form 15 November, 1980)

Abstract

Reclamation results generally in beach erosion of a neighbouring coast. Historical changes of shoreline at Murozumi beach, a pocket beach, are first described in accordance with the reclamation. Main causes of beach erosion are then considered by the characteristics of incoming waves over a period of 10 years and of sediment sampled on the present beach plus the consequential effect of reclamation. A method of prediction is proposed for the long-term change and variation of shoreline by the continuity equation of beach change. The long-term beach change of shoreline so estimated agrees well with the results of field survey. It may be concluded, from comparing the results of numerical simulations of beach changes measured before and after reclamation, that the more advances of beach erosion at the coast, the more severe changes of bottom topography and shoreline can be expected.

Key words

Murozumi beach, beach erosion, reclamation, pocket beach, shoreline changes