FIELD OBSERVATION OF MOVEMENT OF SAND BODY DUE TO WAVES AND VERIFICATION OF ITS MECHANISM BY NUMERICAL MODEL

Takaaki Uda, Yoshimichi Yamamoto, Naoki Itabashi, Kosuke Yamaji

Abstract


Bottom sounding data collected from 1983 to 1993 on the Shizuoka coast were analyzed. The results reveal the existence of a sand body moving downcoast at a velocity of about 233m/yr. It is the first time that this kind of phenomenon was observed in the quantitative sense including the spatial and temporal changes in longitudinal profile of the beaches, and this propagation mode is a very interesting phenomenon. In this study, sand movement shoreward and offshoreward of the detached breakwaters is modeled, and a model to predict successive contour line changes is developed, taking into account of time lag caused by the obstruction effect of longshore sand transport due to the detached breakwater. The new phenomenon observed on the Shizuoka coast is well explained by the present model. The propagation velocity of the sand body reproduced by this model is 230m/yr and it is well in agreement with the field observation value.

Keywords


numerical model; field observation; sand body; model verification

Full Text: PDF

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.