Abstract
A simple parametric model was developed for the systematic migration of sandbars on the Chirihama and Takamatsu Coast, Ishikawa, Japan. First, the principal modes of morphological variation was extracted by an EOF analysis for the annual surveys over 11 years. The cyclic migrations were well reproduced by the combination of the first and second eigen-modes, and the corresponding eigen-functions were examined in detail. The temporal eigen-functions for these modes were approximated by a sine and cosine function, respectively. The variations in phase and amplitude associated with the temporal eigen-functions were then expressed by linear regressions. The variations in phase and amplitude of spatial eigen-functions were approximated by exponential curves and the combination of linear and parabolic curves. The final expression was constructed by the combination of the approximated temporal and spatial eigen-functions. The approximated variations well reproduced the transition of the multiple sandbar systems.
