Daisaku Sato, Hiromune Yokoki


Numerical simulations of coral gravel transportation were conducted to estimate the accumulation possibility in the gap which is formed by the open-cutting of the causeway in Fongafale Islet of Funafuti Atoll. In the numerical simulation of wave field, the high wave conditions were considered in the boundary condition. Calculated morphological change in the gap showed that the extremely large accumulation of coral gravels was not estimated. However the southern edge of the gap had large accumulation locally. In the middle and northern part of the gap accumulated gravel formed thin layer. Because the calculated morphological change of lower wave condition showed large accumulation as well as the results of higher wave condition, it is estimated that the direction of incident wave is important factor of the accumulation. The simulated result indicated that the rapid blockade of the gap would not be caused by accumulation of coral gravels. However, the periodic maintenance of the gap is required for keeping the function of the gap continuously.


coral gravel transportation; numerical simulation; Funafuti atoll

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