PREDICTION OF THE MAXIMUM WAVE ON THE CORAL FLAT

Abstract

Beach erosion has become a major problem at coral-sand beaches in Bali, Indonesia, due to the rapid changes in natural environment and utilization of coastal areas. An observation ofwaves was carried out at Sanur beach in Bali to know what waves are effective for beach processes. The representative waves are predicted by use ofthe mild-slope and KdV equations with evaluation of the coefficient of bottom friction. Empirical formulae of wave energy dissipation are proposed for taking into account of wave height damping due to breaking on the coral flat. The maximum wave on the coral flat, occurring in the reforming region ofwaves after breaking near the reef edge, can be decided by the theoretical results of the highest wave of permanent-type on water of uniform depth. Sanur beach has observed swells with a period longer than 15 sec, being incident onto the coral flat without breaking. This maximum wave of non-breaking progressive-type is, therefore, evaluated by the experimental wave height criteria.