SHORELINE ROTATION CAUSED BY LARGE-SCALE EXCAVATION OF REEF FLAT ON SANUR BEACH IN BALI

Masatoshi Endo, Akio Kobayashi, Takaaki Uda, Yasuhito Noshi, Susumu Onaka

Abstract


In the southern part of Sanur Beach in Bali, beach erosion has occurred between groins after extensive beach nourishment, resulting in shoreline rotation between the groins. The cause of shoreline changes was investigated by field observations, including a bathymetric survey and the sampling of seabed materials, and numerical simulations of beach changes were carried out using Noshi et al.’s model. It was concluded that the shoreline rotation was triggered by the dredging of the reef flat, which caused a change in the wave direction on the reef flat due to the diffraction of waves.

Keywords


coral reef; Bali; Sanur Beach; excavation of reef flat; shoreline change

References


Isobe, M. 1987. A parabolic equation model for transformation of irregular waves due to refraction, diffraction and breaking, Coastal Eng. Japan, Vol. 30, No. 1, 33-47.

Noshi, Y., A. Kobayashi and T. Uda. 2009. Model for predicting bathymetric and grain size changes considering equilibrium beach slopes corresponding to composition of grain size and each grain size, J. Coastal Res., SI 56, Portugal, 108-112.

Onaka, S., S. Endo, T. Uda and I. Yoshii. 2005. Design of beach nourishment and beach response after nourishment on a reef coast, Annual Jour. Civil Eng. in the Ocean, Vol. 21, 475-480. (in Japanese)http://dx.doi.org/10.2208/prooe.21.475

Osuga, Y., T. Uda, S. Onaka, S. Endo, M. Serizawa and T. San-nami. 2004. Rapid formation of a barrier island and beach erosion caused by large-scale excavation of reef flat on carbonate beach, Proc. 29 th ICCE, 2074-2086.

Ozasa, H. and A. H. Brampton. 1980. Model for predicting the shoreline evolution of beaches backed by seawalls, Coastal Eng., Vol. 4, 47-64. http://dx.doi.org/10.1016/0378-3839(80)90005-8

Seino, S., T. Uda, S. Onaka, M. Serizawa and T. San-nami. 2006. Large-scale excavation and land reclamation on reef flat and coral mining on Turtle Island in Bali, Indonesia, Proc. 10 th Inter. Coral Reef Symp., 876-881.

Serizawa, M., T. Uda, T. San-nami, K. Furuike and T. Kumada. 2003. Improvement of contour line change model in terms of stabilization mechanism of longitudinal profile, Coastal Sediments '03, 1-15.


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