1. Introduction
Coastal erosion has recently been a problem that has caught the
public’s attention in Thailand. Erosion has damaged infrastructure
and threatened the livelihoods of coastal communities, especially
along the southern coast of Thailand. An erosion rate of more than
5 m/year has been reported in Nakhon Si Thammarat province
(Saengsupavanich et al., 2009). A number of government agencies,
both local and national, have attempted to mitigate the erosion. The
Marine Department, under the Navigation in Thai Waters Act, is
legally responsible to construct breakwaters, where appropriate, to
defend the coastline.
Detached breakwaters have been successfully implemented to
mitigate coastal erosion (Bowman and Pranzini, 2003; Lamberti
et al., 2005; Saengsupavanich et al., 2009; Sane et al., 2007).
However, the detached breakwaters generally create coastal
morphological changes (erosion/accretion) at adjacent beaches
(Iskander et al., 2007; Thomalla and Vincent, 2003; U.S. Army Corps
of Engineers, 2008). They seem to postpone the erosion unless the last detached breakwater is located at an appropriate spot.