Detached breakwaters: communities' preferences for sustainable coastal protection

Detached breakwaters have been implemented for coastal protection. As society evolves and community livelihood has been acknowledged as an ingredient for sustainable coastal development, the breakwaters must do more than just dissipate wave forces. Using detached breakwaters in Nakhon Si Thammarat province, Thailand as a case study, this research provides empirical proof of such a concept. Interviewing coastal communities who have lived with the breakwaters revealed numerous expectations. Since each community's requirement might be entangled with other functions and incur more costs, coastal engineers had to prioritize preferences. Seven breakwater scenarios were synthesized based on the interview results. For each scenario, the shoreline position was simulated using calibrated LITPACK software, the construction cost was estimated, and a set of illustrations was drawn in order to standardize respondents' perceptions. An analytical hierarchical process (AHP) was applied. The AHP results suggested that the preferred breakwater scenarios were those that promoted the existing ways of life. Other aspects such as construction practice, environmental, and social aspects should also be thoroughly considered.