Coastline change due to storm surge during 1989–2006 at Amphoe Hua Hin, Changwat Prachuap Khiri Khan, Southern Thailand

Abstract

Amphoe Hua Hin, Prachuab Kiri Khan province, which is a well-established beach destination and increasing in popularity among international travelers, is affected problems on shoreline erosion.

The short-term erosion is concentrated in this study; therefore, Typhoon Gay and Typhoon Linda, which are two of the severe storms passing the Gulf of Thailand and hit the southern coastal provinces in 1989 and 1997 respectively, There are the cases of tropical cyclones passing through Thailand and the strong northeast monsoon in December 2006. The strong wind generate high wave. This is cause of storm surge. The influence of wind wave is aim to coastline change on southern coastline. The risky area of erosion has been reported to have the land lost 1 to 5 m/y at Hua Hin area.

In this paper, remote sensing is applied for measure the change areas on coastline of Amphoe Hua Hin, Prachuab Kiri Khan province during typhoon Gay(1989), typhoon Linda (1997) moved over the Gulf of Thailand, and during the strong seasonal monsoon(2006) including with analyze meteorological data to determine wind direction and wave height during these event .The study result revealed that there were eroded of coastline of Amphoe Hua Hin, Prachuab Kiri Khan province during typhoon Gay is 25.39 meters, Typhoon Linda is 10.36 meters and the strong seasonal monsoon on 20-24 December is 1.23 meters. Root mean square error of these results was less than 0.15. In these events, the highest erosion was found between Hua Hin airport and pier of Hua Hin. Moreover, long-term measurement during 1989-2006 showed that there were erosion areas about 16.63 meters, so there was accretion of beach appeared after Typhoon Gay and Typhoon Linda passed. It contradicts the previous research. This result can be used to support coastal study and management in the future.

The case of typhoon passes to the Gulf of Thailand is not often, it generates during ten years. Nevertheless, the strong northeast monsoon can be generated 1-2 times per year. Therefore, shoreline protection should be considered with long term protection to protect the coastline.