Shoreline change after the 26 December 2004 tsunami between Laem Pakarang-Khao Lak area, Changwat Phang-Nga, Thailand

Abstract

The 26 December 2004 tsunami had left an extremely damage to the Andaman Sea coast of Thailand. Lame Pakarang-Khaolak, Phangnga province was the most affected area in shoreline changed from this event. Numerous sediments from shoreface through beach area were eroded suddenly and moved inland rapidly due to the high energy of tsunami wave. Shoreline position was changed inland and inlet/outlet channels were wider. This study aims to monitor recovering process in beach area after shoreline was changed by this event. Remote sensing data and field survey were mainly used in this study. Twelve periods from 2002 to 2006 of satellite images were used to calculate beach area and shoreline change. Field survey was carried out every 3 months for beach profiling and sediment sampling in four periods since January to November 2006. Beach profiles showed the balance of deposition and erosion which the change depends on season changes. Grain size of beach sediments at Ban Gang Niang was coarse to very coarse sand and finer to the north as fine to medium sand at Blue Village Pakarang Resort. Beach sediments were composed of quartz (60%), bio clasts (35%), and others (5%). In conclusion, according to the satellite images analysis and field survey, shoreline and beach areas in the study area were almost recovered after one year whereas inlet/outlet channels (except Ban Bang Niang) were not recovered. In general, eroded areas by 2004 tsunami were approximately 90 percent recovered until November 2006.