Tsunami accompanied with the Sumatra earthquake of 26 December 2004 affected many countries around the Indian Ocean. Thailand located approximately 500 km east of its source, was also severely suffered from the tsunami. From 24 February through 4 March 2005, we surveyed the damaged areas in Thailand from south of Phuket Island up to the border of Myanmar including four islands. The whole coastal area facing the Andaman Sea could be covered. We measured 37 points in total, the tsunami heights are less than 10 m, except at a few locations. We found that the largest tsunami height reached up to 19.6 m at Ban Thung Dap of Phra Thong Island. During our survey, we also collected five paper copies of analog tide gauge records. In addition that we could detect two other tide gauge records from the web-site. Therefore, totally seven tide gauge records were obtained in Thailand. All of the recorded tsunami waveforms indicate that sea level initially withdrew with duration in 30 to 60 min, followed by the rising-up. This phenomenon corresponds to the eyewitnesses' accounts of the survivors who experienced the tsunami.

This article presents an investigation of wave fields during the approach of typhoon LINDA in 1997 in the Gulf of Thailand. Two modeling approaches are studied: The hard computing approach by the WAM cycle 4 model was used first to simulate wave heights and periods distribution covering the domain 958E to 1058E and 58N to 158N. Then, the soft computing approach by the GRNN model was developed to predict the wave characteristics for lead times of 3, 6, 9, 12, and 24 h. The input wind data were obtained from NOGAPS model archives with 18 resolution and are linearly interpolated to specify wind components at each grid point. The WAM model underestimated the wave height as much as 20%. The root mean square errors (RMSEs) and the mean absolute deviations (MADs) are 0.18-0.26 m and 0.13-0.18 m, respectively. The GRNN showed better forecasting results than the WAM model (RMSE<0.15 m and MAD<0.10 m). The maximum wave height simulated by the GRNN model during the typhoon Linda 1997 event was found to be 4.0 m. This indicates that for short-term prediction within 24 h, the data-driven model such as the GRNN should be viewed as a strong alternative in operational forecasting.

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This paper presents an investigation of wave field during the attack of typhoon Linda in 1997 in the Gulf of Thailand. Two modeling approaches are studied: The hard computing approach by the WAM cycle 4 model was used firstly to simulate wave heights and periods distribution covering the domain 95°E to 105°E and 5°N to 15°N. Then, the soft computing approach by the GRNN model was developed to predict the wave characteristics for lead times of 3, 6, 9, 12, and 24 hrs. The input wind data were obtained from NOGAPS model archives with 1 degree resolution and are linearly interpolated to specify wind components at each grid points. It was found that the WAM model underestimated the wave height as much as 20%. The root mean square errors (RMSE) and the mean absolute deviations (MAD) are 0.18-0.26 m and 0.13-0.18 m, respectively. The GRNN showed better forecasting results than the WAM model (RMSE < 0.15 m and MAD <0.10 m). The maximum wave height simulated by the GRNN model during the typhoon Linda 1997 event was found to be 4.0 m while the observed data was 4.06 m. This indicates that for short-term prediction within 24 hrs, the data-driven model such as the GRNN should be viewed as a strong alternative in operational forecasting.

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