Author(s): Watin Thanathanphon; Narongrit Luangdilok; Kachapond Chettanawanit; Piyamarn Sisomphon
Linked Author(s):
Keywords: Gulf of Thailand; Tropical Storm Pabuk; Early warning system; Storm surge; Inundation
Abstract: Tropical Storm Pabuk was the latest severe storm in the past two decades since Typhoon Linda in 1997 that had its landfall in the southern region of Thailand. It brought heavy rain, strong wind and high level of surge that caused widespread of coastal flooding especially in the low-lying area. This event had been monitored since the storm was formed in the South China Sea. Its formation and track were closely monitored and predicted for the strength, track and impacted area. The storm surge forecasting and early warning system for the Gulf of Thailand was developed using Delft-FEWS as operational platform. Delft3D-FM and SWAN models were used to compute the total water level that combined effect of tide, wave and surge. Finally, Tropical Storm Pabuk had hit the land at Pak Phanang, Nakhon Si Thammarat on 4 January 2019 afternoon with wind speed reaching 83 km/hr. It was found that the model could capture the whole phenomena satisfactory. The total water level, flow direction, time of landfall and impacted area were computed with good accuracy. The comparison between computed and observed water level from the water level stations showed strong correlation and good agreement. The inundation area was also estimated using wetting and drying scheme in Delft3D-FLOW. SRTM 90m was used for the land topography to simulate coastal flooding during the storm. The estimated inundation area using the model has been compared with observed flood map from RADARSAT-2 satellite. The results showed a good agreement especially in the low-lying area including estuary, mangrove and local community area.
Year: 2020