Typhoon LINDA crossed the Gulf of Thailand on 4 November 1997 which it caused the loss of lives and damage to property as it proceeded northwestward from the southern tip of Vietnam to near Huahin and further into the Andaman Sea. Consequently the storm surge that was seen along the shoreline north of the standing point was due to the strong onshore wind, piling up the water mass. We used ocean model in order to estimate the maximum surge to be 61 cm due to wind stress. If the tide were included, the maximum surge height would be 90 – 100 cm, calculated somewhere north of Cha-Am in the upper Gulf.

The disaster of Typhoon LINDA caused a serious threat to life and property. During the typhoon passed coastal zone of Thailand. It swept marine plant and animal, coastal erosion etc.

Storm surge is the most dangerous part of a typhoon. When a typhoon goes over land, the storms surge causes serious flooding. Most of the storm surge is caused by wind. The wind in a typhoon is blowing in the same direction. This causes the ocean water to pile up. In the open ocean, the water can flow away under the storm. As the typhoon nears land, the water can't flow under the storm so it builds up, this is most of the storm surge which it push the water into the continental shelf and onto the coastline. The height of a surge is basically measured as a deviation from the mean sea level in the area, and in some historical storms, this value has reached over 20 feet.

In Thailand storm surges have occurred in the coastal areas of the Gulf of Thailand. In 1962 the storm surges accompanying tropical storm HARRIET that affected the Laem Taloom Pook peninsula in southern Thailand, caused severe damage and more than 900 deaths. Typhoon GAY in 1989 also caused storm surge on the east coast north of Chumphon and along the Rayong coast near the head of the Gulf.

As the Typhoon LINDA passed the Gulf of Thailand, strong winds were experienced north of the typhoon track. The center mean sea level pressure was only of the order 5 hPa lower than the undisturbed pressure field. Consequently the storm surge that was seen along the shoreline north of the standing point was due to the strong onshore wind, piling up the water mass. We used ocean model (SEAWATCH 3D) in order to estimate the maximum surge to be 61 cm due to wind stress. If the tide were included, the maximum surge height would be 90 – 100 cm, calculated somewhere north of Cha-Am in the upper Gulf and I have also run WAM model to forecast significant wave height as below.

Storm surges associated with severe tropical cyclones stand out as by far the most damaging among natural disasters. They must be regarded as a serious threat to life and property in our coastal areas. Many disasters are involved in the formation and propagation of a storm surge, such as the strength and size of the storm, bottom conditions where the surge comes ashore, and the position of the storm center relative to the shore. In addition the ecosystem, fishery industry, environment and tourism industry are also impact from storm surge. With high concentration of population near the coasts, demand for quantitative estimates of vulnerability to storm surges of different coastal stretches have increased during recent years.