This fall’s flooding in Thailand killed more than 700 people while costing 54 billion dollars in damage and lost revenue.
Flooding in Thailand, Oct. 2011
Scientists and weather forecasters are worried about the fate of the capital city, Bangkok. It’s built on a delta of the river Chao Phraya, and has canals as well as roads (flood map).
* Weather patterns are changing and rainfall patterns are becoming more erratic.Typhoons may appear in unexpected places.
* Typhoons have increased from one every 7 or 8 years to one every 3 or 4 years
* The temperature in Thailand has risen two degrees in the last forty years. Consequently, storms have more energy and are more intense.
* Precipitation during the monsoon has risen by 15%. During the rainy season, a metre of rain can fall in less than an hour.
In addition, the city will end up under water:
* The sea level is rising 3 mm per year.
*The city is based on a river delta. Bangkok is sinking into its soft clay substrate about 4 cm a year as water is pumped out.
* In a really big storm, as much as 30 square km will be flooded with overflow from the river and polluted water from the canals.
Bangkok's flood embankments
The King, a hydrological engineer, has made flood control a priority for thirty years. The city is protected from flooding by overflow ponds and channels that take water from upriver directly to the sea. Pumps can lower the level of the canals 20 cm, helping the city to drain. But it’s not enough to control the damage from typhoons and rising sea levels. But there’s no magic in mega0projects. People are leaving their homes near the canals. They remember the great flood of 2538 (1995 in our calendar). They’re piling up sandbags and building barriers and raising their houses.
Coastal erosion is fierce and soil is constantly being washed away in the southern part of the city. One temple has been surrounded by water in the last twenty years and the lower levels are flooded. The village it served has been washed away in the last fifteen years. Only the telephone poles remain.
New York City is another city that is vulnerable to rising sea levels.