Bangkok: Sinking city

Nine homeowners in suburban Bangkok were forced to flee earlier this week as their homes literally sank and fell apart in the wet earth where they were built.

The trying moments of the nine families in Pathum Thani province, just above Bangkok's second international airport, Don Mueang, put the accent on the fact that Bangkok is slowly sinking back into the swampland where it was constructed in the 18th century.

The city, just 235 years old, is currently sinking at an average rate of about two inches per year, according to geologists and scientists.

Sometimes the subsidence is shown dramatically. In the Pathum Thani tragedy, nine two-storey houses in a local subdivision began sinking at an alarming rate. Men, women and children scrambled out into already muddy yards. The houses had half disappeared and were breaking up, within 12 hours.

Experts from the Engineering Institute of Thailand (EIT) arrived quickly to examine the situation. Their boss, Thanet Weerasiri, said a combination of factors had caused the sudden breakdown.

The houses, of course, were not constructed properly, First, the lot on which they were built was filled with soft soil to depths of 20 to 50 yards. Then the building, incompetent or careless, failed to fix proper piling for the soft soil. When the rains came, the houses went.

It was, however, simply a dramatic illustration of the problem that Bangkok faces. The more people, and the more pumping of groundwater, the more the city sinks.

The center of the sprawling Thai capital has subways and numerous skyscrapers of 40 floors and more, with more being built all the time. Many have excellent piling, and the subway - constructed by horizontal boring - is rated among the world's safest.

Overall, though, the city continues to sink, and there are no plans or programs in place to deal with this.

Every year, Bangkok flooding gets worse, as it takes more time the drain off the water in a city that in many places is actually below sealevel.