They're the result, at least partially, of not enough field and forest areas to soak up rainfall. Indeed, even droughts are increasing in severity, year by year, and for a similar reason – increasing amounts of fields and forests are being covered up. I propose a one-time tax of Bt100 on each square metre of property that gets covered in future construction projects. This would not only include the footprint of a building, but also its sidewalks, driveways, sheds, parking areas, swimming pools – essentially any soil that gets covered up or compacted too hard to soak up water.
The revenue generated could be put toward reclaiming land that was unwittingly covered up earlier. There are millions of rai throughout Thailand that have been covered up, mostly by cement. Much of those rai are fallow and/or have fallen into disuse. One need look no further than the many deteriorating buildings that were foreclosed upon after the 1997 financial crisis.
Ken Albertsen
Chiang Rai