24 October 2010

Landslides from typhoon Megi in Taiwan

Posted by Dave Petley

The passage of typhoons past or across Taiwan often leads to the generation of exceptionally high rainfall totals that, when combined the steep topography and weak rocks, inevitably triggers extensive landsliding.  The late season typhoon Megi, whose erratic course meant that it somewhat unexpectedly brought heavy rainfall to Taiwan at the end of last week, was no exception:

Over a 48 hour period the typhoon brought over 1200 mm of rainfall to parts of NE Taiwan.  This area is home to one of the world’s most spectacular coastal roads – the so-called Suhua Highway, which runs along the east coast from a Su-ao in the north to Hualien in the central east of Taiwan:

This road  is popular with tourists both because it is a logical route back to Taipei for a round island tour and because the scenery is spectacular (image from here):

Unfortunately however, this is a very dangerous stretch of road in the heavy heavy rainfall associated with typhoons.  During Megi, this is the area that received the most intense rainfall, with the inevitable consequence of extensive rockfalls, rockslides and debris flows.  Unfortunately, it appears that a tourist bus carrying 21 people was travelling down the highway at the time of the heaviest rainfall.  This bus, which was carrying 19 tourists from mainland China plus their driver and tour guide, is now missing.  The bus is likely to have been either buried by a rockslide or to have been involved in a landslide below the road, and thus to have been carried into the sea.  The likelihood of survival is very low.  Another tour bus was also involved in a rockslide, as shown in the image below (from here).

In this case the passengers escaped, but the driver and tour guide are also missing.  Finally, two other vehicles, and their three occupants, are also missing.

Meanwhile, a further nine people were killed in a landslide in Ilan, the main town to the north of the Suhua Highway, when a landslide hit a temple.