Landslides feared on Chiang Rai fault

BANGKOK: -- Chiang Rai’s Mae Chan geologic faults may trigger landslides, the Mineral and Geologic Resources department (MGR) warned yesterday.

If heavy rains continue to pour, people living there may have to be evacuated, it said.

Meanwhile, residents in Ubon Ratchathani became panicky after a road broke up and left a 100-metre crack. They feared that the road surface had collapsed.

The landslide warning came after a seminar on geological alarm networking was attended by more than 600 volunteers from four districts in Chiang Rai.

Houses and most of the roads in the districts are built on eroded granite land that is no longer covered by forests.

“The Mae Chan fault runs from Fang district in Chiang Mai parallel to Mae Chan Creek and Kiu Satai-Mae Chan Road to the Mekong River in Chiang Saen district. Both sides of the road are flanked by steep slopes or cliffs, making it prone to landslides,” said MGR director-general Somsak Phothisat.

MGR technician Somjai Yensabai said that in September last year heavy rains in Mae Chan district had caused a mudslide that buried houses and schools, causing two deaths.

When 60 millimetres of rain per day is recorded, it is necessary to watch out for landslides.

When precipitation exceeds 100 millimetres, preparation must be made for an evacuation. When continuous rains exceed 300 millimetres after many days, an immediate evacuation is necessary.

Meanwhile Boonma Boonraksa, 67, from tambon Kutlat in the Muang district of Ubon Ratchathani, said he had heard a loud explosion that shook his house at midday on Friday while watching television.

He went out to locate the cause of the noise with other residents and found a crack in the road one metre away from his house.

The crack was 100m long. He also found a crack in the wall of his house. He feared subsidence had occurred.

--The Nation 2005-07-17

I am not a geologist but this 'landslide is caused by earthquakes' is getting repeated alot these days. The usual cause of landslides is deforestation. Deforestation causes excess runoff after a rain. Deforestation of slopes kills the roots that hold the dirt in place...so it is less stable and prone to movement. Deforestation benefits rich people mostly so I guess the rich people in Thailand have found a way to divert public attention from their misdeeds and direct it toward the boogie man 'earth tremor'....but I could be wrong about this as I said in the opening, I am not a geologist.