The scale of disaster and its prediction by large landslide casued by earthquake around town

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We studied mainly debris flow in Fujiwara-cho which had occurred acceleration of 342gal and and damage of landslide caused by Chi-Chi(集集) earthquake which had occurred acceleration 982gal.1. Surveying of the debris flow in Fujiwara-choThe debris flow occurred at Nishinogaito-stream and kotaki-stream in Fujiwara-cho(藤原町) on July 2002. There was no human damage by the debris flow according to the existence of extended series of check dams after the previous debris flows occurred on Aug. 19, 1999. The sediment yield at Nishinogaito-stream was 27 thousand m^3 from sedimentation amount to 4th check dam. This amount was about 4 times of the sediment yields (4-5 thousands m^3)2. Surveying in landslide Taiwan Chiu-chiu-feng-shan and Tsao-linga. We heard about the nocturnal conditions concerning of the Chi-Chi earthqwake and landslide on Chiu-chiu-feng-shan(九〓二山) slope from a parson(Mr.官) lived face to face with the slope of landslide on Dec. 24, 2002. The Basic data of colluvial deposit was measured from soil of soil sampler A(598 cm^3) which is No.1-2 and soil sampler B(400 cm^3) that is No.3-5. The unit weight of the soil was 1.58-1.59 gf/cm^3. The permeability test was carried on the soil of colluvial deposit. The coefficient of permeability was 2.63×10^<-5> in the unsaturated condition.b. We heard about the condition of landslide at the earthquake from a parson (Mr.簡) lived on top of the slope of Tsao-ling(草嶺), and a parson lived on the right bank of the branch(清水渓) of Choshui-Hsi river below the slope.