Journal of the Japan Society of Erosion Control Engineering, Vol.58,No.1,2005
Debris disasters caused by deep slope failures and debris flows triggered
by heavy rainfall
during Typhoon Aere in the east mountainous region of Hsinchu Prefecture,
Taiwan
Satoshi TSUCHIYA Takahisa MIZUYAMA Hiroshi IKEYA
Abstract
An unusually large number of typhoons visited Southeast Asia in 2004; 27 to the
beginning of December, and 10 hit just in Japan. Heavy rains caused serious debris|related
damage. Rainfall totaling over 1,000 mm caused many shallow and some deep slope
failures. In Taiwan, mountainous regions were also damaged severely by flash]floods
and landslides because of the heavy rains accompanying Typhoon Aere. And deep
slope failures causing debris flows measuring a million m3 killed 15 people in
the east mountainous region of Hsinchu Prefecture, Taiwan. If, as seems likely,
the sea temperature east of the Philippines remains high in the coming year, we
can expect many more and large typhoons to be generated. If so, there is a high
possibility of deep slope failures likely in Taiwan up to 10 times large as those
that occurred in Izumi]shi, Kagoshima Prefecture, and Minamata]shi, Kumamoto Prefecture,
Japan. The rainfall with largely amount and highly intensity could result in increased
the number and area size of slope failures, however, we have little knowledge
of enlarged deep slope failures. This paper describes debris disasters caused
by deep slope failures and debris flows triggered by the heavy rainfall during
Typhoon Aere from 23 to 25 August 2004 in the east mountainous region of Hsinchu
Prefecture, Taiwan.
Key words:Typhoon Aere, deep slope failure, debris flow, heavy rainfall, Taiwan
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