Journal of the Japan Society of Erosion Control Engineering, Vol.59,No.2,2006
Potential site prediction of deep]seated landslide on the western flank
of Mt. Yahazu]dake,
Izumi City, Kagoshima Prefecture, Japan
Takashi JITOUSONO Etsuro SHIMOKAWA Yukiyoshi TERAMOTO
Abstract
A deep]seated landslide occurred in the Harihara River basin on the western flank
of Mt. Yahazu]dake, the Pliocene volcano, in Izumi City, Kagoshima Prefecture
on July 10, 1997. This deep]seated landslide was caused by rising of groundwater
level associated with heavy rainfall, the hydrogeomorphological formation of the
underground area prone to storage of groundwater, and deeply weathered volcanic
rocks. This study aimed to develop a method for potential site prediction of deep]seated
landslide. Some indicators for ascertaining such sites were examined based on
topographical and geological surveys, along with hydrological observations in
four watersheds on the western flank of Mt. Yahazu]dake. It was ascertained that
effective indicators for predicting potential site of deep]seated landslide were
the patial distributions of gentle slopes, boundaries between aquifer and aquiclude,
the change points of stream discharge, electric conductivity, and silica concentrations
along a longitudinal stream, and the distribution of springs.
Key words:deep]seated landslide, potential site prediction of landslide, hydrogeomorphology,
Izumi City
Japan Society of Erosion Control Engineering
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