Vol.2-1 |
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空中写真で見る崩壊災害とその予知のための問題点
−とくに初生的大規模崩壊の地質構造規制について−
Hazardous Landslides Viewed on Aerial Photograph and Some Problems
in Their Prediction with Reference to Structural Control on Initiation
of Large Landslides
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平野 昌繁*
Masashige HIRANO* |
Abstract
It is now possible because of accumulation of aerial photographs over
30 years in Japan to discuss precisely the geomorphic features and geological
background of landslides with help of photo-interpretation. Distinction
of characteristics of landform associated with landcreep including slump,
debris-mud flow, and surface slide seems important even in this method.
Especially when initiation of large landslide is concerned, it is reasonable
to emphasize the geologic structure as one of the important controlling
factors of the phenomenon. Some of large landslides in the Kii Peninsula,
Kinki District, Japan, have occurred on the slopes shaped parallel to
stratification of Mesozoic sedimentary rocks which are inclined moderately
in this area. Secondary creep or slump of the soil delivered by the initial
slide has been observed rather frequently here. Therefore, it can be the
first step for prediction of the secondary mass movement to know the distribution
of the soil masses which are usually cultivated or populated in this mountainous
area. Mapping of the soil-mass distribution seems quite possible based
on photo-interpretation, and it is appreciated to start the mapping now,
as we have precise topographic maps and accumulated aerial photographs
of the area.
*大阪市立大学 地理学教室
Department of Geography, Osaka City University
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