Vol.8-1
 
地形情報を用いた地すべり危険地域の判別
Discrimination of Landslide Risk Area by Topographic Information
吉澤 孝和* ・ 渡辺欣之**
Norikazu YOSHIZAWA* and Yoshiyuki WATANABE**

 

Abstract
 An examination using data for two districts was made of the applicability, to the discrimination of landslide-prone areas, of a quantification-method-II treatment of six quantities which are obtainable from a topographic map and likely to be related to landslides. The six quantities are elevation, slope inclination, depth from the summit level,height above the river level, relative relief, and valley density. The two districts are the drainage basins of the Sai and Dojiri rivers in the northern part of Nagno Prefecture. A large number of landslides have occurred in these districts. Data were collected from each 5-mm grid square laid on the l/25,000 topographic map Shinanonakajo.The discrimination for the two districts showed a reliability of 70%, as judged from a comparison with actual landslide data. Of the six quantities, elevation, valley density, and height above the river level had major contributions to the discrimination.

【キーワード】:地すべり,地形図,地形的要因,危険地域判別,数量化理論II類


*信州大学工学部土木工学科
Department of Civil Engineering, Faculty of Engineering, Shinshu University
**兵庫県立白鷺工業高等学校
Hakuro Technical High School, Hyogo Prefecture


日本自然災害学会