Abstract
Risk evaluation to identify the occurrence of landslide has been performed so far mainly by the interpretation of aerial photograph, exploitation and observation at actual site. However, there are many problems in conventional method for evaluating wide area at uniform accuracy. One of the methods to solve such problems would be to utilize the remote sensing technology as an objective observation method. Remote sensing makes it possible to increase the contact points with GIS, and provide image analysis from comprehensive viewpoint using various image information over multiple dimensions.
This paper reports on the investigation made to specific area among the landslide area of Tertiary formation in Niigata prefecture using SPOT data, where we grasped the wide area from macro viewpoint and tried to study the possibility of extraction and renewal of landslide information.
This paper places primary focus on the analysis of information about the factors which cause the slide of land, taking advantages of the characteristics of remote sensing techniques, and is composed of the following study components.
(1) For the study area where the landslide occurred already, we tried to analyze the factors to have caused the landslide from the land conditions around there. (Step 1)
(2) Basing on the analysis result of factor information obtained in step 1, we tried to extract landslide points over the wide area using the overlay technique of images. (Step 2)
(3) Using the landslide points information obtained by step 2 and the information on the points of landslide already occurred, we tried to update the landslide distribution information applying overlay technique of images. (Step 3)
