EXAMINATION OF THRESHOLD CORRECTION METHOD FOR EXTRACTION OF LANDSLIDE DISASTER AREAS USING DIFFERENCE IMAGES BY HIGH-RESOLUTION SATELLITE

Abstract

 Due to heavy rain in northern Kyushu in July 2017 and the Eastern Hokkaido Iburi Earthquake in 2018, many landslide disasters occurred in a wide area. Satellite remote sensing technology is effective when it is difficult to identify disaster spots in a wide area or to approach a mountainous area immediately after a disaster. In this study, in order to extract landslide disaster areas based on differential images of high-resolution satellites before and after the disaster, a threshold correction method was considered to separate disaster areas and non-disaster areas taking into account the land cover of the affected areas. In addition, in order to more appropriately evaluate the extraction accuracy of disaster areas by satellite image processing, evaluation was performed based on reference data corrected by visual interpretation of satellite images after the disaster. As a result, the accuracy improvement by the threshold correction method here was shown. In addition, by using both GIS technology for pixel complementation of analysis results and slope information of the affected areas, erroneous extraction of landslide disaster areas was reduced.