AUTOMATED BUILDING DETECTION FROM HIGH-RESOLUTION SATELLITE IMAGE FOR UPDATING GIS BUILDING INVENTORY DATA

摘要

GIS building inventory data is a basic data to practice reliable earthquake damage assessment. In this study, a methodology of automated building detection from a high-resolution satellite image is proposed in order to update GIS building inventory data concisely. Newly constructed buildings not included in the GIS data are extracted from the difference between the image and the GIS data. Considering the location between a building edge and its shadow, the edge-based analysis is conducted to discriminate the building edge from others. We examine the applicability of the method using the IKONOS images in Yokohama city, Japan and Metro Manila, Philippines. The result shows that 90 % of mid-rise and high-rise buildings are detected successfully. The numbers of stories of the buildings are estimated using the shadow length in the image. The GIS building inventory data in Metro Manila is updated using the proposed method together with the land cover classification map. The building damage due to a scenario earthquake is assessed by means of simplified procedure based on the seismic capacity of the buildings and the computed ground motion. We compare the damage estimation between using the existing building inventory data and using the updated building inventory data. The result shows that the updated building inventory data provides more reliable damage estimation.