CONTINUOUS ASSESSING FOR THE RECOVERY AND RECONSTRUCTION OF POST-TSUNAMI DISASTER OF RIKUZENTAKATA CITY IN RIA COAST BY USING TIME SERIES HIGH RESOLUTION SATELLITE IMAGES

摘要

It is important to monitor the recovery and reconstruction process after the disaster for the long term for the following revival plans. Especially, a time series mapping of the change of condition and shape of land surface assessed in the high resolution is hoped for the reconstruction of post-disaster. Extensive damage occurred because of an earthquake on March 11, 2011 in eastern Japan, which generated a huge tsunami. Every municipal district town and village in the coastal regions of Iwate, Miyagi, and Fukushima Prefecture were damaged due to this tsunami. Especially, the town located in the ria coast fell into a catastrophic situation. The inundation was assessed so far by a lot of satellite and airborne sensing. Moreover, various struck situations immediately after disaster was investigated in detail. However, the case continuously assessed is few the recovery and reconstruction of the tsunami-devastated areas by using the high resolution satellite images in time series. In this study, the change in land cover for one and a half years after disaster were assessed by the high resolution satellite images in Rikuzentakata City located in the ria coast. The image data of multi spectral and the panchromatic images that had been observed in the time series by Worldview-2 and Quickbird satellite were used. A time series changes process of inundated area were pursued from the classification of the land cover and the operation between images. Especially, the change on the land surface after the inundation had disappeared was assessed in detail. Additionally, the recovery process of the shape of a public road and block has been quantitatively extracted by operating between images and filtering of edge detection. In addition, the changes in distribution of tsunami debris were shown by assessing the shape and roughness of the images. As a result, the recovery process was effectively made a map in Rikuzentakata City for one and a half years after tsunami disaster.