Method Development of Land Cover Change Detection by Typhoon RUSA

태풍 RUSA 전.후의 토지피복변화 분석기법 연구

This study is to present a method of land cover change detection by the typhoon RUSA (August 1 - September 4, 2002) using Landsat 7 ETM+ images. For the Namdae-cheon watershed in Gangreung, two images of Sept. 29, 2000 and Nov. 22, 2002 were prepared. To identify the damaged areas, firstly, the NDVI (Normalized Difference Vegetation Index) of each image was computed, secondly, the NDVI values were reclassified as two categories that the negative index values including zero are the one and the positive index values are the other, thirdly the reclassified image before typhoon is subtracted from the reclassified image after typhoon to get DNDVI (Differential NDVI). From the DNDVI image, the flooded and damaged areas could be extracted.