DETECTING FLOODED LOCATION USING SAR DATA AND ASSESSMENT OF POST-FLOODED CONDITION

摘要

The aim of this study is to detect flooded location using SAR data and assessment of post-flooded conditions using a Geographic Information System (GIS) and SAR (Synthetic Aperture Radar) data images.The temporal characteristics of radar response form flooded were analyzed throughout the 2002summer flooded season.Flooded locations were identified by change detection technique of RADARSAT SAR data images. Multiple scenes of Radarsat SAR images were acquired before, during, and after the flood inundation. From the interpretation of colour composite imagery of the multi-temporal SAR data, as well as from the temporal profiles of radar backscatter, seven types of Landcover were separable according to flooded and post-flooded recovery conditions. Landover map of 2000.07 was classed 7 categories by water, urban, bare ground, marsh, grassland, forest and farming.As results, farming area showed 14.52km~2, forest flooded area showed 3.50km~2, %, grassland flooded area showed 1.06km~2, ground flooded area was accounted for 0.09km~2and urban flooded area showed 0.04km~2.The actual flooded damage to the standing farming crop depends on the duration of the flood and on subsequent recovery status. We found that image data acquired during and after flooded is necessary to assess accurately flood damage to farming area.From now on, this study will contribute to reduce the hazardous of natural disasters and to raise the pliability in the process of managing damage of natural disasters.