MODELING FLOODPLAIN INUNDATION USING AN INTEGRATED GIS WITH RADAR ANDOPTICAL REMOTE-SENSING

Synthetic aperture radar images from multitemporal L-band JERS-1 and C -band ERS-1 satellites, a Landsat Thematic Mapper (TM) time-series, an d GIS coverages were used in an integrative approach to model the pote ntial of flood inundation within the lower Roanoke River floodplain, N orth Carolina. A digital elevation model (DEM) with one-meter vertical resolution was developed for the region from scan-digitized mylar sep arates of contour lines on USGS 7.5-min quadrangles. Several models re presenting potential wetness and potential flood inundation were gener ated from the DEMs using both raster (grid) and vector (network) analy ses. The potential inundation surfaces were derived from regression mo dels that related known flood elevations to river position and floodpl ain location. The GIS models were assessed by comparison to classifica tions of flood change-detection achieved through the radar data. Stati stical results indicate that the GIS-derived models successfully ident ified flooded areas as mapped by the radar change-detections. Further, statistical tests assessed the ability of individual radar and optica l (Landsat TM) images to discriminate flooding as predicted by the GIS models. Both JERS-1 and ERS-1 images identified areas of inundation a t different flood levels. (C) 1998 Elsevier Science B.V.