Converting a NEXRAD Rainfall Map into a Flood Inundation Map by ...

The more specific steps for the post-processing phase in charge of theflood map delineation are shown and have been incorporated into the Map2Mapworkflow by means of standard geoprocesses in Arc GIS 9 and customized scripttools to achieve the post-processing steps needed for flood inundation mapping.• The HEC-RAS ASCII export SDF file is converted to XML format forGIS assimilation• The Elevations in XML format are associated with cross sections inArc Hydro• The elevations along the cross sections are used for interpolation andgeneration of a water surface TIN• The water surface TIN is clipped to the floodplain boundary• The water surface TIN is converted to raster format• The water surface raster in intersected with the terrain raster toproduce a water depth raster• The water depth raster is converted to polygon format• The water depth polygon is dissolved to generate the flood inundationmapFigure 3.25 illustrates the schematic sequence for the above floodplaindelineation steps67