Abstract
Floodplain Auto-Delineation Using LIDAR Data Track: Water Resources Author(s): Tolga Yilmaz The Illinois State Water Survey is using an autodelineation method for the map modernization program when newer, higher-resolution terrain data (LIDAR) are available. The autodelineation method depicts the 100- and 500-year floodplain boundaries of studied streams in an accurate and efficient way and increases the quality of the Digital Flood Insurance Rate Map (DFIRM) product. ArcGIS and the 3D Analyst and Spatial Analyst extensions are extensively used in the five primary steps for floodplain autodelineation: (a) creating a DEM from the water surface elevation, (b) creating a DEM from the terrain elevation, (c) subtracting the terrain elevation DEM from the water surface elevation DEM, (d) converting the result into vector amd (e) postprocessing the lines. These steps will be explained in detail, and examples from Kane and Cook counties will be given in the presentation. Tolga Yilmaz Illinois State Water Survey CENTER FOR WATERSHED SCIENCE 2204 Griffith Dr. Champaign , IL 61820 US Phone: 217-265-9432 E-mail: tyilmaz@uiuc.edu |
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