Wabash River at Memorial Bridge, Vincennes, Indiana, Flood-Inundation Geospatial Data Sets and Metadata

Digital flood-inundation maps for a 10.2-mile reach of the Wabash River at Memorial Bridge at Vincennes, Indiana, were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the Wabash River at Memorial Bridge at Vincennes, Indiana (station number 03343010). Near-real-time stages at this streamgage may be obtained from the USGS National Water Information System at http://waterdata.usgs.gov/ or the National Weather Service (NWS) Advanced Hydrologic Prediction Service at http://water.weather.gov/ahps/, which also forecasts flood hydrographs at this site (VCNI3). Flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The hydraulic model was calibrated by using the most current stage-discharge relation at the Wabash River at Memorial Bridge at Vincennes, Ind., streamgage. The calibrated hydraulic model was then used to compute 19 water-surface profiles for flood stages referenced to the streamgage datum and ranging from 10.0 feet, or near bankfull, to 28 feet, the highest stage of the stage-discharge rating curve. The simulated water-surface profiles were then combined with a Geographic Information System digital elevation model (derived from light detection and ranging [lidar] data having a 0.98-foot vertical accuracy and 4.9-foot horizontal resolution) to delineate the area flooded at each water level.