HR: 1340h
AN: OS23D-1342    [Abstracts]
TI: A Digital Elevation Model for Seaside, Oregon: Procedures, Data Sources, and Analysis
AU: * Venturato, A J
EM: Angie.J.Venturato@noaa.gov
AF: Joint Institute for the Study of the Atmosphere and Ocean (JISAO), University of Washington, Box 354235, Seattle, WA 98115 United States
AB: As part of a pilot study to modernize Flood Insurance Rate Maps for the Federal Emergency Management Agency (FEMA), a digital elevation model (DEM) was developed for the purpose of modeling tsunami inundation for Seaside, Oregon. The DEM consists of elevation data values with a horizontal grid spacing of 1/3 arc seconds, or approximately 10 meters. The DEM was generated from several topographic and bathymetric data sources, requiring significant processing challenges. These challenges included conversion to a single specified projection, units, horizontal datum, and vertical datum; analysis and removal of errant data from hydrographic, topographic, and LIDAR surveys; and a point-by-point analysis of overlapping data sources. Data were collected from the National Oceanic and Atmospheric Administration National Ocean Service and National Geophysical Data Center, the U.S. Geological Survey, the Oregon Geospatial Data Center, the University of Oregon, and the Oregon Department of Geology and Mineral Industries. Data were converted into formats compatible with ESRI ArcGIS 3.3 software. ArcGIS was used for spatial analysis, error correction, and surface grid development using triangular irregular networking. Post-processing involved a consistency analysis and comparison with original data and control data sources. The final DEM was compared with a previous DEM developed for tsunami inundation modeling in 1997. Significant shoreline differences were found between the DEMs, resulting in an analysis of the shoreline changes around the mouth of the Necanicum River. The shoreline analysis includes a spatial analysis of digital orthophotos over the recent past and a review of historical accretion and erosion rates along the Columbia River littoral cell.
DE: 3020 Littoral processes
DE: 3045 Seafloor morphology and bottom photography
DE: 3094 Instruments and techniques
DE: 3210 Modeling
DE: 0910 Data processing
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting