NOAA Office for Coastal Management Coastal Inundation Digital Elevation Model: Portland (OR) WFO - Clatsop, Columbia, and Multnomah Counties

This digital elevation model (DEM) is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Office for Coastal Management's Sea Level Rise and Coastal Flooding Impacts Viewer. The DEMs created for this project were developed using the NOAA National Weather Service's Weather Forecast Office (WFO) boundaries. Because the WFO boundaries can cover large areas, the WFO DEM was divided into smaller DEMs to ensure more manageable file sizes. The Portland (OR) WFO DEM was split into two smaller DEMs. They are divided along county lines and are: 1. Portland (OR) WFO - Tillamook, Lincoln, and Lane Counties 2. Portland (OR) WFO - Clatsop, Columbia, and Multnomah Counties This metadata record describes the DEM for the Portland (OR) WFO - Clatsop, Columbia, and Multnomah Counties. The DEM includes the best available lidar data known to exist at the time of DEM creation for the coastal areas of Clatsop, Columbia, and Multnomah counties, that met project specifications. Please note that the Portland WFO boundary extends into Washington state. The Washington portion of the WFO is also available for download from NOAA OCM as a separate product. The DEM is derived from LiDAR datasets collected for the Oregon Department of Geology and Mineral Industries (DoGAMI) and the U.S. Army Corps of Engineers (USACE). LiDAR data for a portion of Clatsop County, was collected for DoGAMI in 2008-2009. LiDAR data along the Columbia River in Clatsop, Columbia and Multnomah counties was collected for USACE in 2010. Hydrographic breaklines used in the creation of the DEM were delineated using LiDAR intensity imagery generated from the DoGAMI datasets and were also obtained from USACE. The DEMs are hydro flattened such that water elevations are less than or equal to 0 meters. The DEM is referenced vertically to the North American Vertical Datum of 1988 (NAVD88) with vertical units of meters and horizontally to the North American Datum of 1983 (NAD83). The resolution of the DEM is approximately 5 meters.