Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC) 2012 Raster Charleston, SC NOAA's Ocean Service, Coastal Services Center (CSC) http://www.csc.noaa.gov/digitalcoast/tools/slrviewer http://www.csc.noaa.gov This digital elevation model (DEM) is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Coastal Services Center'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 CSC 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. The NOAA Coastal Services Center has developed high-resolution digital elevation models (DEMs) for use in the Center's Sea Level Rise And Coastal Flooding Impacts internet mapping application. These DEMs serve as source datasets used to derive data to visualize the impacts of inundation resulting from sea level rise along the coastal United States and its territories. All datasets used to construct this DEM are publicly available via the NOAA Coastal Services Center's Digital Coast (www.csc.noaa.gov/lidar). Further information regarding the constituent lidar datasets of this DEM can be accessed using the following url's: http://csc.noaa.gov/dataviewer/webfiles/metadata/or2009_dogami_north_coast_template.html http://csc.noaa.gov/dataviewer/webfiles/metadata/or2010_usace_columbia_river_template.html 2008 2010 ground condition Complete None planned -124.160863802 -121.819108802 46.3000189404 45.4316089404 ISO 19115 Topic Category elevation None Bathymetry/Topography elevation Digital Elevation Model DEM lidar inundation flooding lidar topography sea level rise None US Oregon Clatsop County Columbia County Multnomah County None The dataset is provided "as is," without warranty to its performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of this dataset is assumed by the user. This dataset should be used strictly as a planning reference and not for navigation, permitting, or other legal purposes. Acknowledgment of the NOAA Coastal Services Center as a data source would be appreciated in products developed from these data, and such acknowledgment as is standard for citation and legal practices for data source is expected. Data covers the project area, defined as the WFO boundary. Elevation data checked for anomalous elevation values outside expected range. A visual qualitative check was performed to ensure data completeness. All available lidar data known at the time of DEM creation that meets project specifications has been used to develop the DEM. Known data gaps may exist where lidar coverage was incomplete. The DEM is derived from the source lidar data. Horizontal accuracy testing is not performed on the DEM. Lidar source data assumed to meet 1 meter horizontal accuracy. The DEM is derived from the source lidar data. Vertical accuracy is not tested on the DEM. Project specifications require all source lidar data used in constructing the DEM to meet FEMA Specifications for Flood Hazard Mapping. NOAA Coastal Services Center 2012 http://www.csc.noaa.gov/dataviewer/ http://csc.noaa.gov/dataviewer/webfiles/metadata/or2009_dogami_north_coast_template.html http://csc.noaa.gov/dataviewer/webfiles/metadata/or2010_usace_columbia_river_template.html online digital data 2008 2010 ground condition CSC lidar Lidar points covering portions of Clatsop, Columbia and Multnomah counties were used in developing the DEM. 1. Lidar source data and hydrographic breaklines were obtained and imported into an ESRI ArcGIS file geodatabase for each constituent county within the WFO boundary. Only ground classified lidar (Class 2) points were used to reflect a bare earth surface. Hydrographic features were assigned elevation values at or below 0 meters. An ESRI Terrain was then generated from these source data. 2. The ESRI Terrain was converted to a DEM (Erdas Imagine .img file format) with a cell size of 3 meters. The DEM was reviewed in Global Mapper for incorrect elevations and artifacts introduced from source inputs or during the raster creation process. Corrections were applied to the DEM and reprocessed for further review. 3. All DEMs for the entire study area (WFO) were loaded into Global Mapper for a final review. The constituent DEMs were then checked to ensure complete coverage within the study area and that no issues existed along the boundary between adjacent DEMs. Once it was determined all DEMs were seamlessly edge-matched and no other artifacts were present, the constituent DEMs were mosaiced together, resampled to 5m and reprojected to the NAD83 geographic coordinate system. CSC lidar 2012 Raster Grid Cell 19298 52039 1 0.0000001 0.0000001 Decimal degrees North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222101 North American Vertical Datum of 1988 0.001 meters Explicit elevation coordinate included with horizontal coordinates NOAA Coastal Services Center mailing and physical

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Charleston SC 29405-2413 843-740-1202 csc.info@noaa.gov Downloadable Data Any conclusions drawn from the analysis of this information are not the responsibility of the Coastal Services Center or its partners. 20131108 NOAA Coastal Services Center mailing and physical

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Charleston SC 29405-2413 843-740-1202 csc.info@noaa.gov FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998