NOAA Office for Coastal Management Coastal Inundation Digital Elevation Model: Portland (OR) WFO - Tillamook, Lincoln, and Lane 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 - Tillamook, Lincoln, and Lane Counties. The DEM includes the best available

lidar data known to exist at the time of DEM creation for the coastal areas of Tillamook, Lincoln, and Lane 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 Oregon

Department of Forestry (ODF). LiDAR data for Lane, Lincoln, and Tillamook counties, was collected for DoGAMI and ODF from 2007 through 2009.

Note that the Tillamook Bay area (2007 ODF data) was added to the original 2012 DEM in December 2014. Hydrographic breaklines used in the creation of the

DEM were delineated using LiDAR intensity imagery generated from the DoGAMI and ODF 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 Office for Coastal Management has developed high-resolution digital elevation models (DEMs) for use in the Office'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.

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Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.0000001

Longitude_Resolution: 0.0000001

Geographic_Coordinate_Units: Decimal degrees

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsoid_Name: Geodetic Reference System 80

Semi-major_Axis: 6378137.000000

Denominator_of_Flattening_Ratio: 298.257222101

Vertical_Coordinate_System_Definition:

Altitude_System_Definition:

Altitude_Datum_Name: North American Vertical Datum of 1988

Altitude_Resolution: 0.001

Altitude_Distance_Units: meters

Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates

Any conclusions drawn from the analysis of this information are not the responsibility of the Office for Coastal Management

or its partners.

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.

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.

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.

Data covers the project area, defined as the WFO boundary. Elevation data checked for anomalous elevation

values outside expected range.