NOAA Office for Coastal Management (OCM) Coastal Inundation Digital Elevation Model: U.S. Virgin Islands

These data were created as part of the National Oceanic and Atmospheric Administration Office for Coastal Management's efforts to create an online

mapping viewer called the Sea Level Rise and Coastal Flooding Impacts Viewer. It depicts potential sea level rise and its associated impacts

on the nation's coastal areas. The purpose of the mapping viewer is to provide coastal managers and scientists with a preliminary look at sea

level rise (slr) and coastal flooding impacts. The viewer is a screening-level tool that uses nationally consistent data sets and analyses.

Data and maps provided can be used at several scales to help gauge trends and prioritize actions for different scenarios. The Sea Level Rise

and Coastal Flooding Impacts Viewer may be accessed at: http://www.coast.noaa.gov/slr

This metadata record describes the digital elevation model (DEM) for the U.S. Virgin Islands of St.Croix, St. John, and St. Thomas. This 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 described above. The DEMs created for this project were developed using the NOAA National Weather Service's Weather

Forecast Office (WFO) boundaries. The U.S. Virgin Islands DEM includes the best available data known to exist at the time of DEM creation, that met

project specifications for the U.S. Virgin Islands in the San Juan, PR WFO. This includes the coastlines of St. Croix, St. John, and St. Thomas.

This DEM was derived from the 2013 NOAA Topographic Lidar for the U.S. Virgin Islands. A hydro-flattened DEM created from this data was provided

by the contractor as a deliverable.

The DEM is referenced vertically to the Virgin Islands Vertical Datum (VIVD09) with vertical units of meters and horizontally to

the North American Datum of 1983 (NAD83). The resolution of the DEM is approximately 3 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.

10983

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: Virgin Island Vertical Datum of 2009 (VIVD09)

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 data. Horizontal accuracy testing is not performed on the DEM. Source data assumed to

meet 1 meter horizontal accuracy.

The DEM is derived from the source data. Vertical accuracy is not tested on the DEM. Project specifications require all source

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 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 coverage was incomplete.

Data covers the project area which includes the islands of the US Virgin Islands of St. Croix, St. John and St. Thomas.

Elevation data was checked for anomalous elevation values outside the expected range.