Digital Elevation Model (DEM) is the terminology adopted by the USGS to describe terrain elevation data sets in a digital raster form. The standard DEM consists of a regular array of elevations cast on a designated coordinate projection system. 1-degree DEMs (3- by 3-arc second data spacing) provides coverage in 1- by 1-degree blocks. The basic elevation model is produced by or for the Defense Mapping Agency (DMA), but is distributed by the USGS in the DEM data record format. Coverage is for the United States.

The US EPA 1-degree DEM shapefiles are polygonal representations of the original USGS DEM raster files resampled to a 300m x 300m cell size. Catolog Units (CU)in each of the ten US EPA Regions were buffered by a two mile distance. The buffered CUs were used to clip corresponding areas from the DEM raster files. The resulting files were output in Environmental Systems Research Institute's (ESRI) shapefile format. Two attribute fields were added to each shapefile's database component to represent elevation in both meters and feet.

Contact_Address:

Address_Type: mailing address

Address: 401 M Street, SW Mailstop 4305

City: Washington

State_or_Province: District of Columbia

Postal_Code: 20460

Agiencypartington.ed@epa.gov. 

Northeast Ohio Environmental Data Exchange Network Maxine Goodman Levin College of Urban Affairs
Cleveland State University
1737 Euclid Avenue
Cleveland, OH 44115

phone: (216) 687-2134
fax: (216) 687-9277