Wisconsin Coastal GIS Applications Project

Coastal GIS Data

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This web site provides two types of information to the user.  First, users will find summaries of the various types of digital spatial data that may be used in coastal GIS applications.  Second, users will find links to federal and state government sites that contain salient data for Wisconsin's coastal counties. 

Summary of Spatial Data Types
Links to Spatial Data Web Sites

Summary of Spatial Data Types

Digital orthophotos are aerial photographs with tilt and relief displacement removed from them (i.e., they are planimetrically correct).  Therefore, ground features displayed on the orthophoto are in their true ground location.  Direct measurement of distances, angles, and areas from the orthophotos may occur because orthophotos are planimetrically correct.  Digital orthophotos are generally available in black-and-white and color infrared with 1-meter ground resolution.  Orthophotos are incredibly useful GIS layers.  They are often used as backdrops for vector data like roads, hydrography, and parcels, and as a tool for updating and collecting vector data.  For more information on digital orthophotos, check out the following web sites:

 USGS metadata for digital orthophotos
 Digital orthophoto fact sheet
 To order digital orthophotos, check the Global Land Information System

Digital Raster Graphics (DRGs), produced by USGS, are scanned, geo-referenced USGS standard series topographic maps.  DRGs are also used as backdrops for vector data, and they are used to revise and collect digital data. The Land Information and Computer Graphics Facility has processed the DRGs that lie along the Lake Michigan and Lake Superior shore here in Wisconsin. Click  here to see a map of the DRGs available from LICGF and to learn more about the processing performed on them.  For more information on digital raster graphics, check out the following web sites:

 DRG Program Information
 DRG fact sheet
 To order digital raster graphics, check the Global Land Information System
Digital Elevation Models (DEMs) are data sets comprised of terrain elevations for ground positions at regularly spaced horizontal intervals.  The highest resolution DEMs available for the United States are the 7.5 minute DEM series available from the USGS.  This series has a resolution of 30 meters (i.e., the interval between each ground point is 30 meters).  While this resolution is sufficient for watershed delineation and other such tasks, we believe it is too coarse to be used in coastal applications.  For more information on digital elevation models, check out the following web sites:

 USGS metadata for DEMs
 DEM fact sheet
 To obtain free 1:250,000 DEMs, check US GeoData
 To order any other DEMs, check the Global Land Information System

Digital Line Graphs (DLGs) are digital vector files representing cartographic information.  USGS derived these files from aerial photographs and hard copy maps using manual and automated digitizing methods.  Large-scale DLGs are produced in 7.5" units that correspond to 1:24,000 topographic quadrangles.  Features represented in the large-scale DLGs include political boundaries, hydrography, Public Land Survey System, transportation, hypsography (elevation), vegetative surface cover, nonvegetative surface cover, and survey control and markers.  DLGs are also available in 1:100,000 scale and 1:2,000,000 scale versions.  For more information on digital line graphs, check out the following web sites:

 USGS metadata for DLGs
 DLG fact sheet
 To obtain free large-scale, 1:100,000, and 1:2,000,000 DLGs, check US GeoData

TIGER (Topologically Integrated Geographic Encoding and Referencing System), developed by the U.S. Census Bureau to support the decennial census, is a geographic database that covers the entire United States. The Census Bureau, along with USGS, created the TIGER database in the 1980s. The USGS scanned roads, railroads, hydrography, and transportation layers from 1:100,000 USGS topographic maps. Then, the Bureau integrated the layers into one topologically consistent file. For the urban areas, the GBF/DIME files created in the 1970s and updated in the 1980s were integrated into the TIGER database. The public can order a product called TIGER/Line files from the Bureau or other vendors. These line files, extracted from the TIGER database, contain the boundaries of legal, administrative, and statistical areas for every county, parish, borough, and census geographic area in the U.S., U.S. Virgin Islands, Puerto Rico, Hawaii, and the Pacific Island Territories.  Alternatively, some of the TIGER/Line files can be downloaded free of charge from the Internet. For more information on TIGER or to download TIGER/Line files, check out the following web sites:

 The TIGER Page at the Census Bureau
 Archive of Census Related Products (including 1992 TIGER data)
 DDCarto (Demographic Data Cartogram Service) --Download Census data in Atlas GIS, ARC/INFO, or MapInfo format for every county in Wisconsin

The Wisconsin DNR Geographic Services section has 5 CD-ROMs of digital spatial data available for purchase.  here to learn more about the CD-ROMs, including instructions for ordering the discs, from DNR.

Links to Spatial Data Web Sites

The WISConsin Land Information CLearinghouse provides a "gateway to geospatial data and metadata, related land and resource information, and the Wisconsin agencies which produce or maintain them. WISCLINC allows the user to search the Wisconsin Clearinghouse for digital spatial data of Wisconsin. Although the data may not be available from the Clearinghouse, the metadata usually includes information for obtaining it. As for free data, download the following state data sets in ARC/INFO shapefile format (.shp) or Graphics Interchange Format (.gif): county boundaries, hydrography, school districts, roads, and tribal lands.
Wisconsin Dept. of Natural Resources Geographic Services Section
This web site contains valuable information on statewide data sets held by the Wisconsin DNR. Click here to see a listing of statewide Wisconsin DNR GIS data layers. Click here to see a list of transitional GIS data sets for Wisconsin. The DNR does not have statewide coverage for these data sets yet. This site also provides users with mechanisms for obtaining these data sets (e.g., cd-rom, tape, or diskette).
USGS Node of the National Spatial Data Infrastructure Clearinghouse
This site allows the user to browse all geospatial data available from USGS. Users can browse the "Best Sellers," the most popular USGS geospatial data products; the Product Category, an alphabetical listing of all major categories of USGS geospatial data; or by Theme, a categorization by topic.
USGS Global Land Information System
This site allows the user to browse all data products currently available from USGS. It can help the user determine if the data they seek is available (e.g., whether or not a county's digital orthophoto is finished). It also allows users to order geospatial data from USGS. The GLIS has an especially useful user interface.
US GeoData
This site allows the user to download free geospatial data from the EROS Data Center. Available data sets include 1:250,0000 digital elevation models (DEMs) for the entire United States, 1:2,000,000 scale digital line graphs (DLGs) in SDTS format for the entire United States, 1:100,000 and 1:24,000 scale DLGs for sections of the U.S. (status maps show the sections of the country for which data is available), and 1:250,000 and 1:100,000 scale land use and land coverage (LULC) for the country.
USDA Natural Resources Conservation Service Data Resources(NRCS)
The NRCS distributes soils, plants, and natural inventory data to the general public for free on a nominal fee (depending on the product). The Soil Survey Geographic Database (SSURGO) will eventually contain soils coverages for every county in the United States. Click here to check the status map for this project.
This web site allows users to obtain data produced and distributed by NOAA. Use the keywords "medium resolution shoreline" to obtain medium resolution shoreline data for the U.S.

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Last modified by David Hart on August 30, 2000. Originally developed by David Van Riper in .