GIS Mapping
A geographic information system (GIS) allows us to view, understand, question, interpret, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts. Geographic information system (GIS) technology can be used for scientific investigations, resource management, and development planning. For example, a GIS might allow emergency planners to easily calculate emergency response times in the event of a natural disaster, or a GIS might be used to find wetlands that need protection from pollution.
What is a GIS?
A GIS is a computer system capable of capturing, storing, analyzing, and displaying geographically referenced information; that is, data identified according to location. Practitioners also define a GIS as including the procedures, operating personnel, and spatial data that go into the system.
How does a GIS work?
Relating information from different sources
The power of a GIS comes from the ability to relate different information in a spatial context and to reach a conclusion about this relationship. Most of the information we have about our world contains a location reference, placing that information at some point on the globe. When rainfall information is collected, it is important to know where the rainfall is located. This is done by using a location reference system, such as longitude and latitude, and perhaps elevation. Comparing the rainfall information with other information, such as the location of marshes across the landscape, may show that certain marshes receive little rainfall. This fact may indicate that these marshes are likely to dry up, and this inference can help us make the most appropriate decisions about how humans should interact with the marsh. A GIS, therefore, can reveal important new information that leads to better decisionmaking.
Nationwide GIS Mapping
GIS Mapping by State
Alabama
Alabama Metadata Portal
Alabama Water Quality Information System
Alaska
Alaska Geospatial Data Clearinghouse
Arizona
Arizona Electronic Atlas
Arkansas
Arkansas GIS Gateway
Arkansas AR-GAP
California
California Spatial Information Library (CaCIL)
California Land Use Planning Information Network (LUPIN)
Northern Sierra Nevada GIS
Colorado
Southwestern Colorado Data Center
Conneticut
Map and Geographic Information Center (MAGIC)
Connecticut Department of Environmental Protection
Delaware
Delaware Spatial Data Clearinghouse
Florida
Florida Geographic Data Library
Georgia
Georgia Spatial Data Infrastructure
Hawaii
City & County of Honolulu Dept. of Planning and Permitting
State of Hawaii Office of Planning GIS
Idaho
Inside Idaho
Idaho Department of Water Resources
Illinois
Illinois Natural Resources Geospatial Data Clearinghouse
Indiana
Indiana GIS Initiative
Iowa
Iowa Geographic Information Council (IGIC)
Kansas
Kansas Geospatial Community Commons
Kentucky
Kentucky Geological Survey
Kentucky Office of Geographic Information (KYGI)
Louisiana
Atlas: The Louisiana Statewide GIS
Louisiana Geographic Information Center (LAGIC)
Maine
Maine Office of GIS
Maryland
Maryland Historical Trust
Massachusetts
Massachusetts GIS
Michigan
Michigan Center for Geographic Information
Minnesota
Minnesota Geographic Data Clearinghouse
Minnesota Legislative Geographic Information Services
Mississippi
Mississippi Automated Resource Information System (MARIS)
Missouri
Missouri Spatial Data Information Service (MSDIS)
Montana
Natural Resource Information System (NRIS)
Nebraska
Nebraska Geospatial Data Bank
Nevada
Nevada Bureau of Mines & Geology
New Hampshire
New Hampshire GRANIT
New Jersey
New Jersey Geographic Information Network (NJIN)
New Jersey Dept. of Environmental Protection, GIS
New Mexico
New Mexico Resource Geographic Information System (RGIS)
New York
NYC OASIS
BYTES of the BIG APPLE
Cornell University Geospatial Information Repository (CUGIR)
NY State GIS Clearinghouse -
NYS Office of Cyber Security & Critical Infrastructure Coordination Orthoimagery Interactive Mapping Gateway
North Carolina
North Carolina Geographic Data Clearinghouse
NCSU Libraries County GIS Data
North Dakota
North Dakota Geographic Information Systems (NDGIS)
Ohio
Ohio Geographically Referenced Information Program (OGRIP)
Oklahoma
Oklahoma Center for Geospatial Information
Oklahoma State GIS Council
Oregon
Oregon Geographic Data Clearinghouse (OGDC)
Pennsylvania
Pennsylvania Spatial Data Access (PASDA)
Penn State University Libraries Maps & Data: Interactive Data Sources
Rhode Island
University of Rhode Island Natural Resource and Environmental Management
South Carolina
South Carolina Dept. of Natural Resources GIS Data Clearinghouse
South Dakota
South Dakota Geological Survey Program
Tennessee
Tennessee Spatial Data Server
TNMap
Texas
Texas Natural Resources Information System (TNRIS)
Texas Water Development Board
Utah
Utah GIS Portal
Vermont
Vermont Center for GIS (VGIC)
Virginia
Virginia Geographic Information Network
Washington
Washington State Geographic Information Council (WSGIC)
Washington State Dept. of Natural Resources GIS
West Virginia
West Virginia State GIS Technical Center
Wisconsin
Wisconsin Land INformation Clearinghouse (WISCLINC)
Wyoming
Wyoming Geographic Information Science Center