What is GIS?
The new source of power is not money in the hands of a few but information in the hands of many.
- John Naisbitt
GIS
What is GIS?
How To
Data Overview
Data Dictionary
Although maps have been used for thousands of years, it has only been in the last thirty five years that maps, graphics and databases have been combined with computers to create geographic information systems (GIS).
A simple definition of a geographic information system is one that links locations of places on the earth's surface to information describing the attributes of those places. GIS software uses georeferenced data to keep track of geographic features (such as town locations) and attributes associated with those features (such as the populations of those towns). Georeferenced data is information tied to specific locations on the earth through a system of real-world coordinates such as latitude and longitude. This information is stored in subject-specific data layers (such as towns, roads, eagle nests or mountain peaks). Multiple layers can then be combined into maps that tell a story about how these different subjects are related to each other geographically
History
A Short history of Conservation GIS
Over the years, GIS systems have evolved from layers of translucent paper maps, to large custom designed software packages on mainframe computers, to smaller, faster software applications on desktop UNIX workstations, to presently, simpler yet more powerful systems on desktop personal computers. Concurrently, the ranks of GIS users have expanded from highly trained technical staff to nearly anyone who deals with geographic data.
1800s: Map overlay techniques have been used since the American Revolutionary War, but became popular in 1800s, being used by the military, scientists and demographers. Cartographers used multiple layers of thin pieces of parchment or oil skin, to allow underlying map features to be visible.
1962: The first GIS system using digital data on a computer was developed in Canada, by Alan Tomlinson, called the Canadian Geographic Information System.
1969: Ian McHarg in his book "Design with Nature", popularized the use of georeferenced transparent map overlays for resource planning purposes. The Environmental Systems Research Institute (ESRI) is founded by Jack Dangermond.
1970 - mid 1980s: GIS systems are mostly custom designed software running on mainframe computers for use in facility management (utilities, etc.) and urban planning.
Mid 1970s: The Nature Conservancy's Natural Heritage Programs startup. These are the first standardized uses of geographically referenced biodiversity data. Data was kept on paper at first, and eventually in relational databases on computers. In the early 1990s, the databases were entered into Geographic Information Systems.
1978: ESRI releases the first version of Arc/Info, the current leading GIS software package.
1980s: The U.S. Forest Service uses massive amounts of primitive non-GIS computer modeling to do forest planning. Proprietary computer models only run on mainframe computers with little verification by the public and conservationists.
Late 1980s – early 1990s: Powerful UNIX workstations, while still expensive, become available on the desktop and replace most mainframe computers. GIS becomes widely available in big businesses, universities, government agencies and local planning offices.
1990: The 1980 census started the development of TIGER files for ease of use of data in mainframe computer applications. The 1990 census saw that demographic data collected could easily be used by GIS systems on a variety of smaller computer systems.
Early 1990s: The U.S. Fish and Wildlife Service, and later the National Biological Service start the Gap Analysis Program. This mapping program utilizes GIS and remote sensing to identify gaps in protected areas throughout the ecological communities of the United States. The U.S. Environmental Protection Agency uses GIS for Superfund management/toxic waste cleanup efforts. USGS/EPA starts the North American Land Change (NALC) Program utilizing GIS and satellite imagery to track changes in land use from the 1970s to the 1990s. ESRI begins it's Conservation Technology Support Program.
1994: The U.S. Forest Service begins deployment of GIS systems for the entire 186 million acre National Forest system, using Arc/Info and ArcView.
July 1995: ESRI releases ArcView 2.1 for the PC and Macintosh. Desktop computers become powerful enough to run GIS programs, making GIS analysis cheaply available for anyone interested in geographic problems.
