What is GIS?
Maps have been used for thousands of years, but it is only within the last few decades that the technology has existed to combine maps with computer graphics and databases to create geographic information systems or GIS.
GIS is used to display and analyze spatial data which are tied to a relational database. This connection is what gives GIS its power: maps can be drawn from the database and data can be referenced from the maps. When a database is updated, the associated map can be dynamically updated as well. GIS databases include a wide variety of information: geographic, social, political, environmental, and demographic.
GIS uses layers, called "themes," to overlay different types of information, much as some static maps use mylar overlays to add tiers of information to a geographic background. Each theme represents a category of information, such as roads or forest cover. As with the old mylar maps, the layers which are underneath remain visible while additional themes are placed above.
With the belief that these sophisticated technologies should not be the province of a privileged few, Inforain offers our research on the social, economic and environmental aspects of the coastal temperate rain forest and maintains a database of GIS layers available for download.
Freely downloadable GIS applications include the open-source GRASS GIS for Linux or Mac, or introductory ArcExplorer developed by the Environmental Systems Research Institute (ESRI).
