Geographic information system - Wikipedia, the free encyclopedia. From Wikipedia, the free encyclopedia. A geographic information system (GIS), also known as a geographical information system, captures, stores, analyzes, manages, and presents data that refers to or is linked to location.
In the strictest sense, the term describes any information system that integrates, stores, edits, analyzes, shares, and displays geographic information. In a more generic sense, GIS applications are tools that allow users to create interactive queries (user created searches), analyze spatial information, edit data, maps, and present the results of all these operations. Geographic information science is the science underlying the geographic concepts, applications and systems, taught in degree and GIS Certificate programs at many universities.[edit]Applications. Geographic information system technology can be used for scientific investigations, resource management, asset management, archaeology, environmental impact assessment, urban planning, cartography, criminology, geographic history, marketing, and logistics to name a few. For example, GIS might allow emergency planners to easily calculate emergency response times in the event of a natural disaster, GIS might be used to find wetlands that need protection from pollution, or GIS can be used by a company to site a new business location to take advantage of a previously under- served market.[edit]History of development. About 1. 5,5. 00 years ago [1], on the walls of caves near Lascaux, France, Cro- Magnon hunters drew pictures of the animals they hunted.[2] Associated with the animal drawings are track lines and tallies thought to depict migration routes.
While simplistic in comparison to modern technologies, these early records mimic the two- element structure of modern geographic information systems, an image associated with attribute information.[3]In 1. John Snow depicted a cholera outbreak in London using points to represent the locations of some individual cases, possibly the earliest use of the geographic method.[4] His study of the distribution of cholera led to the source of the disease, a contaminated water pump (the Broad Street Pump, whose handle he disconnected terminating the outbreak) within the heart of the cholera outbreak.
While the basic elements of topology and theme existed previously in cartography, the John Snow map was unique, using cartographic methods not only to depict but also to analyze clusters of geographically dependent phenomena for the first time. The early 2. 0th century saw the development of "photo lithography" where maps were separated into layers. Computer hardware development spurred by nuclear weapon research would lead to general purpose computer "mapping" applications by the early 1. The year 1. 96. 2 saw the development of the world's first true operational GIS in Ottawa, Ontario, Canada by the federal Department of Forestry and Rural Development.
Developed by Dr. Roger Tomlinson, it was called the "Canada Geographic Information System" (CGIS) and was used to store, analyze, and manipulate data collected for the Canada Land Inventory (CLI)—an initiative to determine the land capability for rural Canada by mapping information about soils, agriculture, recreation, wildlife, waterfowl, forestry, and land use at a scale of 1: 5. A rating classification factor was also added to permit analysis. CGIS was the world's first "system" and was an improvement over "mapping" applications as it provided capabilities for overlay, measurement, and digitizing/scanning. It supported a national coordinate system that spanned the continent, coded lines as "arcs" having a true embedded topology, and it stored the attribute and locational information in separate files.
As a result of this, Tomlinson has become known as the "father of GIS," particularly for his use of overlays in promoting the spatial analysis of convergent geographic data.[6] CGIS lasted into the 1. Canada. It was developed as a mainframe based system in support of federal and provincial resource planning and management. Its strength was continent- wide analysis of complex datasets. The CGIS was never available in a commercial form.
In 1. 96. 4, Howard T Fisher formed the Laboratory for Computer Graphics and Spatial Analysis at the Harvard Graduate School of Design (LCGSA 1. SYMAP', 'GRID', and 'ODYSSEY' - - which served as literal and inspirational sources for subsequent commercial development - - to universities, research centers, and corporations worldwide.[7]By the early 1. M& S Computing (later Intergraph), Environmental Systems Research Institute (ESRI) and CARIS (Computer Aided Resource Information System) emerged as commercial vendors of GIS software, successfully incorporating many of the CGIS features, combining the first generation approach to separation of spatial and attribute information with a second generation approach to organizing attribute data into database structures. In parallel, the development of two public domain systems began in the late 1. MOSS, the Map Overlay and Statistical System project started in 1. Fort Collins, Colorado under the auspices of the Western Energy and Land Use Team (WELUT) and the US Fish and Wildlife Service.
GIS was begun in 1. U. S. Army Corp of Engineering Research Laboratory (USA- CERL) in Champaign, Illinois, a branch of the U. S. Army Corps of Engineers to meet the need of the United States military for software for land management and environmental planning. The later 1. 98. 0s and 1. GIS on Unix workstations and the personal computer. By the end of the 2.
GIS data over the Internet, requiring data format and transfer standards. More recently, there are a growing number of free, open source GIS packages which run on a range of operating systems and can be customized to perform specific tasks.[edit]Techniques used in GIS[edit]Data creation.
Modern GIS technologies use digital information, for which various digitized data creation methods are used. The most common method of data creation is digitization, where a hard copy map or survey plan is transferred into a digital medium through the use of a computer- aided design (CAD) program, and geo- referencing capabilities.
Other quotes to answer “What is GIS? A geographic information system manipulates data about these points. Like what you're reading on GIS Lounge?
With the wide availability of ortho- rectified imagery (both from satellite and aerial sources), heads- up digitizing is becoming the main avenue through which geographic data is extracted. Heads- up digitizing involves the tracing of geographic data directly on top of the aerial imagery instead of through the traditional method of tracing the geographic form on a separate digitizing tablet.[edit]Relating information from different sources. If you could relate information about the rainfall of your state to aerial photographs of your county, you might be able to tell which wetlands dry up at certain times of the year. A GIS, which can use information from many different sources in many different forms, can help with such analyses. The primary requirement for the source data consists of knowing the locations for the variables. Location may be annotated by x, y, and z coordinates of longitude, latitude, and elevation, or by other geocode systems like ZIP Codes or by highway mile markers.
Any variable that can be located spatially can be fed into a GIS. Several computer databases that can be directly entered into a GIS are being produced by government agencies and non- government organizations[citation needed]. Different kinds of data in map form can be entered into a GIS. A GIS can also convert existing digital information, which may not yet be in map form, into forms it can recognize and use.
Geographic information system Windows 8 Freeware Downloads - Free Windows 8 geographic information system Downloads - Windows 8 Downloads - Free Windows8 Download. A geographic information system or geographical information system (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present all types of. Integrating Geographic Information System in a K-12 classroom. A geographic information system (GIS), also known as a geographical information system, captures, stores, analyzes, manages, and presents data that refers to or is. The National Historical Geographic Information System (NHGIS) provides, free of charge, aggregate census data and GIS-compatible boundary files for the United States.
Open source software. The development of open source GIS software has—in terms of software history—a long tradition with the appearance of a first system in 1978. Geographic information system Software - Free Download geographic information system - Top 4 Download - Top4Download.com offers free software downloads for Windows. Geographic information system technology is used in all 50 state health departments, most local departments and most ministries of health worldwide, Kinkade said.
Geographic Information System (application) (GIS) A computer system for capturing, storing, checking, integrating, manipulating, analysing and displaying data related.
For example, digital satellite images generated through remote sensing can be analyzed to produce a map- like layer of digital information about vegetative covers. Another fairly developed resource for naming GIS objects is the Getty Thesaurus of Geographic Names (GTGN), which is a structured vocabulary containing around 1,0. Likewise, census or hydrologic tabular data can be converted to map- like form, serving as layers of thematic information in a GIS.[edit]Data representation.
GIS data represents real world objects (roads, land use, elevation) with digital data. Real world objects can be divided into two abstractions: discrete objects (a house) and continuous fields (rain fall amount or elevation). There are two broad methods used to store data in a GIS for both abstractions: Raster and Vector. A raster data type is, in essence, any type of digital image represented in grids. Anyone who is familiar with digital photography will recognize the pixel as the smallest individual unit of an image.
A combination of these pixels will create an image, distinct from the commonly used scalable vector graphics which are the basis of the vector model. While a digital image is concerned with the output as representation of reality, in a photograph or art transferred to computer, the raster data type will reflect an abstraction of reality. Aerial photos are one commonly used form of raster data, with only one purpose, to display a detailed image on a map or for the purposes of digitization. Other raster data sets will contain information regarding elevation, a DEM, or reflectance of a particular wavelength of light, LANDSAT. Digital elevation model, map (image), and vector data.
Raster data type consists of rows and columns of cells, with each cell storing a single value. Raster data can be images (raster images) with each pixel (or cell) containing a color value. Additional values recorded for each cell may be a discrete value, such as land use, a continuous value, such as temperature, or a null value if no data is available. While a raster cell stores a single value, it can be extended by using raster bands to represent RGB (red, green, blue) colors, colormaps (a mapping between a thematic code and RGB value), or an extended attribute table with one row for each unique cell value. The resolution of the raster data set is its cell width in ground units.