What is GIS (Geographical Information System)

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GIS (Geographical Information System)


Geographical Information System (GIS) is an integrated tool, capable of mapping, analyzing, manipulating and storing geo-spatial data in order to provide solutions to real world problems (For example: logistics, emergency evacuation, and tax assessment, real estate analysis etc.) and help in planning for the future.

Importance of GIS
GIS is a computer-based tool that allows you to integrate different kinds of geographic information such as satellite images, aerial photographs, digital maps, and global positioning system data (GPS), along with associated tabular database information. 

GIS not only helps you to examine and analyze geographic information at different levels of detail; but also allows the user to perform statistical analysis or spatial analysis. Predictions for the future can also be done using GIS models in the areas of land-use change, urban sprawl, habitat loss, and to predict seismic activity precisely.

Components of GIS

Fig. Diagrammatic View of GIS Components


Hardware : Hardware allows the user to capture, store, process and visualize the geographic information. It consists of technical equipment such as computer/s with good configuration to run the GIS software; enough hard disk space to run the software smoothly; along with input and output devices like digitizers, scanners, printers and plotters etc. 

Software: The GIS software allows you to data input, storage, transformation, analysis and providing desired outputs in the form of maps and reports. The GIS software being used today belong to either of the category –proprietary or open source. 

Proprietary GIS software are ArcGIS, MapInfo, Microstation, Geomedia etc. However, opensource (freely available) GIS software include QGIS, gVSIG, SAGA GIS, GRASSGIS, MapWindow, ILWIS, Open Jump etc.

Data: It is the most important component of the GIS. The data can be captured or collected from various sources For example: maps, field observations, photography, satellite imagery etc. 

GIS data is stored as spatial (geographic data) and non-spatial(tabular) data. Data must be collected from a reliable source and should be accurate record of reality. Geo-Spatial data must be accessible to all users; as data availability is the big concern in most developing countries.

Methods: These include various procedures by which data can be edited, accessed, managed stored, and analyzed to achieve the required output for the particular application and analysis such as change detection analysis.

People: GIS people are the technical persons, who can manage the data, develop procedures, process and analyze geo-spatial data for applying it to real-world problems. Hence, GIS people includes technical specialists, GIS managers, database administrators, programmers, scientists and planners etc.

These above are important components and parts of GIS system. All components are key part of the GIS process. If any single left then it is really difficult to move further. Therefore it is suggested to have complete GIS system including all components to create and analyze geo-spatial data.
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