Introduction to GIS

GIS is a computer based integrated database management system that stores a large volume of spatial data along with its attribute or non spatial data which are captured, stored, retrieved, processed and analyzed to provide answers to queries of a geographical nature as and when required.

The fundamental key of GIS is that, the association of Geographic features present on earth� surface, which can be the geo-referenced one with a database related to it. The term "Geo-referencing "refers to providing accurate location of a point or area in the space in terms of true earth co-ordinate system and "Database� is simply a collection of raw facts which are stored in a structural manner having relationship with each other. In a nutshell, Spatial data can be described as "where thing are� and attribute data are "what things are�.

The GIS history dates back 1960 where computer based GIS began to be used. The initial developments originated in North America, where Canada was pioneer in the development of GIS. Initially the Canadian Geographic Information System (CGIS) in Canada, US Bureau of Census, and the US Geological Survey, the Harvard Laboratory for computer graphics and Environs, Natural Experimental Research Centre (NREC), Department of Environments of UK were involved in early developments. In India the major development happened from the last one decade where in its earlier phase, the technique was used for Natural Resource management only, but now India has realized the importance of GIs for many applications like infrastructure development, facility management, Business/market applications etc.

GIS technology Integrates common database operations such as query and statistical analysis with the unique visualization and the geographic analysis benefits offered by maps. These abilities distinguish GIS from other information systems and make it valuable to a wide range of public and private enterprises for explaining events, predicting outcomes and planning strategies.