Geographic Information System

A geographic information system (GIS) is a computer system for capturing, storing, querying, analyzing, and displaying geospatial data.

What is geospatial data?
Geospatial data describe both the locations and characteristics of spatial features. To describe a road, for example, we refer to its location (i.e., where it is) and its characteristics (e.g., length, name, speed limit, and direction).

Components of a GIS

Like any IS GIS also has Inputs, Output and Processing in between with the help of Hardware, Software, Networks and People. Lets see what it encompasses.

Hardware. GIS hardware includes computers for data processing, data storage, and input/output; printers and plotters for reports and hard-copy maps; digitizers and scanners for digitization of spatial data; and GPS and  mobile devices for fieldwork.

• Software. GIS software, either commercial or open source, includes programs and applications to be executed by a computer for data management, data analysis, data display, and other tasks.

 GIS consists of the following  elements: geospatial data, data acquisition, data management, data display, data exploration, and data analysis. 

People. GIS professionals define the purpose and objectives for using GIS and interpret and present the results.

 Organization. GIS operations exist within an organizational environment; therefore, they must be integrated into the culture and decision-making processes of the organization

ELEMENTS OF GIS

GIS consists of the following  elements: geospatial data, data acquisition, data management, data display, data exploration, and data analysis.

To locate spatial features on the Earth’s surface, we can use either a geographic or a projected coordinate system. A geographic coordinate system is expressed in longitude and latitude
and a projected coordinate system in x, y coordinates. GIS represents geospatial data as either vector data or raster data


Data acquisition is usually the first step in conducting a GIS project. Data is usually got from public data if public data is not available then we can go for new data using satellite maps.

Data Management  - is usually done through DBMS, and GIS requires huge Databases to store all the data about each coordinate 

Data Display : while creating the data for display in GIS care should be taken that common notations in map making are followed.

Data exploration refers to the activities of visualizing,manipulating, and querying data using maps,
tables, and graphs. A common example is using public database to check if there is any water source nearby or checking for water table before planning any construction work etc.

Data Analysis - A GIS has tools for mapping the terrain in contours, profiles, hill shading, and 3-D views, and for analysing the terrain with  slope, aspect, and surface curvature. Another such tool is Geocoding, it converts postal addresses into point features, and dynamic segmentation locates linearly referenced data on an x-, y-coordinate system. Google Maps +codes is an example of this.

Some of the commercial and opensource GIS is listed below in the table

GIS in India:

So as an Indian you might be intrigued whether we have these kinds of software's in India, our Indian agencies have created many such tools . Some useful tools are listed below

Bhuvan