Geographic Information System (GIS) is a computer based information system used to digitally represent and analyse the geographic features present on the Earth’ surface and the events (non-spatial attributes linked to the geography under study) that taking place on it. The meaning to represent digitally is to convert analog (smooth line) into a digital form.
“Every object present on the Earth can be geo-referenced”, is the fundamental key of associating any database to GIS. Here, term ‘database’ is a collection of information about things and their relationship to each other, and ‘geo-referencing’ refers to the location of a layer or coverage in space defined by the co-ordinate referencing system.
Work on GIS began in late 1950s, but first GIS software came only in late 1970s from the lab of the ESRI. Canada was the pioneer in the development of GIS as a result of innovations dating back to early 1960s. Much of the credit for the early development of GIS goes to Roger Tomilson. Evolution of GIS has transformed and revolutionized the ways in which planners, engineers, managers etc. conduct the database management and analysis.
Some Interesting Links :
1. What is GIS ?
A complete compilation of information on GIS
2. GIS guide to Good Practice
A brief introduction to GIS and Archaeology
3. An Introduction to GIS in Real Estate
Gil Castle’s final draft of the real estate column appearing in Real Estate Issues, August 1995
4. A Brief Introduction to GIS Technology
Enhancing Community Capacity to use Spatial Information
A GIS is an information system designed to work with data referenced by spatial / geographical coordinates. In other words, GIS is both a database system with specific capabilities for spatially referenced data as well as a set of operations for working with the data. It may also be considered as a higher order map.
GIS technology integrates common database operations such as query and statistical analysis with the unique visualization and 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. (ESRI)
A Geographic Information System is a computer based system which is used to digitally reproduce and analyse the feature present on earth surface and the events that take place on it. In the light of the fact that almost 70% of the data has geographical reference as it’s denominator, it becomes imperative to underline the importance of a system which can represent the given data geographically.
A typical GIS can be understood by the help of various definitions given below:-
- A geographic information system (GIS) is a computer-based tool for mapping and analyzing things that exist and events that happen on Earth
- Burrough in 1986 defined GIS as, “Set of tools for collecting, storing, retrieving at will, transforming and displaying spatial data from the real world for a particular set of purposes”
- Arnoff in 1989 defines GIS as, “a computer based system that provides four sets of capabilities to handle geo-referenced data :
- data input
- data management (data storage and retrieval)
- manipulation and analysis
- data output. “
Hence GIS is looked upon as a tool to assist in decision-making and management of attributes that needs to be analysed spatially.