What is GIS – Introduction, Definition and Important Terms

In this article we will understand various basic concepts of GIS. You will know what is GIS, Definition of GIs and various important terms (GIS terminology) related to GIS etc.

What is GIS?

Full form of GIS is Geographic Information System. It is some what similar to a regular data base management system with slightly different capabilities. GIS is capable of processing Geographic data for producing geographic information.

Definition of GIS:

GIS can be defined as a computer based database management system which is used for capturing, storing, manipulating, analyzing, retrieving and displaying geographic data.

GIS system converts geographic data into geographic information by making use of its processing capabilities. The data which is input into GIS goes through various phases of transformation before becoming information.

GIS is often regarded as computer tool or a piece of software with a wide range of capabilities to process geographic data. There exist many GIS packages (software tools) both in public domain (open source) and private domain (proprietary). Some of the popular GIS packages are as follows.

Open Source and Free: QGIS, GRASS, ILWIS etc.

Proprietary or Commercial: ArcGIS, Map Info, ERDAS Imagine, ENVI etc.

 GIS Applications in Real World:

Though GIS is used mainly for map making purpose, depending on the user and context the map making and handling capabilities of GIS extends to a greater extent. Some of the popular areas where GIS is used widely are given below.

  • GIS can be used for preparation of Maps.
  • GIS has great importance in solving site selection problems such as landfill sites, wind mill sites, air port sites etc.
  • Watershed delineation can be done with help of GIS.
  • Preparation of Digital Elevation Model and Contour maps can be done using GIS.
  • Runoff studies can be performed.
  • GIS is widely used in Urban planning studies also.
  • GIS is useful in studying, understanding and solving various transportation related problems such as road network planning, shortest path detection, proximity analysis etc.

Apart from the above applications GIS is also used by business people for making profitable decisions, Government and revenue department people for tax realization and dissemination of information to the public through web platforms etc.

GIS Terminology – Important Terms:

Spatial Data: Any data with spatial reference can be termed as spatial data. Often a mere location without any detail is also considered as spatial data. However, even if details are comprehensive without spatial reference (location detail) data cannot be considered as spatial data.

Read Also: Characteristics of Geographic Data

Vector: Spatial data (or any data) requires a data model for storage. Vector is a GIS data model which is useful storing spatial data. In vector data model, data is represented and stored in the form of points, lines and polygons.

Raster: Raster is a GIS data model which is useful for storing spatial data. In raster data model, data is stored in the form of pixels.

Read Also: Vector Data Model, Raster Data Model

Attribute: Attributes are nothing but characteristics. Attributes are stored in the form of a table in GIS. In other words, attributes describes various information related to data. For example, for a road attributes could be road length, road width, no of lanes, road name, road type etc.

>>> Laboratory tutorial: Learn How to add attribute data in ArcGIS Software

Digitization: Digitization is a data input technique used in GIS. It converts analog data into digital data. It produces vector files as the output.

Shape files: Shape files are vector type files used in GIS software for handling spatial data. These shapefiles have .shp as the extension. ‘.shp’ file extension is the native file format used for vector files in popular GIS software ArcGIS.

Buffer: Buffer is a zone created around a feature of interest (such as road, building etc.) with a specific radius.

The above are some of the important terms related to GIS. You may comment below in case if you want me to update this article with new terms and content.

Add a Comment

Your email address will not be published. Required fields are marked *