GEOGRAPHICAL INFORMATION SYSTEM (GIS)

Maps are used as the languages of simple geography. Significance of map making is recognised long ago. Surveyors went around the land and prepared various maps. Data required for locating and calculating extent of a place/region is known spatial data.

Human activities and Physical properties and related to a place/region are stored in the form of charts, tables and texts. This information is known attribute data.

Referring to plans or map and then to attribute data stored in hard copies such as books is time consuming updating and managing the data is hard.

This problem is conquers by combining spatial data and attribute data of the location by suitable data base management in computers. The information (spatial data) of location is digitised from available maps and stored in computers. Data structure used is either vector data or raster data format for this. In raster data structures pickcells are connected with the spatial information, whereas in vector data structure coordinates are associated with each region and sub-regions. Over the spatial data attribute data is stored and overlaid. The user can access the attribute data of any place just by clicking over the spatial data of that place once this geographical information system is developed. The user can used the information for further analysis, planning or for the management. For instance, if land records of a village are developed as GIS data, the user may click the state map to pick up the district map and afterwards access taluka map. Then he shall access it to pick up the village map. Then land record of that village can be got and property map of any owner can be verified and printed. All this can be achieved in a very short time from any suitable place.

As lot of data for GIS is from remote sensing, remote sensing and GIS go hand in hand. Remote sensing requires GIS for data analysis. Some areas of GIS application are following:

1. drainage systems   

2. streams and river basins management

3. lakes                       

4. canals

5. roads                     

6. railways

7. land records           

8. layout of residential areas

9. location of market, , cultural , industrial and other utilities

10. land use of different crops etc.

In planning infrastructural development activities the above information helps such as, rail routes, dams, planning roads, canals, tunnels, etc. It is helpful in taking steps to verify hazards of soil erosion and environmental pollution. In future Monitoring of crop pattern & condition is helpful in taking essential action to the challenges.