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INTRODUCTION TO GEOGRAPHIC INFORMATION SYSTEMS

  • - V Madhava Rao, P Kesava Rao and R R Hermon
    1. INTRODUCTION

    With the fast growing trends in computer technology information systems and virtual world to obtain data about the physical and cultural worlds, and to use these data to do research or to solve practical problems. The current digital and analog electronic device facilitates the inventory of resources and the rapid execution of arithmetic or logical operations. These Information Systems are undergoing much improvement and they are able to create, manipulate, store and use spatial data much faster and at rapid rate as compared to conventional methods.

    Information System, a collective of data and tools for working with those data, contains data in analog form or digital form about the phenomena in the real world. Our Perception of the world through selection, generalization and synthesis give us information and the representations of this information that is, the data constitute a model of those phenomena. So the collection of data, the data base is a physical repository of varied views of the real world representing our knowledge at one point in time. Information is derived from the individual data elements in a database, the information directly apparent i.e. information is produced from data by our thought processes, institution or what ever based on our knowledge. Therefore in a data base context the terms data, information and knowledge are differentiated. It can be summarized that the data is very important and added value as we progress from data to information, to knowledge. The data, which has many origins and forms, may be any of the following:

    1. Real, for example the terrain conditions etc.
    2. Captured, i.e. recorded digital data from remote sensing satellites or Arial photographs of any area.
    3. Interpreted, i.e. landuse from remote sensing data.
    4. Encoded i.e. recordings of rain-gauge data, depth of well data etc.
    5. Structured or organized such as tables about conditions of particular watershed.
    2. DEVELOPMENTS IN THE FIELD OF INFORMATION SYSTEMS

    Geographic Information Management Technology encompasses many fields including Computer Science, Cartography, Information Management, Telecommunications, Geodesy, Photogrammetry and Remote Sensing and is flavored with it’s applications of engineering, environmental analysis, land use planning, natural resource development, infrastructure management, and many others. Geographic Information Management Technology has almost as many names and acronyms as uses.

    One common name is Geographic Information System (GIS). Another is automated mapping/facilities management (AM/FM). Although GIS has recently became more widely accepted as a generic term for the technology, the term Geographic Information System was first published in a 1965 Northwestern University discussion paper by Michal Dacy and Dvane Marble. Key terms associated with geographic information management technology include:

    1. Automated Mapping (A.M.)
    2. Computer Assisted or Computer Aided Mapping (CAM)
    3. Computer Aided Drafting (CAD)
    4. Computer Aided Drafting and Design (CADD)
    5. Geographic Information System
    6. Automated Mapping/ Facility Management (AM/FM)
    7. Geoprocessing and Network Analysis
    8. Land information System
    9. Multipurpose Cadastre

    All these terminology’s are often used interchangeably even though they denote different capabilities and concepts (Figure 1).

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    Figure 1: Geographic Information Technology
    3. HISTORY OF GIS

    The GIS history dates back 1960 where computer based GIS have been used and their manual procedures were in life 100 years earlier or so. The initial developments originated in North America with the organizations such as US Bureau of the Census, The US Geological Survey and The Harvard Laboratory for computer graphics and Environmental Systems Research Institute (commercial). Canadian Geographic Information Systems (CGIS) in Canada, Natural Experimental Research Center (NREC), Department of Environment (DOE) in notable organizations in U.K. involved in early developments. Even the other parts of the world are noticed but they have taken place in recent past. In India the major developments have happened for the last one-decade with significant contribution coming from Department of Space emphasizing the GIS applications for Natural Resources Management. Recently the commercial organizations in India have realized the importance of GIS for many applications like infrastructure development, facility management, business/market applications etc.