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Part - VI

Information Retrieval: With GIS a location, object, or area on the screen can be pointed and recorded information may be retrieved about it from off-screen files. Using scanned aerial photographs as a visual guide, GIS easily answers about the geology or hydrology of the area or even about how close a swamp is to the end of a street. This type of analysis allows one to draw conclusions about the swamp's environmental sensitivity.

Topological Modeling: A GIS can recognize and analyze the spatial relationships among mapped phenomena. Conditions of adjacency, containment, and proximity can be determined with a GIS.

Data Capture: Information loading into the system involves identifying the objects on the map, their absolute location on the Earth's surface, and their spatial relationships. Software tools that automatically extract features from satellite images or aerial photographs are gradually replacing what has traditionally been a time-consuming capture process. Objects are now identified as "information" part of a GIS.

Data Restructuring: When the digital data are collected and stored in different ways, the two data sources may not be entirely compatible. Therefore, a GIS must be able to convert data from one structure to another. For example, a GIS can be used to convert a satellite image map to a vector structure.

Networks: It is often important to know in which direction the streams flow and which streams empty into other streams. This is done by using a linear network. It allows the computer to determine how the nutrients are transported downstream.

Data Output: A critical component of a GIS is its ability to produce graphics on the screen or on paper to convey the results of analyses to the people who make decisions about resources. Wall maps, Internet-ready maps, interactive maps, and other graphics can be generated, allowing the decision makers to visualize and thereby understand the results of analysis or simulations of potential events.

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* Contributed by -
Saurabh Singh,
MBA Global,
IMT Nagpur.