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Analysis of Geographic Data


Difficulties of Geographic Analysis
  • Plenty of data.
  • Spatial relationships are important but difficult to measure.
  • Inherent uncertainty due to scale.
  • any data sources.
  • Difficult to make data sources compatible.
  • Difficult mathematics.
  • Quantity vs. Quality Questions.
  • Multiple objectives.
  • GIS can address some (but not all) of these difficulties.

Network Analysis
Network models are based on interconnecting logical components, of which the most important are:
  1. "Nodes" define start, end, and intersections
  2. "Chains" are line features joining nodes
  3. "Links" join together points making up a chain.
This network can be analyzed using GIS.A simple and most apparent network analysis applications are:
  • Street network analysis,
  • Traffic flow modelling,
  • Telephone cable networking,
  • Pipelines etc.
The other obvious applications would be service centre locations based on travel distance.

Basic forms of network analysis simply extract information from a network. More complex analysis, process information in the network model to derive new information. One example of this is the classic shortest-path between two points. The vector mode is more suited to network analysis than the raster model.

A Road Network


Image

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