Geographic information

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Geographic information (also known as spatial or geospatial data) consist of descriptions of the characteristics of geographic phenomena (natural or man-made). These characteristics may include location, attributes, relationships with other phenomena, and how these characteristics change over time. Geographic information science is therefore the study of the collection, storage, integration, management, retrieval, display, analysis, and modeling of geographic information.[1]

Representing Geographic Information

Objects

Geographic information can appear in a variety of forms, often dependent on the nature of the phenomena they describe. Discrete objects, such as buildings or roads, are typically described by a set of measured dimensions and consist of one or more shapes. Continuous phenomena or masses that are not discrete, such as a vegetation area, are represented by interpreted or estimated dimensions. For example, two ecologists could differ in what each considers the extent of an area of dense vegetation. This would result in two maps that display the same phenomenon (dense vegetation) with different dimensions.

Fields

Geographic information also includes characteristics or properties of an object. These properties are called fields. Most fields are two-dimensional scalar fields, meaning they have a location and a value. Fields can range in type, from properties of natural phenomena (i.e. temperature) to calculated attributes (i.e. population density).

Displaying Geographic Information

Geographic information can be displayed or presented using multiple methods of delivery. The most common medium for displaying geographic information employs the discipline of cartography or mapmaking. Other mediums include tables, graphs, textual descriptions, databases, and digital deployment using the web.

The development of technologies such as remote sensing, Global Positioning System (GPS), and geographic information systems (GIS) have greatly enhanced the process of gathering, analyzing, and presenting geographic information.

References

  • Spatial data, Esri Support Online - GIS Dictionary (Spatial Data)
  • Chang, K. (2010). Introduction to Geographic Information Systems. New York: McGraw-Hill.
  • Campbell, J. (2001). Map Use and Analysis. New York: McGraw-Hill

Notes

  1. Wilson and Fotheringham: The Handbook of Geographic Information Science, page 1. Blackwell Publishing Ltd, 2008