Visual image interpretation of land use - a GI research perspective

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Visual image interpretation of land use - a GI
research perspective

• Dr Nigel Trodd
• Coventry University

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Land use human employment of the land

• Almost all of the worlds lands are now used and
  managed (Richards 1990).
• Human actions rather than natural forces are the
  source of most contemporary change in the states
  and flows of the biosphere. Understanding these
  actions and the social forces that drive them is
  thus of crucial importance for understanding,
  modeling and predicting global environmental
  change and for managing and responding to such
  change (Turner Meyer, 1994).

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Land use - data sources

• Land use maps have been completed for many
  specific areas of the world. These efforts were
  based on various data sources and are not
  generally compatible with each other. A
  consistent, hierarchical classification system is
  ... to be encouraged (WMO 1997).
• An objective system that can be updated annually
  may be possible using remote-sensing of land
  cover change (perhaps combined with agriculture
  and forestry production statistics,
  socio-economic spatial data such as population
  and transportation). Landsat (TM) is one of the
  most appropriate data streams for land use
  monitoring. While it is still a research topic on
  how to use this data to produce a land use
  product, it is important that this data stream
  continues to be archived and kept accessible
  (WMO 1997).

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Land use - research agenda

• What information is needed?
• Frequency of measurement Once every 5 years.
• Spatial resolution 5 m - 1 km depending on the
  spatial heterogeneity of land use at least 30 m
  for many regions.
• Accuracy/precision required TBD.
• What R T D is needed?
• Develop regionally-specific relationships between
  land cover and land use
• Define the lowest acceptable spatial resolution
• Develop reliable procedures of inferring land use
  from land cover, on a regional basis.

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Land use / land cover physical state of the land

• single land use type may correspond to a single
  land cover class
• e.g. pastoralism to unimproved grassland
• single land cover class may support multiple uses
• e.g. forest used for timber, hunting/gathering,
  fuelwood, recreation, wildlife preservation, soil
  protection
• single land use may occupy multiple classes
• e.g. mixed farming uses cultivated land, improved
  pasture, settlements and woodland

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Visual image interpretation
tonetextureshadow
associationshape
patternsizesite
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Information products

• Feature extraction

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Information products

• Integrated terrain unit

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Information products

• Land systems

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Anderson - Level 1
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Anderson - Level 2
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Anderson - Level 2
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Mapping land use

• identify target land use categories
• define the properties of each land use category
  in terms of land cover characteristics
• specify technique for extracting land cover
  characteristics using elements of visual image
  interpretation
• apply technique
• invert relationship between land cover and land
  use
• generate land use information