2.3.2 Canals Example 5

Location of Example: 150°8'43" East, 28°27'8" South
Distinctive Characteristics:
  • Drains/Canals can be differentiated from natural watercourses by their linear structure.
  • Natural Watercourses can be differentiated from Drain/Canals by remnant vegetation adjacent to stream path.
  • Drains/Canals can be differentiated from Roads as they do not provide connectivity to the existing road network.
  • If the Drain/Canal is completely dry it will appear lighter, similar to the surrounding soil and vegetation. The the edges will often appear much lighter, due to the excavated soil from construction.
  • Drains generally start at a water source and can end at a Reservoir, Dam or Sea.
  • Drains follow the topography of the land whereas roads may traverse hills and valleys.
  • The use of multispectral imagery band combinations can aid in the interpretation and differentiation of water.
Regional Considerations:
  • In areas where there is irrigated crop farming Canals/Drains appear as regular structured networks which show a water flow hierarchy diminishing from source. They are often aligned with paddocks and have access tracks or roads running parallel to them.
Figure: Representation of Canals in association with surrounding features.

Figure: Orthophotography 60cm RGB=123 Figure: SPOT RGB=123

Topic contact: mapfeedback@ga.gov.au Last updated: January 20, 2012