Wednesday, September 23, 2015

Cost and Path analysis using GIS

A cost path analysis enables one to calculate the various costs associated with traveling from one location to another. Costs in this sense can have a number of variations such as:

  • actual monetary expenditure
  • time and effort required to complete the movement from one place to another
  • costs of construction and
  • environmental costs, such as damage to habitats and ecosystems.
In cost path analysis, these various types of cost may be combined into one comprehensive grid. The path of least cost from one point to another may then be determined on this "cost surface". Routes with high associated costs are less favorable than routes with a lower cost associated with it.

Map layers or criteria which may be useful in creating a cost surface include:

  1. Elevation
  2. Land cover
  3. Land ownership (private, public, etc.)
  4. Slope
  5. Bodies of water
A cost surface, or cost grid, is a raster grid in which the value in each cell is the cost that a particular activity or object would be in that cell. It can also be an indexed value based on costliness. Costs could be measured monetarily or in other ways such as amount of time. A cost surface includes the cost of reaching certain cells from one or more source cells.