Data Input



SLEUTH requires an input of five types of grayscale gif image files (six if land use is being analyzed). For all layers, 0 is a nonexistent or null value, while 0 < n < 255 is a "live", or existing, value. The model requires all input layers to have a consistent number of rows and columns. For statistical calibration of the model, at least four urban time periods must be used. Also, for purposes of calibration, the roads must be represented in two or more time periods. The model requires two land use layers for deltatron land use modeling. All layers should be checked for agreement; urban areas should not be present locations defined as undevelopable in the excluded layer.

Format standards for all data types

  • grayscale GIF images
  • images are derived from grids in the same projection
  • images are derived from grids of the same map extent
  • images the same resolution (row x column count is consistent)
  • images follow the required naming format

The following images were created as part of a "fictional" data set to demonstrate format, calibration and implementation of SLEUTH. Their purpose is to illustrate the requirements and functions of the model rather than represent processes of a specific city or region. Some images' values on this page have been altered in order to illustrate their content and should not be confused with the actual input image data which may be accessed from our download page.


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