1. Data base set-up

1.1. Creation of Geographic Temporal Data Base
publication references

1.1.1. Aquisition
Final formatting requirements are described on the input data page. The spatial data required for model input may be compiled in a geographic information system (GIS). Types of regional attribute data include urban extent, transportation, land use/cover, areas where urbanization cannot occur, areas resistant to urban development, and topography. All data must be registered to the same geographic projection.

1.1.2. Transformation
The model accepts input data in GIF image format, therefore all data must be rasterized in a grid format. All attribute grids must have the same extent and resolution so that the row and column count is consistent across all grids. (In ArcInfo: the commands LINEGRID or POLYGRID may be used to transform vector data to raster, and GRIDIMAGE will transform grids to several image formats. An image software such as xv or Photoshop may be used to convert to GIF image format.)

1.1.3. Brute force calibration and data resampling
Due to the extensive computational requirements of calibrating the model, a brute force method has been used to derive parameter values. This method involves calibrating the model to the data in steps, sequentially narrowing the range of coefficient values and increasing the data resolution*. We generally try to accomplish this in three steps: coarse, fine and final.

coarse
In the initial coarse phase of calibration, the entire range (0 - 100) of the five coefficients is explored using large increments (e.g.; for each coefficient, value = {0, 25, 50, 75, 100}), and the resolution of the data is 1/4 of its full size. For example, if a data set's full resolution is 200x200, for coarse calibration all images would be resampled to 50x50.

fine
Using the best fit values found in the control_stats.log file produced in the coarse calibration phase, the range of possible coefficient values is narrowed. Ideally, the ranges will be narrowed so that increments of 5 - 10 may be used while still only using about 5-6 values per coefficient (e.g.; for a coefficient, value = {25, 30, 35, 40, 45, 50}). These new ranges are then applied to data that has been resampled to 1/2 of its full resolution. For example, if a data set's full resolution is 200x200, for fine calibration all images would be resampled to 100x100.

final
Using the best fit values found in the control_stats.log file produced in the fine calibration phase, the range of possible coefficient values is narrowed. Ideally, the ranges will be narrowed so that increments of 1 - 3 may be used while still only using about 5-6 values per coefficient (e.g.; for a coefficient, value = {4, 6, 8, 10, 12}). These new ranges are then applied to the full resolution data.

* How the data is resampled is up to the user. It may be done entirely in the raster environment. However, if source data are in a vector format (e.g.; transportation), the resolution of the grid may be selected at the time of transformation in to raster and might be perferable to resampling a grid.

1.2. Naming Convention

The model expects greyscale, GIF image files with the file name format as described below. The file names must be listed in the scenario file. The attribute names must read as indicated below (urban, roads, landuse, excluded, slope or hillshade). The date must be a four digit integer. If the file names deviate from this format they will not be read in by the model.

    <  >  = user selected fields
   [<  >] = optional fields

Urban data GIFs:
  format:  <location>.urban.<date>.[<user info>].gif

Examples:
URBAN_DATA= demo200.urban.1930.gif
URBAN_DATA= demo200.urban.1950.gif
URBAN_DATA= demo200.urban.1970.gif
URBAN_DATA= demo200.urban.1990.gif

Road data GIFs:
  format:  <location>.roads.<date>.[<user info>].gif

Examples:
ROAD_DATA= demo200.roads.1930.gif
ROAD_DATA= demo200.roads.1950.gif
ROAD_DATA= demo200.roads.1970.gif
ROAD_DATA= demo200.roads.1990.gif

Land use data GIFs:
  format:  <location>.landuse.<date>.[<user info>].gif

Example:
LANDUSE_DATA= demo200.landuse.1930.gif
LANDUSE_DATA= demo200.landuse.1990.gif

Excluded data GIF
  format::  <location>.excluded.[<user info>].gif

Example:
EXCLUDED_DATA= demo200.excluded.gif

Slope data GIF
format :  <location>.slope.[<user info>].gif

Example:
SLOPE_DATA= demo200.slope.gif

Background data GIF
format :   <location>.hillshade.[<user info>].gif

Example:
BACKGROUND_DATA= demo200.hillshade.gif