Data Input





urban image



The urban extent for the start year, or seed, is used to initialize the model and is the basis for the CA driven urban growth. For calibration, the earliest urban year is used as the seed, and subsequent urban layers, or control years, are used to measure several statistical best fit values. For this reason, at least four urban layers are needed for calibration: one for initialization and three additional for a least-squares calculation.

The definition of "urban extent" is up to the creators of the data set. The model simply requires a binary classification of urban/nonurban. Methods used in the past include digitizing city maps and aerial photographs, thresholding remotely sensed images or block densities from census data.

Pixel value range: 0 = nonurban
0 < n < 256 = urban


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