Evaluation of five landscape-level metrics for measuring the effects of urbanization on landscape structure: the case of Tucson, Arizona, USA

Landscape-level metrics can be used to measure changes in landscape structure over time. Four landscape-level metrics and rank-size distributions were used to describe changes in landscape structure caused by urbanization in a portion of the Tucson, Arizona metropolitan area between 1984 and 1998. This analysis describes what each metric conveys regarding how urbanization affects landscape structure. It also compares the efficacy of rank-size distributions with the other metrics. Results indicate all five metrics provided information about a specific aspect of landscape structure including patch size, shape, or dispersion. Results indicate that rank-size distributions and their scaling exponents are useful because they provide information not available from the other metrics. Rank-size distributions describe the patch-size scaling properties of specific land-cover types, the relative effect of large and small patches on the distribution of patch sizes, the magnitude of change in patch size, where patch sizes differ from what is expected by the regression model, and the range of patch sizes displaying fractal patterns.