Urban expansion in Centre County, Pennsylvania: spatial dynamics and landscape transformations.

摘要

Sprawling urban development is a major driving force of landscape fragmentation and loss of agricultural land. Despite this understanding, science has yet to realize a coherent suite of methods to analyze all circumstances of sprawl. Consequently, this paper contributes to this realization by combining three methods to address sprawl in a small US metropolitan area - Centre County, Pennsylvania: cross-tabulation to identify systematic non-random land use transitions; logistic regression to determine explanatory variables of urban land use location resulting from these transitions; and the CLUE-S regional modeling framework to project future urban land use patterns in the county. The results demonstrate the versatility of the methodology because of its ability to detect land use change despite the large proportion of the landscape that remained uncharged during the two periods under consideration, and because of its ability to distinguish systematic non-random land use transitions from random ones. The strength of the methodology is further demonstrated by its capability to allocate land use change according to change in land use location as well as to net change in land use quantity. The methodology identified soil and topography as the primary explanatory drivers of urban land use location in Centre County. Although the model is able to simulate urban land use location at the county level, it is less able to simulate these locations at the sub-county level, thereby suggesting that the explanatory variables for urban land location are not fully captured at this scale. Overall, the methodology for sprawl analyses presented in the study is robust and adds to the tools available to decision makers for assessing sprawl dynamics.