Spatiotemporal changes of landscape pattern in response to urbanization

The combined method of urban gradient analysis and landscape metrics in analyzing the changes of landscape pattern has been widely applied since its introduction by Luck and Wu (2002). In order to address the temporal dynamics of landscape change, this study integrated transect analysis with temporal trend analysis and specifically discussed how changes of residential pattern are related to forms of urban growth. Using Dane County, Wisconsin, USA as an example, a 60 km transect passing through the City of Madison was set up to represent a continuum of rural-urban-rural landscapes. Changes of landscape pattern from 1968 to 2000 were analyzed by FRAGSTATS with four metrics—percentage of landscape (PLAND), Shannon's evenness index (SHEI), patch density (PD), and mean patch size (MPS). Findings from metric analyses revealed that the degree of land-use diversity and landscape fragmentation is positively related to the degree of urbanization. Specifically, at the class-level, residential land-use type shows the strongest positive relationship to the degree of urbanization in all of the class-level metrics adopted. Changes in residential land-use pattern were further analyzed with the number of housing units. The analyses revealed that there are different patterns of residential development along the transect in the study area—with the core urban area expanding outward in a contiguous manner while the rural areas have scattered development. This study demonstrated the additional insights into landscape change by integrating the spatial and the temporal perspectives and by targeting the forms of residential developments.