Spatial and temporal patterns of land cover change in Chengdu, China, 1978-2002

The goal of this work is to monitor urban growth and the drivers of urban expansion in Chengdu, China. Between 1978 and 2002, the municipal population increased from 8 to 10.2 million and GDP grew seven-fold, changes which have had profound impacts on land cover. To address these issues, this research involves two tasks. First, we monitor land cover change using a supervised, multi-date decision tree method that exploits spectral as well as seasonal differences in Landsat imagery. Results indicate that urban areas have increased by more than 350% between 1978 and 2002. Second, we estimate changing urban density by applying spatial landscape metrics and gradient analysis to the map of land cover change. Using a moving window technique, changes in urban pattern are estimated for seven urban-rural corridors. Results show that western corridors exhibit more disaggregate growth, possibly as the result of policies attracting foreign investment. These results have important implications for urban sustainability, resource use, and potential degradation of the environment.