Characterizing Urban growth of Nanjing, China, by using multi-stage remote sensing images and landscape metrics

Remote sensing technique has advantages in exploring the spatiotemporal trends of urbanization compared with traditional socioeconomic indicators (e.g. population growth, employment shifts, etc.). Details in urban change and growth can be effectively identified using multi-temporal images of remote sensing by multi-scales analysis approaches at the metropolitan, city or district level. In this study, the temporal and spatial characteristics of urban growth of Nanjing, China from 1988 to 2007 were investigated by using multi-stage remote sensing images and landscape metrics. The results show that land use changes exhibit distinctive spatial differences from the urban zone to the suburban districts. The total urban expansion was faster in the period from 2000 to 2007 than in the period from 1988 to 2000. Urban built-up area expanded due to the increased population and rapid economic development and government policy led to the rapid growth towards the Jiangning district area. The variety of landscape metrics results from land use changes indicate the general trend and detail spatial pattern of urbanization in each administrative district during the study period. This study also confirms that the combination of multistage remote sensing images analysis with landscape metrics is an effective way in characterizing the complex spatial patterns of urbanization in Nanjing well.