Time-series color-infrared aerial photos (1994e2003, 2006) and Quickbird images (2004e2005) were re-sampled to 2.5 m and georeferenced to the local geographic coordinates. These aerial photos and images were imported into the ArcGIS 10.2 platform. Visual interpretation by skilled experts was conducted to obtain the specific information of four urban land types, including residential land, industrial land, public facilities and transportation land. In order to provide an overview of the megacity growth, I displayed three years (first, middle and last) of urban land use maps.
Urban growth can be divided into three categories according to the sprawl types: edge, infilling and leapfrogging ( Jiao, Mao, & Liu, 2015; Li, Li, & Wu, 2013; Liu et al., 2010). The Landscape Growth Index (LGI; Eq. (1)), formulated by Liu et al. (2010)