Toward a sustainable urban expansion: A case study of Zhuhai, China

Literature on urban expansion has grown rapidly, yet researchers are still far from a full spectrum of comprehensive understanding. Debates about the spatiotemporal patterns of urban expansion have risen alongside a lack of a comprehensive framework engaging environmental dimension in analyzing urban expansion efficiency. Moreover, cross-boundary development as a significant driving force of border city expansion has long been neglected in previous studies. By applying remote sensing and Geographic Information System (GIS) methods to the case of Zhuhai, this study attempts to add empirical evidence for enriching the discussion on spatiotemporal patterns, urban expansion efficiency, and the driving forces of urban expansion. Indices including annual urban growth rate, urban expansion intensity index, local Moran's I, and landscape expansion index are adopted to measure urban expansion and its evolving patterns. A set of urban expansion efficiency indices under a three-dimensional framework is proposed and applied in empirical calculation. The impacts of cross-boundary development are considered in analyzing the mechanism behind. Zhuhai's urban expansion was modest and fluctuated across the study period from 1980 to 2015, evolving from a double-center city to a multi-center city. Edge expansion dominated nearly all the phases, while the fast expansion periods coincided with the proportional increase of outlying expansion. Mixed performance in the three dimensions of urban expansion efficiency and significant correlation between the economic and environmental dimensions were identified. Accessibility factors were found to be the primary factors of the urban expansion of Zhuhai, followed by natural environmental factors and socioeconomic factors. Among these factors, cross-boundary factor played a substantial role. Current findings may generate implications for policymakers and contribute to a more comprehensive understanding of urban expansion. (C) 2019 Elsevier Ltd. All rights reserved.