Characterizing the spatiotemporal evolutions and impact of rapid urbanization on island sustainable development

Islands, which deliver a diversity of fundamental services, are subject to increasing pressure from urbanization and human activities, particularly in developing countries. This paper integrates socioeconomic drivers, topographic variables, and policy guidance to characterize the spatiotemporal dynamics of urban expansion between 1980 and 2013 in the Zhoushan islands, China. Our results indicate that the Zhoushan islands experienced remarkable urban expansion and economic prosperity over that period, with a clear acceleration since 2000. The increase in built initially occurred in urban cores and then spread to peri-ocean areas over the last decade. These hotspots were the outcomes of co-occurrence of ports, harbors, and coastal industries or tourism establishments, suggesting a considerable disparity among islands with different functions. We further quantified the socioeconomic drivers of urban expansion using multivariable regression. Generally, the major drivers were secondary and tertiary industry growth because of the effect of governmental interventions and changing economic conditions on coastal industries and tourism development. Cross-sea bridges also served to accelerate island development, while population had a lesser impact. Compared with other successful cases worldwide, extensive development and inefficient land use are prevalent in the Zhoushan islands. Available land has become more rare on the islands and reclamation from the ocean has been increasingly applied to expand land area for construction. There are still large gaps in island sustainable development, suggesting that intensive and reasonable land-use planning should be prioritized over exploring the potential for urban development. The results of this study can inform ecological management, and provide a scientific case for urban development and contributed to sustainability of islands and coastal regions.