Assessment on island ecological vulnerability to urbanization: A tale of Chongming Island, China

The twenty first century has witnessed an emerging research interest in island urbanization, which will set further pressure on island ecological vulnerability (IEV), especially in those islands with a fixed link to the mainland. In this contribution, the IEV of eighteen towns and townships in Chongming Island is assessed based on an "exposure (E)-sensitivity (S)-adaptive capacity (A)" framework and by means of the entropy weight method for determination of the weight of fifteen indicators. The assessment results show that: (1) An index system consisting of 1 objective, 3 sub-objectives, 8 elements, and 15 indicators can be established and tested to reflect the IEV to island urbanization; (2) The overall ecological vulnerability of Chongming Island to urbanization is at a rather low level, with only three out of eighteen towns and townships at a moderate high and high IEV level, while the spatial distribution of IEV surrounds Chengqiao, the seat of the district government, and radiates in a fan-shaped manner; (3) Chengqiao inevitably leads among the towns and townships in its IEV value, and its westward urbanization has adversely affected the IEV of adjacent towns Xinhe and Jianshe. (4) Chenjia's moderate low level of IEV comes as a surprise to the authors, due largely to its proximity to Shanghai. Our proposed E-S-A framework and assessment model could be rationally applied to similar islands with fixed links to the mainland nationally and internationally, which is the major contribution of our study.