Contribution short abstract:

Coastal wetlands on the edge of the megacity represent a key area in terms of the resilient adaptation strategy. From a historical perspective, this study revealed land use changes and driving factors in association with wetlands, with a special reference to eastern Chongming Island, Shanghai City.

Contribution long abstract:

Coastal urban areas are faced with risks induced by global warming and sea level rise,which puts pressure on regional sustainable development. Coastal wetlands on the edge of the megacity represent a vulnerable ecosystem and a key area in terms of the resilient adaptation strategy. However, the interrelationship between the development of these wetlands and the megacity’s adaptation practice has not been sufficiently analyzed. From a historical perspective, we attempt in this study to reveal long-term land use stages and driving factors in association with urban marginal wetlands, with a special reference to eastern Chongming Island, Shanghai. On such a basis, the future adaptation strategy of the megacity is evaluated. The analytical results show that this island has witnessed three periods of time for wetland utilization: traditional land use for salt production, fishery and agriculture before 1950s, industrialization with rapid reclamation in the middle and late 20th century, and the land use pattern orientated toward wetland ecosystem protection after the beginning of the 21st century. The driving forces include sediment budget on the coast, wetland morphodynamic processes, sea level rise, population growth, and resource management policy changes. Furthermore, facing future climate change, there are different options of adaptation. It may not be suitable for coastal cities with a large population to take the retreat option. It will be suitable for coastal communities to adhere to the location, if solutions to the problems of flooding risk, coastal erosion, and the maintenance of coastal facilities can be found.