Wetland Utilization and Adaptation Practice of a Coastal Megacity: A Case Study of Chongming Island, Shanghai, China

Abstract

Coastal urban areas are faced with risks induced by global warming and sea level rise, which puts pressure on regional sustainable development. In particular, land use adjustment is closely related to climate change for a coastal megacity. 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, based on document synthesis and field investigation, 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 1950, industrialization with rapid reclamation during 1950–2001, and the land use pattern orientated toward wetland ecosystem protection after 2002. The driving forces include sediment budget on the coast, wetland morphodynamic processes, sea level rise, population growth, and resource management policy changes. Transformation occurred between the wetland utilization stages in response to the changes of these forces. Furthermore, facing future climate change, there are different options of adaptation, e.g., retreatment and adherence. It may not be suitable for coastal cities with a large population to take the first 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. For eastern Chongming wetlands, as a key experimental area for ecosystem-oriented development in Shanghai, the transformation from the reclamation-oriented utilization toward the protection of wetland ecosystems represents the first step toward the latter option. We suggest that the next steps would be to maintain the ecological niche of the wetlands, to create new approaches to coastal engineering with contributions from the ecosystem, and to provide better ecosystem services.

Multi-scenario simulation of land use dynamics and ecological risk: a case study of the liaohe estuary national wetland reserve using PLUS-Markov and PSR models

“…In the process of land use Frontiers in Environmental Science frontiersin.org change, its ecological effects should be considered and strengthen the self-healing function of the ecosystem, based on the ecological environment capacity and regional resource endowment conditions. For eastern Chongming wetlands, as a key experimental area for ecosystem-oriented development in Shanghai, has transformed from the reclamation-oriented utilization toward the protection of wetland ecosystems to adapt to future development under climate change (Bao and Gao, 2021). Considering the results of this study in Liaohe Estuary wetland, ecological protection policies can effectively reduce ecological risks by promoting sensible land use planning, especially in outer buffer area and experimental area which are more easily influenced by the protection policy.…”

Assessing Coastal Vulnerability and Evaluating the Effectiveness of Natural Habitats in Enhancing Coastal Resilience: A Case Study in Shanghai, China

“…For example, Chongming Dongtan Wetland provides habitats and resources for diverse bird species; Paotaiwan Wetland Forest Park and Binjiang Forest Park, which are on the north coast of the mainland, provide recreational and educational opportunities for local residents [127]. However, a large number of habitats are currently under great stress of loss and degradation due to both natural and anthropogenic factors, including extensive reclamation, pollution, species invasion, coastal erosion, and sea level rise [128,129]. For these reasons, relevant regulations should be formulated to strictly control reclamation projects and waste discharge.…”

Long‐term Spartina alterniflora invasion simplified soil seed bank and regenerated community in a coastal marsh wetland

“…As a sea‐land ecotone, coastal salt marsh wetland with simple structure and weak resistance and stability, is vulnerable to the alien species invasion (Neira et al, 2005). Dongtan as a typical salt marsh wetland locates in the Shanghai Chongming island of eastern China, formed at the estuary by long‐term silting carried by the Yangtze River (Bao & Gao, 2021). Dongtan wetland is usually characterized by simple plant species composition and low density, and there is also a large area of bare beach without vegetation cover (Dai et al, 2013; Wang & Li, 2016).…”