Newton Fund: Applying nature-based coastal defence to the world's largest urban area - from science to practice

Project Summary:

Nature-based coastal defence solutions have increasingly been recognized as more sustainable alternatives to conventional hard engineering approaches against climate change. These include using wetlands, mangroves, coral and oyster reefs as a buffer zone, which can attenuate waves and, in a regime of moderate sea level rise, the sediment trapping in such zones can keep pace with sea level. Wetlands and mangroves are regions in which more salt-tolerant species exist, which can protect freshwater species behind them. Nature-based defences have been deployed in the USA, Netherlands and UK and also in some parts of China, with varying degrees of success. In deltas undergoing fast urbanisation, applying nature-based solutions can lead to competition for space with other land uses, e.g.
land-reclamation. For optimised management, the question of how much space is required by nature-based solutions must be addressed. However, our current knowledge of the size-dependent defence-value and resilience of different ecosystems is insufficient. Additionally, we lack full understanding of the methods needed for ecosystem creation for coastal defence, as previous restoration efforts have suffered low success rates.

The current proposal aims to develop process-based understanding and predictive models of ecosystem size requirements and how to create ecosystems for coastal defence, using the world's largest urban area, the Pearl River Delta (PRD) in China, as a model system. Delta-scale mangrove area monitoring and hydrodynamic modelling will be conducted to study recent wetland area changes and estimate the optimisation of ecosystem spaces for defence, under contrasting scenarios of climate change and land-reclamation. This large-scaled study will also provide underpinning boundary conditions for local-scale experiments and modelling. A set of experiments using novel instruments will be conducted to improve our insights into the processes influencing mangrove resilience and propagation. Innovative measures of using dredged materials and oyster reefs to facilitate mangrove establishment will also be tested experimentally. Local-scale models will incorporate the new experimental knowledge to predict mangrove bio-geomorphic dynamics and provide guidelines for management.

The developed models and knowledge will be directly applied in the design of a pilot eco-dike project due to be constructed, in collaboration with our project partners. We will consider how to address resilient urban planning and management, in terms of combining spatial planning and disaster management by optimising land use, institutions and mechanisms for more sustainable urbanisation, exploring eco-dynamic design options to provide opportunities for nature as part of the urban development processes.

Summary of the UK applicants' contribution to the project:

The UK applicants will lead Work Task 1: Wetland area monitoring/hydrodynamic modelling. This work task will provide an over-view of the bio-physical conditions, including the morphological and land-use aspects of the PRD and its regional setting, for the present day, and under future climate projections of sea level and storms.

The UK team will implement a high resolution unstructured-grid model (FVCOM) for the Pearl River Delta (PRD) for hydrodynamics, waves and sediment transport which will provide the interface between the larger scale atmospheric and oceanic boundary conditions and the smaller-scale process studies and ecosystem modelling to be carried out by our Dutch and Chinese partners. This model, together with regional sea level projections, will be used to provide quantitative scenarios for the local area ecological modelling.

This proposal aims to advance the sustainable economic development and well-being of the millions of people living in China's populous and highly urbanised deltas, particularly the Pearl River Delta (PRD). This is the most threatened region in the world in terms of number of people subject to the impacts of sea level rise. Nature-based defences are a way of protecting the coast and simultaneously retaining threatened ecosystems, and are increasingly recognised as more sustainable alternatives to conventional hard engineering approaches to protect the coastline against climate change. Improved coastal defences will provide social and economic benefits to these coastal populations.
However, in deltas undergoing rapid urbanisation, such as the PRD, applying nature-based solutions can lead to competition for space with other land uses, e.g. land-reclamation. For optimized management, the question of how much space is required by nature-based solutions is important and not fully understood. Additionally, we are lacking insights into ecosystem creation for coastal defence, since previous restoration efforts have suffered a low success rate. The project aims to find practical solutions to some of these questions about design and implementation of nature-based coastal defence, by developing process-based understanding and predictive models of ecosystem size requirements and how to create ecosystems for coastal defence. This knowledge will benefit coastal and urban planners.
The developed models and knowledge will be directly applied in the design of a 23 km-long innovative eco-dike to be implemented in 2018-2021. For example, we will be interacting with partners at Guangdong Hydropower Planning & Design Institute, who are in frequent contact with local stakeholders. Within the research project, we will investigate the area and location of land reclamation, mangrove and oyster reefs, which are required to provide the needed coastal protection, and how they can best be established, under realistic future scenarios of storms and sea level rise in this region. This will directly benefit local stakeholders and planners.
The SYSU-NIOZ-NOC research teams also have consortium partners at Deltares, Wageningen Marine Research, LISCO, ABPmer and CH2M, who all have an interest in such nature-based defences. So, by having their input in the research, we can ensure that the work will be relevant for coastal planners in this area and be taken up by them.
Impact Activities
1. Project meetings: a project meeting including consortium partners will be convened every half year. Four of these project meetings will be convened in China, including the kick-off and the final meetings, and the other half of the meetings will rotate between UK and NL.
2. Stakeholder workshops: during the 8 project meetings, we will always reserve half a day to meet with project partners, local stakeholders and end-users, in order to give updates of the project and receive feedbacks. Three workshops tailored for stakeholders and end-users will be co-organised in the final year, one in each of the three countries, to reach a large audience for knowledge dissemination and utilisation. A joint scientific workshop will also be co-organised to invite external scientists for knowledge exchange.
3. Project website: this will be set up to share news and results, and finally briefing notes and policy guidelines
4. Training: Students and post-docs will gain useful experience during the project and be able to use these skills in future projects.