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

Lead Research Organisation: University of Liverpool
Department Name: Civil Engineering and Industrial Design

Abstract

Project Summary:

Nature-based coastal defence solutions have increasingly been recognized as more sustainable alternatives to conventional engineering approaches against climate change. In deltas undergoing fast urbanization, applying nature-based solutions can lead to space competition with other land uses, e.g. land-reclamations. For optimized management, the question of how much space is required by nature-based solutions is important. However, our current knowledge is insufficient in ecosystem size-dependent defence-value and resilience. Additionally, we are lacking insights into 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, Pearl River Delta, China, as a model system. Delta-scale mangrove area monitoring and hydrodynamic modelling will be conducted to study wetland area changes and optimization of ecosystem spaces for defence, under contrasting scenarios of climate change and land-reclamations.
This large-scaled study will also provide underpinning boundary conditions for local-scaled experiments and modelling. A set of experiments using novel instruments will be conducted to improve our insights on the processes influencing mangrove defence-value and lateral dynamics. Innovative measures of using dredging materials and oyster reefs to facilitate mangrove establishment will also be tested experimentally. Local-scaled models will incorporate the obtained experimental knowledge to predict mangrove biogeomorphic dynamics and provide guidelines for management. The developed models and knowledge will be directly applied in the design of a pilot eco-dike project in collaboration with our partners.

Summary of the UK applicants' proposed contribution to the project:

The focus of the study is on coastal zone management, including management of sediment and nature-based flood defence. 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 Pearl River Delta and its regional setting.

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.

We will also address some objectives within focus area 1 (Resilient urban planning and management) in terms of combining spatial planning and disaster management by optimizing land use, institutions and mechanisms for more sustainable urbanisation, exploring eco-dynamic design options to provide opportunities for nature as part of urban development processes and reducing urban footprints and developing performance evaluation systems to mitigate environmental impacts. We will explore opportunities to apply management decision tools, such as those recently developed in the EPSRC ARCoES project.

Planned Impact

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 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. UK steering group meetings: these will be held once a year during UK project meetings
4. Project website: this will be set up to share news and results, and finally briefing notes and policy guidelines
5. Training: Students and post-docs will gain useful experience during the project and be able to use these skills in future projects.
 
Description The research highlighted the importance of wave-tide-surge interactions in the Pearl River Delta, which is likely to be enhanced by the local accelerating sea level rising. As natural based solution to the potential coastal flooding, vegetation based coastal protection can play an important role and maintain its sustainability through ecological process. The mangrove based protection measure can reduce the water level during stormy condition and delay the timing of High Water along the protected area. The cumulative effects from the mangrove forest can attenuate the water level further upstream of the river branch and reduce the chances of flooding under the extreme conditions as shown in the model simulation.
Exploitation Route The coastal community can benefit from these results by encouraging the development of vegetation based coastal protection measure. The coastal managers can also find relevant information and evidence for development of nature based protection policy. Coastal and estuarine authorities can identify the effective approach in satisfying coastal protection and sustainable development. Coastal engineering practitioners can also develop innovative approach for better protection measure based on these findings.
Sectors Aerospace, Defence and Marine,Construction,Energy,Environment,Transport

 
Description The remote sensing data around the Pearl River Delta on mangrove distribution and evolution since early 2000s have been reported to the Chinese Ministry and the report has been identified as one the key area should be considered at the site in the future.
First Year Of Impact 2021
Sector Agriculture, Food and Drink,Communities and Social Services/Policy,Creative Economy,Environment
Impact Types Economic,Policy & public services

 
Title Coastal typhoon and hydrodynamic model 
Description A new coastal typhoon and hydrodynamic model has been developed based on 3D nearshore coastal model developed previously in the group. The model includes new wave-current interaction algorithm. The wave-tide-surge interactions have been fully accounted for in the model. The new model results for most recent super-typhoon event at the Real River Delta have been summarised and submitted for journal publication. 
Type Of Material Computer model/algorithm 
Year Produced 2020 
Provided To Others? Yes  
Impact The new model suggests a new approach for modelling wave-tide-surge interaction. The fully coupling has been tested and show very good agreement with the observations from the most recent super-typhoon passing the modelling site. The new approch is expected to be picked up by following researcher for futur better prediction of typhoon induced hydrodynamics in the near shore region.