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

Lead Research Organisation: National Oceanography Centre
Department Name: Science and Technology

Abstract

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.

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 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.

Publications

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Project Reference Relationship Related To Start End Award Value
EP/R024537/1 01/02/2018 31/10/2019 £211,109
EP/R024537/2 Transfer EP/R024537/1 01/11/2019 31/03/2021 £88,530
 
Description The delta model has been set up in FVCOM and validated.
Some intermediate results have been obtained.
Key findings are that (i) the mean sea level has seasonal variability (ii) tidal amplitude changes due to projected mean sea level (iii) complex interactions between tides, surges, waves and current occur.
Exploitation Route It is still early days in the research but we expect that our results will help identify optimum conditions for mangrove restoration, to provide nature-based coastal defence
Sectors Environment

URL https://projects.noc.ac.uk/ancode/
 
Title Data presented in the paper: A Novel Instrument for Bed Dynamics Observation Supports: Machine Learning Applications in Mangrove Biogeomorphic Processes 
Description Short-term bed level dynamics on the intertidal flats plays a critical role in long-term coastal wetland dynamics. High-frequency observation techniques are crucial for better understanding of intertidal biogeomorphic evolutions. Here, we introduce an innovative instrument for bed dynamics observation, i.e. LSED-sensor (Laster based Surface Elevation Dynamics sensor). LSED-sensors inherit the merits of the previously-introduced optical SED-sensors as it enables continuous long-term monitoring with relatively low cost of labor and acquisition. By adapting Laster-ranging technique, LSED-sensors avoid touching the measuring object (i.e. bed surface) and they do not rely on daylights, as it is for the optical SED-sensors. Furthermore, the new LSED-sensors are equipped with a real-time data transmission function, enabling creating automatic observation networks covering multiple (remote) sites. During a 21-days field survey in a mangrove wetland, good agreement (R2=0.7) has been obtained between the automatic LSED-sensor measurement and an accurate ground-truth measurement method, i.e. Sedimentation Erosion Bars. The obtained LSED-sensor data was subsequently used to develop machine learning predictors, which revealed the main drivers of the accumulative and daily bed level changes. We expect that the LSED-sensors can further support machine learning applications to extract new knowledge on coastal biogeomorphic processes. 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
URL https://data.4tu.nl/articles/Data_presented_in_the_paper_A_Novel_Instrument_for_Bed_Dynamics_Observa...
 
Title FVCOM-wave model of the Pearl River Delta 
Description A coupled hydrodynamic-wave model of the Pearl River Delta using an unstructured mesh has been implemented, based on the FVCOM model system. 
Type Of Material Computer model/algorithm 
Year Produced 2019 
Provided To Others? No  
Impact This model has been used in several peer-reviewed publications, to study the effect of intereactions between tides, storm surges and waves and the effect of sea level rise due to climate change. 
 
Description Collaboration with Dutch and Chinese partners on this project 
Organisation ABP Marine Environmental Research Ltd
Country United Kingdom 
Sector Private 
PI Contribution We are carrying out numerical hydrodynamic and wave modelling for the Pearl River Delta and South China Sea under present and future conditions considering sea level rise and typhoons
Collaborator Contribution The Dutch partners are investigating the behaviour of mangroves and oyster reefs in providing nature-based coastal protection
Impact Conference presentations Outreach activities
Start Year 2018
 
Description Collaboration with Dutch and Chinese partners on this project 
Organisation Dutch Research Council
Department Royal Netherlands Institute for Sea Research
Country Netherlands 
Sector Academic/University 
PI Contribution We are carrying out numerical hydrodynamic and wave modelling for the Pearl River Delta and South China Sea under present and future conditions considering sea level rise and typhoons
Collaborator Contribution The Dutch partners are investigating the behaviour of mangroves and oyster reefs in providing nature-based coastal protection
Impact Conference presentations Outreach activities
Start Year 2018
 
Description Collaboration with Dutch and Chinese partners on this project 
Organisation Ministry of Ecology and Environment, The People’s Republic of China
Department Satellite Environment Center
Country China 
Sector Public 
PI Contribution We are carrying out numerical hydrodynamic and wave modelling for the Pearl River Delta and South China Sea under present and future conditions considering sea level rise and typhoons
Collaborator Contribution The Dutch partners are investigating the behaviour of mangroves and oyster reefs in providing nature-based coastal protection
Impact Conference presentations Outreach activities
Start Year 2018
 
Description Collaboration with Dutch and Chinese partners on this project 
Organisation Sun Yat-Sen University
Country China 
Sector Academic/University 
PI Contribution We are carrying out numerical hydrodynamic and wave modelling for the Pearl River Delta and South China Sea under present and future conditions considering sea level rise and typhoons
Collaborator Contribution The Dutch partners are investigating the behaviour of mangroves and oyster reefs in providing nature-based coastal protection
Impact Conference presentations Outreach activities
Start Year 2018
 
Description Collaboration with Dutch and Chinese partners on this project 
Organisation Utrecht University
Country Netherlands 
Sector Academic/University 
PI Contribution We are carrying out numerical hydrodynamic and wave modelling for the Pearl River Delta and South China Sea under present and future conditions considering sea level rise and typhoons
Collaborator Contribution The Dutch partners are investigating the behaviour of mangroves and oyster reefs in providing nature-based coastal protection
Impact Conference presentations Outreach activities
Start Year 2018
 
Description Invited participation in BlueTech week discussion on COP26 'Nature-based solutions' 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact This was a round-table discussion at BlueTech week in Nov 2020 in San Diego to inform ploicymakes about the issues on 'Nature-based solutions' in preparation for COP26
Year(s) Of Engagement Activity 2020
URL https://www.bluetechclusters.org/btca-member-events/2020/11/16/the-12th-annual-bluetech-week