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

项目摘要：基于自然的海防解决方案越来越被认为是对抗气候变化的传统硬工程方法的更可持续的替代方案。这些措施包括利用湿地、红树林、珊瑚和牡蛎礁作为缓冲带，可以减弱海浪，在海平面适度上升的情况下，这些区域的沉积物可以与海平面保持同步。湿地和红树林是耐盐物种较多的地区，可以保护它们背后的淡水物种。基于自然的防御已经在美国、荷兰、英国以及中国的一些地区部署，并取得了不同程度的成功。在快速城市化的三角洲地区，采用基于自然的解决方案可能导致与其他土地用途（如土地复垦）争夺空间。为了优化管理，必须解决基于自然的解决方案需要多少空间的问题。然而，我们目前对不同生态系统的大小依赖防御值和恢复力的了解是不够的。此外，由于以前的恢复工作成功率很低，我们对建立海防生态系统所需的方法缺乏充分的了解。目前的提案旨在以世界上最大的城市地区——中国珠江三角洲（PRD）作为模型系统，开发基于过程的理解和预测生态系统规模需求的模型，以及如何为海防创建生态系统。在气候变化和土地开垦的对比情景下，将进行三角洲尺度的红树林面积监测和水动力建模，以研究近期湿地面积的变化，并估计生态系统防御空间的优化。这项大规模的研究还将为局部规模的实验和建模提供基础边界条件。我们将使用新型仪器进行一系列实验，以提高我们对影响红树林恢复力和繁殖过程的认识。此外，我们亦会试验利用疏浚物料和牡蛎礁促进红树林建设的创新措施。局部尺度模型将结合新的实验知识来预测红树林生物地貌动态，并为管理提供指导。开发的模型和知识将直接应用于即将与我们的项目伙伴合作建设的试点生态堤防项目的设计。我们将考虑如何解决弹性城市规划和管理问题，将空间规划和灾害管理结合起来，通过优化土地利用、机构和机制实现更可持续的城市化，探索生态动态设计方案，为自然提供机会，作为城市发展进程的一部分。英国申请人对项目的贡献总结：英国申请人将领导工作任务1：湿地区域监测/水动力建模。这项工作将提供生物物理条件的概览，包括珠江三角洲的形态和土地利用方面及其区域环境，目前和未来海平面和风暴的气候预测。英国团队将为珠江三角洲（PRD）实施高分辨率非结构网格模型（FVCOM），用于水动力学，波浪和沉积物运输，该模型将提供大尺度大气和海洋边界条件与荷兰和中国合作伙伴进行的小尺度过程研究和生态系统建模之间的界面。该模式连同区域海平面预估，将用于为当地生态模拟提供定量情景。

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.