Coastal SEES Collaborative Research: Morphologic, Socioeconomic, and Engineering Sustainability of Massively Anthropic Coastal Deltas: the Compelling Case of the Huanghe Delta

由于其非凡的自然资源和生态系统服务，河流三角洲海岸线容纳了全世界数亿人。然而，社会对三角洲景观的可持续性是不确定的，这是由于重大的人类影响，包括：1)河道筑坝和堤防导致沉积物--任何三角洲系统维持生命的资源--的减少，2)扰乱了河流三角洲海岸线内和沿线的自然沉积物扩散和沉积模式，3)地下水和化石燃料开采导致低洼三角洲景观加速下沉，以及4)海平面上升，有淹没三角洲景观的危险。该项目的首要目标是通过将考察三角洲增长的物理方面的科学与社会经济决策相结合来评估河流三角洲的可持续性。这项研究将为脆弱的三角洲资源的可持续利用提供指导，同时促进保护社会和基础设施免受河流洪水、海洋风暴和海平面上升等灾害影响的最佳工程实践。其他更广泛的影响包括为沿海可持续发展跨学科领域培训未来学者，创建一个基于互联网的界面，以提高全球公民对沿海可持续发展的认识，并为休斯顿和洛杉矶代表性不足的群体开发教学单元和补充讲习班，供关于沿海科学和可持续发展的高中课程使用。该项目是美国国家科学基金会海岸科学、工程和可持续发展教育计划-海岸可持续发展计划的一部分。建设可持续三角洲海岸线的关键资源是泥沙，控制泥沙输送的关键是河道撕裂、河道相对快速的位移和新河道的形成。一个由多个研究人员组成的跨学科研究团队将解决以下问题，这些问题对河流三角洲沿海的可持续性至关重要：在一个高度利用的三角洲上，改变河道路径会产生什么社会经济后果？当前三角洲地区的土地流失缓解战略在长期(数十年至数百年)的时间尺度上是可持续的吗？能否预测未来重大洪灾事件的发生地点？这些问题将以黄河三角洲中国为个案进行研究。黄河三角洲是一个引人注目的地区，因为它是世界上最具活力和高度城市化的沿海景观之一。从黄河三角洲吸取的经验教训将被输出，以评估全球三角洲海岸线的可持续性。该项目将通过将三角洲撕裂的机制、相关的河道-海岸线相互作用、对自然和工程撕裂的社会经济反应以及由此产生的人-自然系统动态耦合起来，建立沿海可持续性的预测模型。美国研究人员将与中国同事合作，为多学科的沿海可持续发展研究创建一个模板，以帮助指导未来的治理和决策，其中整合了人类三角洲动力学、社会目标和不确定性、灾害和土地利用工程、海岸地貌动力学和教育推广。该项目将评估在沉积物供应减少和海平面上升的情况下，是否可以使用工程撕裂来管理大规模人类活动的沿海景观，以最大限度地减少海岸侵蚀。

Owing to their extraordinary natural resources and ecosystem services, river-delta coastlines host hundreds of millions of people worldwide. However, the sustainability of society on delta landscapes is uncertain, due to significant human influences including: 1) reduction of sediment - the life sustaining resource for any delta system - as a result of damming and leveeing of river channels, 2) disrupting natural sediment dispersal and deposition patterns within and along river-delta coastlines, 3) accelerated sinking of low-lying deltaic landscapes due to sub-surface water and fossil fuel extraction, and 4) sea-level rise, which threatens to drown deltaic landscapes. The overarching goal of this project is to evaluate river-delta sustainability by merging science that examines physical aspects of delta growth with socio-economic decisions. This research will provide guidance for the sustainable use of vulnerable delta resources, while promoting best engineering practices that protect society and infrastructure from disasters including river flooding, ocean storms, and sea-level rise. Additional broader impacts include training future scholars for the interdisciplinary field of coastal sustainability, creating an internet-based interface to promote global-citizen awareness in coastal sustainability, and developing teaching modules with complementary workshops intended for high-school courses on coastal science and sustainability for underrepresented groups in Houston and Los Angeles. This project is supported as part of the National Science Foundation's Coastal Science, Engineering, and Education for Sustainability program - Coastal SEES.The crucial resource in building sustainable deltaic coastlines is sediment, and the key control on sediment delivery is river channel avulsions, relatively rapid displacements of river channels and the formation of new river channels. A multi-investigator, cross disciplinary team of researchers will address the following questions of fundamental importance to river-delta coastal sustainability: What are the socioeconomic consequences of altering river channel pathways on a highly utilized delta? Are current delta land loss mitigation strategies sustainable over long-range (decades to centuries) timescales? Can the location of significant future flooding events be predicted? These questions will be addressed using the Huanghe (Yellow River) delta, China as a case study. The Huanghe delta is a compelling region because it is one of the most dynamic and heavily urbanized coastal landscapes in the world. Lessons learned from the Huanghe delta will be exportable to evaluate the sustainability of delta coastlines worldwide. This project will build predictive models for coastal sustainability by bringing together the mechanics of avulsion on deltas, associated channel-shoreline interaction, socio-economic response to natural and engineered avulsions, and the resulting coupled human-natural system dynamics. U.S. researchers in cooperation with Chinese colleagues will create a template for multi-disciplinary coastal sustainability research to help guide future governance and decision making that integrates human-delta dynamics, societal objectives and uncertainty, hazard and land use engineering, coastal morphodynamics, and educational outreach. This project will evaluate whether massively anthropic coastal landscapes can be managed using engineered avulsions to minimize coastal erosion in the face of reduced sediment supply and rising sea level.