Coastal SEES Collaborative Research: Multi-scale modeling and observations of landscape dynamics, mass balance, and network connectivity for a sustainable Ganges-Brahmaputra delta

沿海 SEES 合作研究：可持续恒河-雅鲁藏布江三角洲的景观动态、质量平衡和网络连通性的多尺度建模和观测

• 批准号: 1600287
• 负责人: Irina Overeem
• 金额: $ 39.82万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1600287&HistoricalAwards=false
• 关键词: Coastal; SEES; Collaborative; Research; Multi

River deltas around the world are in a state of modest to severe decline, primarily in response to anthropogenic activities such as the damming of rivers, extensive embankment systems, groundwater and gas extraction, and intense land-use pressures. These settings are also among the world's most physically dynamic, being impacted by sea-level rise and subsidence, river flooding, channel erosion, and storms. Such vulnerabilities are further magnified in highly populated delta systems, notably the large mega-deltas that rim Asian coasts in politically sensitive regions from Pakistan to China. These environments suffer not only from having more humans, infrastructure, and livelihoods in peril, but also from the anthropogenic strain that large populations place on physical and ecological support systems. In Bangladesh and West Bengal, India, the Ganges-Brahmaputra-Meghna delta (GBMD) may well be the prime example as the world's largest and most densely populated delta system, hosting 150 million people in an area the size of Louisiana. In this Coastal SEES project, a diverse group of scholars with expertise across several earth-science and engineering disciplines are brought together to answer questions about the fate and future sustainability of the GBMD and its human population. Specifically, is there sufficient river sediment available for the delta to keep pace with sea-level rise to 2100? How does the delta's network of river and tidal channels effectively distribute water and sediment across the region? How are human activities affecting this channel-network system, and what are the subsequent repercussions on human infrastructure? How can research-based knowledge developed in response to these questions help with planning and decision making for a sustainable GBMD and deltas elsewhere? To address these questions, the project combines innovative quantitative tools (numerical modeling, network and connectivity analysis) with new and existing observational data to analyze the coupled human-natural system and long-term sustainability of the GBMD. Specifically, team members will (i) develop a detailed mass balance for delta-wide sediment dispersal; (ii) quantitatively analyze the connectivity of the delta-system network that disperses this sediment; (iii) integrate this knowledge through numerical modeling at local to global scales; (iv) use observational data of landscape and channel dynamics to understand coupled land-sea interactions; (v) evaluate the quality of regional soil and water resources and their links with physical and anthropogenic processes; (vi) assess the impact of these delta dynamics on the human environment and transportation, and finally (vii) disseminate this knowledge through a variety of educational activities and opportunities for students, researchers, and professionals. Team members have collaborated extensively with local entities and universities in Bangladesh; through these contacts the knowledge developed in this project will reach relevant stakeholder communities. Findings are especially urgent to guide large-scale engineering efforts underway to improve the Bangladesh coastal-zone stability. Final products will provide a grounded, integrated, and multidisciplinary view of how the world's largest delta works and its plausible responses to environmental change in the coming century.Some of the international activities in this project are partially supported by a small contribution from the OISE Global Venture Fund.

世界各地的河流三角洲正处于中度至严重的衰退状态，主要是人为活动造成的，如在河流上筑坝、广泛的堤坝系统、地下水和天然气开采以及土地使用的巨大压力。这些环境也是世界上最具物理活力的环境之一，受到海平面上升和下降，河流洪水，河道侵蚀和风暴的影响。这种脆弱性在人口密集的三角洲系统中进一步放大，特别是在从巴基斯坦到中国的政治敏感地区的亚洲海岸周围的大型巨型三角洲。这些环境不仅因为更多的人、基础设施和生计处于危险之中而受到影响，而且还因为大量人口对物理和生态支持系统造成的人为压力而受到影响。在孟加拉国和印度的西孟加拉，恒河-布拉马普特拉-梅克纳三角洲（GBMD）可能是世界上最大和人口最稠密的三角洲系统的主要例子，在路易斯安那州大小的地区容纳了1.5亿人。 在这个沿海SEES项目中，一群拥有多个地球科学和工程学科专业知识的学者聚集在一起，回答有关GBMD及其人口的命运和未来可持续性的问题。具体来说，是否有足够的河流沉积物可供三角洲跟上海平面上升到2100年？三角洲的河流和潮汐通道网络如何有效地将水和沉积物分配到整个地区？人类活动是如何影响这个渠道网络系统的，以及对人类基础设施的后续影响是什么？针对这些问题开发的基于研究的知识如何帮助规划和决策制定可持续的GBMD和其他三角洲？ 为了解决这些问题，该项目将创新的定量工具（数值建模，网络和连通性分析）与新的和现有的观测数据相结合，以分析GBMD的耦合人类-自然系统和长期可持续性。具体而言，小组成员将㈠为整个三角洲的沉积物扩散制定详细的质量平衡; ㈡定量分析分散这种沉积物的三角洲系统网络的连通性; ㈢通过地方到全球尺度的数值建模整合这方面的知识; ㈣利用景观和河道动态的观测数据了解海陆耦合相互作用;（v）评估区域土壤和水资源的质量及其与自然和人为过程的联系;（vi）评估这些三角洲动态对人类环境和交通的影响;最后（vii）通过各种教育活动和机会向学生、研究人员和专业人员传播这一知识。小组成员与孟加拉国的地方实体和大学进行了广泛的合作;通过这些联系，本项目中积累的知识将传播到相关的利益攸关方社区。研究结果对于指导正在进行的改善孟加拉国沿海地区稳定性的大规模工程工作尤为紧迫。最后的成果将提供一个有根据的、综合的、多学科的观点，说明世界上最大的三角洲是如何运作的，以及它对未来世纪环境变化的合理反应。