RAPID: Connecting the historic 2011 Mississippi River flood to marsh sedimentation on the Delta

RAPID：将 2011 年密西西比河历史性洪水与三角洲沼泽沉积联系起来

• 批准号: 1140269
• 负责人: Douglas Jerolmack
• 金额: $ 5万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-15 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1140269&HistoricalAwards=false
• 关键词: RAPID; Connecting; historic; 2011; Mississippi

The project aims to determine the impact of a geologically significant flood event on coastal sedimentation patterns and rates. Determining transport pathways will enable researchers from University of Pennsylvania, University of Mississippi, and the U.S. Geological Survey to connect the dots between river dynamics, coastal dynamics, and marsh maintenance. Two contrasting river plumes will be studied?-that of the Mississippi River itself, which is expected to disperse sediment into the Gulf and not contribute greatly to wetland development because of its narrow, focused jet, and that of the Atchafalaya River, which is expected to spread diffusely across the landscape and be more prone to deposit sediment to nourish wetlands. The research will make use of satellite data, physical sampling, and numerical modeling. Measurement approaches are (1) analysis of satellite data on sea surface temperature, color, and height; (2) collection of sediment samples at the outlet of the Mississippi River using a boat survey with acoustic dopplar, surface sediment samples, and bed grab samples, and (3) measurement of marshland sediment accretion rates once the floodwaters begin to subside. New theory recently developed by two of the PIs for estimating mixing rates and sedimentation patterns in coastal Louisiana resulting from the flood will be captured in a model. The results of the model will be compared with measured plume dynamics off the Mississippi River, and sampled marsh sediments from the shelf bottom and marsh surfaces along the Mississippi and Atchafalaya Rivers, to enhance understanding of how the Mississippi Delta functions as a sediment dispersal system.There is consensus that protecting and expanding coastal marshes is vital for coastal Louisiana but much less agreement on how to do it. Scientific understanding of marsh building needs to be bolstered before it can inform this debate. This project seizes a unique opportunity to examine constrasting modes of sediment dynamics in two plumes from the historic 2011 Mississippi floods, and aims to enhance the scientific basis for delta restoration that will become increasingly important in the years to come.

该项目旨在确定地质上重要的洪水事件对沿海沉积模式和速率的影响。 确定运输途径将使宾夕法尼亚大学，密西西比大学和美国地质调查局的研究人员能够连接河流动力学，沿海动力学和沼泽维护之间的点。 将研究两个对比的河羽？该研究将利用卫星数据，物理采样和数值建模。 测量方法是（1）分析有关海面温度，颜色和高度的卫星数据； （2）使用声音多普拉，表面沉积物样品和床夹样品的船只调查收集了密西西比河出口的沉积物样品，（3）一旦洪水开始消退，沼泽地沉积物的积聚率一旦测量。 最近由两个PI开发的新理论用于估计路易斯安那州沿海地区洪水的混合速率和沉积模式，将在模型中捕获。 该模型的结果将与密西西比河的测得的羽流动态进行比较，并从架子底部和密西西比州和阿查菲拉亚河沿岸的沼泽沉积物中取样，以增强对密西西比三角洲的理解，以增强对沿海地区分散的范围，以至于越来越多的沿海沿海地区的沿海地区，这是如何越来越多的沿海地区。做到。 对沼泽建筑的科学理解必须得到加强，然后才能为这场辩论提供信息。该项目抓住了一个独特的机会，可以在历史悠久的2011年密西西比洪水中检查两种羽毛的沉积物动态模式，并旨在增强三角洲恢复的科学基础，在未来的几年中，这将变得越来越重要。