CAREER: Modeling 19th century estuaries to address 21st century problems

职业：建模 19 世纪河口以解决 21 世纪问题

• 批准号: 1455350
• 负责人: Stefan Talke
• 金额: $ 50万
• 依托单位: Portland State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2020-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1455350&HistoricalAwards=false
• 关键词: CAREER; Modeling; 19th; century; estuaries

Addressing 21st century problems such as coastal flooding, sea-level rise, and salinity intrusion requires understanding both long-term trends and spatial patterns in tides and water level. Historical observations and retrospective modeling of historical conditions are needed to fully evaluate and interpret the cause of long term trends. This study will investigate the long-term dynamics of tides and transport in the Columbia River Estuary using verifiable data to elucidate system sensitivities. Well-known, idealized insights into tidal dynamics and scalar transport will be tested in a complex environment, to test how altered local topography, wetland area, and depth have produced physical changes. The dynamical questions raised may have implications for the past development and future trajectory of estuaries globally. The project will train a graduate student and engage High School teachers and underrepresented students.This study leverages ongoing efforts to digitize 19th century data and a recently developed numerical model of the historic Columbia River Estuary. By pioneering new ways of calibrating historical models and evaluating spatio-temporal trends via historical/modern model comparison, this project will lay the groundwork for similar, future research in other strongly-altered estuaries. Using time series of water temperature back to 1854, new ground will be broken by simulating historical water temperatures. Because water temperature, like salinity, is mixed along the river/ocean continuum, it will be used to calibrate and verify salinity intrusion in both historical and modern models. This approach circumvents the lack of historical salinity data, increases model fidelity, and allows for process-based studies to determine the historical factors which have altered water levels, habitat inundation, baroclinic circulation, and transport. The primary hypotheses are: (a) Direct anthropogenic alterations, rather than climate induced changes to river flow or sea level, have dominated changes to estuary functioning since the 19th century; (b) water temperature and salinity variability was much larger in the past than today but changes in flow and channel depth have increased salinity intrusion; and (c) changes in tide propagation in the tidal river will be reflected in altered flood wave propagation: flood waves will move faster, and disperse less, than in the past.

解决21世纪的问题，例如沿海洪水，海平面上升和盐度入侵需要了解潮汐和水位的长期趋势和空间模式。 需要对历史条件的历史观察和回顾性建模，以充分评估和解释长期趋势的原因。这项研究将使用可验证的数据来阐明系统敏感性，研究哥伦比亚河河口潮汐和运输的长期动态。对潮汐动力学和标量运输的众所周知，理想化的见解将在复杂的环境中进行测试，以测试局部地形，湿地区域和深度改变的如何产生身体变化。提出的动态问题可能对全球河口的过去发展和未来轨迹具有影响。该项目将培训一名研究生，并吸引高中教师和代表性不足的学生。这项研究利用了持续的努力来数字化19世纪的数据，以及最近开发的历史悠久的哥伦比亚河河口的数值模型。通过开创校准历史模型并通过历史/现代模型比较评估时空趋势的新方法，该项目将为其他强烈改变的河口中的类似，未来的研究奠定基础。使用时间序列的水温回到1854年，通过模拟历史水温将破坏新的地面。由于水温（如盐度）沿着河流/海洋连续体混合，因此将用于校准和验证历史和现代模型中的盐度侵入。这种方法规避了缺乏历史盐度数据，增加了模型的保真度，并允许基于过程的研究确定改变水位，栖息地淹没，斜压循环和运输的历史因素。主要的假设是：（a）直接的人为改变，而不是气候引起的河流或海平面变化，自19世纪以来河口功能的变化主导了； （b）过去的水温和盐度变异性要比今天大得多，但是流量和通道深度的变化增加了盐度侵入； （c）潮汐河中潮汐传播的变化将反映在变化的洪水传播中：洪水的移动速度比过去更快，分散的速度要少。