CAREER: Dynamic Water Transport Timescales: Quantifying Hydrodynamic Responses to Perturbations Across Time and Space in a River Delta

地表水在沿海环境中的移动受海洋和陆地过程的控制，这产生了随时间和空间变化的复杂的水循环模式。水在环境中流动所需的时间通常被用作水质和生态系统健康的重要评估指标。在河流三角洲，这是复杂的存在深，快速移动的水在渠道连接到缓慢，浅移动的水在植被湿地。重要的是要了解河流三角洲的水运输时间如何随着时间的推移而演变，因为在利用自然三角洲的土地建设过程的海岸恢复相当大的兴趣。本项目通过在路易斯安那州沿海地区的实地考察和对不断增长的河流三角洲的水运动进行计算机模拟来调查这些问题。教育计划建立在这些主题的培训大学生使用创新的沿海水文实地测量，沿海水文研究纳入本科和研究生课程，并从事K-8学生与示范，指导研究项目和实地考察。 河流三角洲是一个高度动态的生态系统，水文复杂，具有重要的社会和环境意义。这项研究解决了水文学的迫切需要，了解水文过程是如何演变的非静态生态系统，利用数值模拟，现场观测和图论。该项目将发展动态水运时间尺度的概念，并建立一个框架，量化三角洲形态和水动力学的变化如何影响水运时间。基本问题将被解决有关的影响，几十年的形态动力学变化对短期水文输运在河流三角洲，地表水响应内部和外部扰动跨越时间和空间，以及三角洲通道网络结构和水运输时间之间的联系。该奖项由水文科学计划和地球科学部的教育人力资源计划共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Surface water movement through coastal environments is controlled by both marine and terrestrial processes, which yields complicated patterns of water circulation that vary through time and space. The time it takes for water to move through an environment is often used as an important estimator of water quality and ecosystem health. In river deltas, this is complicated by the presence of deep, fast-moving water in channels that is connected to slow, shallow moving water in vegetated wetlands. It is important to understand how water transport times in river deltas evolve over time because of the considerable interest in using natural deltaic land-building processes for coastal restoration. This project investigates these issues using field work in coastal Louisiana and computer simulations of water movement in growing river deltas. An educational plan builds on these themes by training university students using innovative field measurements for coastal hydrology, integrating coastal hydrology research into undergraduate and graduate coursework, and engaging K-8 students with demonstrations, guided research projects, and field trips. River deltas are highly dynamic ecosystems with complicated hydrology that are of significant societal and environmental importance. This research addresses an urgent need in hydrology to understand how hydrological processes evolve in non-stationary ecosystems using numerical modeling, field observations, and graph theory. The project will develop the concept of Dynamic Water Transport Timescales and establish a framework for quantifying how changes to delta morphology and hydrodynamics impact water transport time. Fundamental questions will be addressed concerning the impacts of multi-decadal morphodynamic change on short-term hydrological transport in river deltas, the surface water responses to internal and external perturbations across time and space, and the links between deltaic channel network structure and water transport times. This award is co-funded by the Hydrologic Sciences program and the Education & Human Resources program in the Division of Earth Sciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.