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

通过沿海环境的地表水运动受海洋和陆地过程的控制，这产生了复杂的水循环模式，这种模式在时间和空间上都有所不同。水通过环境所需的时间通常被用作水质和生态系统健康的重要估计值。在河流三角洲，这是复杂的，因为在与植被覆盖的湿地中缓慢而浅的水流相连的水道中，存在着深而快的水流。重要的是要了解河流三角洲的水运时间是如何随着时间的推移而演变的，因为人们对利用自然三角洲造地过程来恢复海岸很感兴趣。该项目使用路易斯安那州沿海地区的实地工作和不断增长的河流三角洲中的水运动的计算机模拟来调查这些问题。教育计划以这些主题为基础，使用沿海水文学的创新实地测量方法培训大学生，将沿海水文学研究纳入本科生和研究生的课程，并让K-8学生参与示范、有指导的研究项目和实地考察。河流三角洲是高度动态的生态系统，具有复杂的水文学，具有重要的社会和环境意义。这项研究解决了水文学中的一个迫切需要，即利用数值建模、现场观测和图论来了解非静态生态系统中的水文过程是如何演变的。该项目将发展动态水运时间的概念，并建立一个框架，以量化三角洲形态和水动力的变化如何影响水运时间。基本问题包括：多年代际地形动力变化对河流三角洲短期水文输运的影响、地表水对时空内外扰动的响应、三角洲河网结构与输水时间之间的联系。该奖项由地球科学部的水文科学项目和教育与人力资源项目共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.