Interactions of Flexible Aquatic Vegetation with Turbulent Flows in Rivers: field experiments and mathematical modeling with implications for transport and retention of organic matter and nutrients in fluvial ecosystems

水生植物是河流生态系统的重要组成部分。它们为许多水生物种提供栖息地和有机碳，并对水流、地貌动力学和养分运输产生直接影响。虽然最近在描述植物在实验室水流中的影响的理论方面取得了进展，但由于对柔性植物与自然溪流中湍流之间相互作用的有限了解，它们在河流中的应用仍然存在问题。这项研究旨在通过野外实验研究来量化和模拟植被-水流相互作用的机制。研究将探索非均匀(斑块)分布的柔性水生植被对水流结构的影响。此外，我们还将对植被马赛克中的颗粒物传输进行量化。现场实验将以实验室研究为指导，通过理论分析和数值模拟来完成。研究结果将通过解析建模的方式得到推广，而通过数值模拟的完成，将获得更广阔的参数空间和对流动物理的更深层次的理解。拟议的研究项目是跨学科的和国际化的，结合了国际地质调查局在进行复杂的实地实验方面的专业知识，与麻省理工学院在精细的实验室研究和理论分析方面的专业知识，以及与用户界面在高级数值模拟方法方面的专业知识。

Aquatic plants are an important component of fluvial ecosystems. They provide habitat and organic carbon for many aquatic species and also have direct effects on flow, morphodynamics, and nutrient transport. While there have been recent advances in theories that describe the effects of plants in laboratory flows, their application in rivers is still problematic due to limited knowledge of the mutual interactions between flexible plants and turbulence in natural streams. The proposed research is aimed at quantifying and modeling the mechanisms of vegetation-flow interactions by carrying out field experimental studies. The studies will explore the impact of flexible aquatic vegetation with a non-uniform (patchy) distribution on the flow structure. In addition we will quantify particulate matter transport in vegetation mosaics. The field experiments will be guided by laboratory study and accomplished with theoretical analysis and numerical modeling. The results of the study will be generalized by means of analytical modeling, while the wider parameter space and deeper understanding of flow physics will be gained through the completion of numerical simulations. The proposed research project is interdisciplinary and international, combining the expertise of IGB in carrying complex field experiments with that of MIT in elaborate laboratory studies and theoretical analysis, and with UI in advanced methods of numerical simulations.