The role of in-channel aquatic vegetation on hyporheic exchange

河道内水生植被对潜流交换的作用

• 批准号: 1559348
• 负责人: Daniele Tonina
• 金额: $ 55.8万
• 依托单位: Regents of the University of Idaho
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1559348&HistoricalAwards=false
• 关键词: role; channel; aquatic; vegetation; hyporheic

In-channel vegetation, IAV, is ubiquitous in watercourse as plants or algae. It provides many vital ecological and hydromorphological functions and is becoming a major tool in river restoration. Research on IAV has chiefly focused on sediment transport and flow resistance, while its role in inducing hyporheic exchange has been neglected. Hyporheic exchange is the main process connecting streams with streambeds by moving in-stream water in and out of the streambed sediment through the hyporheic zone, HZ, which serves as an interface between surface and ground waters. The HZ promotes important biological and chemical processes, which affect the quality of both stream and streambed waters. Consequently, modeling hyporheic fluxes due to IAV will provide key information for river restoration practices in which planting has been advocated, a $1B per year industry. Additionally, predictions of hyporheic exchange and processes are essential to quantify solute transport and transformation along streams and rivers. Thus the goal of this research is to model hyporheic flow due to IAV. This will provide a fundamental and predictive understanding of the processes that control hyporheic exchange due to flow and IAV interaction. It will advance knowledge on hyporheic flow field near the rhizosphere, the region of sediment directly influenced by root secretions and associated soil microorganisms and the ability to model solute, nutrient, contaminant, and pathogen transport along stream networks by including the effect of IAV. The models developed in this project will be used to predict hyporheic processes in streams with vegetation and will be incorporated into basin-scale transport models of solute and nutrients. A new transformative after school program will be developed to introduce 5th-6th grade students to STEM disciplines through hands-on activities and lessons with a mobile educational flume. In addition undergraduate and graduate Civil Engineering students will be trained. The scientific goal of this project is to mechanistically understand, quantify, and model the effects of IAV on hyporheic exchange as a function of IAV density, patch size, and patch distribution under different flow conditions. IAVs will be considered with three schematizations: 1) interaction between flow and an individual emergent and submerged vegetation stem, 2) interaction between flow and one single submerged vegetation patch, and 3) interaction between flow and multiple submerged vegetation patches. This will be addressed with novel tracer test flume experiments, coupling Matching Index Reflectometry, Particle Image Velocimetry, and analytical and numerical modeling, and by testing three specific hypotheses: hyporheic exchange has an inverse U-shaped (increases to a maximum and then decreases with increasing value of the independent variable) relationship with: (1) IAV density; (2) IAV patch size; and (3) the percent of streambed covered by multiple dense IAV patches.

河道内植被 IAV 作为植物或藻类在水道中无处不在。它提供了许多重要的生态和水文形态功能，并正在成为河流恢复的主要工具。 IAV的研究主要集中在沉积物输送和流动阻力方面，而忽略了其诱导潜流交换的作用。潜流交换是连接溪流与河床的主要过程，通过潜流区 (HZ) 将河流内的水移入和移出河床沉积物，HZ 是地表水和地下水之间的界面。 HZ 促进重要的生物和化学过程，影响溪流和河床水质。因此，对 IAV 引起的潜流通量进行建模将为河流恢复实践提供关键信息，在河流恢复实践中提倡种植，这是一个每年 10 亿美元的行业。此外，预测潜流交换和过程对于量化溶质沿溪流和河流的迁移和转化至关重要。因此，本研究的目标是模拟 IAV 引起的微流。这将为控制由于流动和 IAV 相互作用引起的微流交换的过程提供基本的和预测性的理解。它将增进对根际附近的潜流流场、直接受根分泌物和相关土壤微生物影响的沉积物区域的了解，以及通过考虑 IAV 的影响来模拟沿河流网络的溶质、养分、污染物和病原体运输的能力。该项目开发的模型将用于预测有植被的溪流中的潜流过程，并将被纳入盆地规模的溶质和养分传输模型中。我们将开发一项新的变革性课后计划，通过移动教育水槽的实践活动和课程，向 5 至 6 年级的学生介绍 STEM 学科。此外，土木工程专业的本科生和研究生也将接受培训。该项目的科学目标是机械地理解、量化和模拟 IAV 对潜流交换的影响，作为不同流量条件下 IAV 密度、斑块大小和斑块分布的函数。 IAV 将考虑三种模式：1）水流与单个挺水和淹没植被茎之间的相互作用，2）水流与单个水下植被斑块之间的相互作用，3）水流与多个水下植被斑块之间的相互作用。这将通过新颖的示踪剂测试水槽实验、耦合匹配指数反射测量、粒子图像测速以及分析和数值建模来解决，并通过测试三个具体假设：潜流交换与以下各项具有倒 U 形关系（增加到最大值，然后随着自变量值的增加而减少）：（1）IAV 密度； (2)IAV补丁大小； (3) 被多个密集 IAV 斑块覆盖的河床百分比。

项目成果

Experimentally Mapping Water Surface Elevation, Velocity, and Pressure Fields of an Open Channel Flow Around a Stalk

• DOI: 10.1029/2021gl096835
• 发表时间: 2022-03
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: J. Moreto;W. J. Reeder;R. Budwig;D. Tonina;Xiaofeng Liu

Seeing through porous media: An experimental study for unveiling interstitial flows

• DOI: 10.1002/hyp.11425
• 发表时间: 2018-01
• 期刊: Hydrological Processes
• 影响因子: 3.2
• 作者: S. Rubol;D. Tonina;L. Vincent;Jill A. Sohm;W. Basham;R. Budwig;P. Savalia;E. Kanso;D. Capone;K. Nealson

A Biologically Friendly, Low‐Cost, and Scalable Method to Map Permeable Media Architecture and Interstitial Flow

一种生物友好、低成本且可扩展的方法来绘制可渗透介质结构和间隙流

• DOI: 10.1029/2020gl090462
• 发表时间: 2021
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Hilliard, Brandon;Reeder, William J.;Skifton, Richard S.;Budwig, Ralph;Basham, William;Tonina, Daniele
• 通讯作者: Tonina, Daniele

Particle Seeded Grains to Identify Highly Irregular Solid Boundaries and Simplify PIV Measurements

颗粒播种谷物可识别高度不规则的固体边界并简化 PIV 测量

• DOI: 10.3389/feart.2019.00195
• 发表时间: 2019
• 期刊: Frontiers in Earth Science
• 影响因子: 2.9
• 作者: Basham, William;Budwig, Ralph;Tonina, Daniele
• 通讯作者: Tonina, Daniele