CAREER: Dynamic water table controls on reactive solute transport near the groundwater-surface water interface

职业：动态地下水位控制地下水-地表水界面附近的反应性溶质输送

• 批准号: 1752995
• 负责人: Audrey Sawyer
• 金额: $ 54.76万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-03-15 至 2025-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1752995&HistoricalAwards=false
• 关键词: CAREER; Dynamic; water; table; controls

Water table fluctuations influence the transport of nutrients and contaminants between soils, groundwater, and surface water. The water table moves up and down over short and long timespans, particularly near rivers. Water table fluctuations introduce oxygen to shallow groundwater, which can react with ecologically important dissolved substances like organic carbon, nitrate, iron and manganese and have cascading effects on contaminants like arsenic. This project aims to understand how groundwater chemistry evolves in response to water table fluctuations over a range of timescales. Field observations, controlled laboratory column experiments, and computer models will quantify the movement of reactive solutes such as oxygen, nitrate, iron, and manganese beneath a fluctuating water table. Results will improve our understanding of dynamic changes in both groundwater and river water quality and the management of these vital water resources. This project will also introduce a broad audience of citizens and future scientists to dynamic surface water-groundwater interactions through the creation of a hands-on outdoor laboratory facility and museum exhibit. Water table fluctuations play an important role in reactive solute transport and water quality near rivers. When the water table rises, entrapped soil air exchanges oxygen with surrounding pore water, which travels downward when the water table falls. The enhanced supply of oxygen stimulates aerobic respiration, nitrification-denitrification, and oxidation of dissolved iron and manganese in groundwater. Water table fluctuations can propagate tens to hundreds of meters into an aquifer in response to changes in river stage. Yet the implications for reactive transport and water quality near rivers remain poorly understood. The overarching goal of this project is to quantify relationships between water table fluctuations, redox transformations, and solute export from aquifers to rivers. This project leverages novel sensor technology to observe the effects of water table fluctuations on groundwater chemistry in controlled column experiments and natural riparian aquifers. The four field sites in this study experience a range of water table fluctuations in response to tides, storms, and seasons. Each site has unique properties that influence reactive transport near the water table. However, pairs of sites also have commonalities in climate, lithology, catchment scale, land use, and geomorphology. Numerical fluid flow and reactive transport models will quantify dynamics in biogeochemical transformation rates and solute fluxes in these riparian aquifers. Observations and model results will be synthesized to generate a quantitative understanding of the effects of water table fluctuations on reactive solute transport in dynamic riparian aquifers.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.

地下水位的波动会影响土壤、地下水和地表水之间营养物质和污染物的迁移。地下水位在短时间和长时间内上下移动，特别是在河流附近。地下水位波动将氧气引入浅层地下水，氧气可以与有机碳、硝酸盐、铁和锰等具有生态重要性的溶解物质发生反应，并对砷等污染物产生级联效应。该项目旨在了解地下水化学如何在一系列时间尺度上响应地下水位波动而演变。现场观测、受控实验室柱实验和计算机模型将量化波动地下水位下活性溶质（如氧、硝酸盐、铁和锰）的运动。研究结果将提高我们对地下水和河流水质动态变化的理解，并有助于这些重要水资源的管理。该项目还将通过建立一个动手的户外实验室设施和博物馆展览，向广大市民和未来的科学家介绍地表水-地下水动态相互作用。 地下水位波动对河流附近的反应性溶质运移和水质起着重要作用。当地下水位上升时，截留的土壤空气与周围的孔隙水交换氧气，当地下水位福尔斯下降时，孔隙水向下流动。氧气供应的增加刺激了地下水中的好氧呼吸、硝化-反硝化以及溶解铁和锰的氧化。地下水位的波动可以传播到几十到几百米的含水层中，以响应河流水位的变化。然而，对河流附近的反应性运输和水质的影响仍然知之甚少。该项目的总体目标是量化地下水位波动，氧化还原转化和溶质从含水层到河流的出口之间的关系。该项目利用新型传感器技术，在受控柱实验和自然河岸含水层中观察地下水位波动对地下水化学的影响。在这项研究中的四个现场的经验，以应对潮汐，风暴和季节的地下水位波动范围。每个站点都有独特的属性，影响地下水位附近的反应运输。然而，成对的站点在气候、岩性、集水规模、土地利用和地貌方面也有共性。数值流体流动和反应输运模型将量化这些河岸含水层的地球化学转化率和溶质通量的动态。观测和模型结果将被合成，以产生一个定量的了解地下水位波动的影响，在动态河岸含水层的反应性溶质运移。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

项目成果

Groundwater‐stream connectivity from minutes to months across United States basins as revealed by spectral analysis

光谱分析显示，美国流域地下水流连通性从几分钟到几个月不等

• DOI: 10.1002/hyp.14514
• 发表时间: 2022
• 期刊: Hydrological Processes
• 影响因子: 3.2
• 作者: Clyne, Jacob B.;Sawyer, Audrey H.
• 通讯作者: Sawyer, Audrey H.

Nitrate Removal Within Heterogeneous Riparian Aquifers Under Tidal Influence

• DOI: 10.1029/2019gl085699
• 发表时间: 2020-05
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: C. Wallace;A. Sawyer;M. Soltanian;R. Barnes

A Model Analysis of the Tidal Engine That Drives Nitrogen Cycling in Coastal Riparian Aquifers

沿海河岸含水层驱动氮循环的潮汐发动机模型分析

• DOI: 10.1029/2019wr025662
• 发表时间: 2020
• 期刊: Water Resources Research
• 影响因子: 5.4
• 作者: Wallace, Corey D.;Sawyer, Audrey H.;Barnes, Rebecca T.;Soltanian, Mohamad Reza;Gabor, Rachel S.;Wilkins, Michael J.;Moore, Myles T.
• 通讯作者: Moore, Myles T.

On-Campus Field Experiences Help Students to Learn and Enjoy Water Science During the COVID-19 Pandemic

校园实地体验帮助学生在 COVID-19 大流行期间学习和享受水科学

• DOI: 10.3389/fenvs.2022.877327
• 发表时间: 2022
• 期刊: Frontiers in Environmental Science
• 影响因子: 4.6
• 作者: Saup, C.;Lamantia, K.;Chen, Z.;Bell, B.;Schulze, J.;Alsdorf, D.;Sawyer, A.H.
• 通讯作者: Sawyer, A.H.

Spectral analysis of continuous redox data reveals geochemical dynamics near the stream–aquifer interface

• DOI: 10.1002/hyp.13335
• 发表时间: 2018-12
• 期刊: Hydrological Processes
• 影响因子: 3.2
• 作者: C. Wallace;A. Sawyer;R. Barnes