EAR-PF Subsurface Nitrous Oxide Emissions Along River Corridors: Analysis Across Spatial and Temporal Scales

EAR-PF 河流走廊沿线地下一氧化二氮排放：跨空间和时间尺度的分析

• 批准号: 1855193
• 负责人: Corey Wallace
• 金额: $ 17.4万
• 依托单位: Wallace, Corey David
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1855193&HistoricalAwards=false
• 关键词: EAR; PF; Subsurface; Nitrous; Oxide

Dr. Corey D. Wallace has been granted an NSF EAR Postdoctoral Fellowship to work at the University of Cincinnati to examine how agricultural practices and changes in precipitation patterns affect nitrous oxide production along rivers. Some evidence suggests that fertilizers from agricultural activities near streams could contribute to the release of greenhouse gases to the atmosphere, a process that has accelerated as human food and energy demands have increased. Surface water and groundwater mixing along rivers delivers this nitrogen to river beds and banks, where it stimulates the formation of nitrogen gases. The release may be influenced by the amount of rainfall, the characteristics of the soil, and type of land use. Through experimental, field work, and modeling activities, this work will study how streams contribute to the release of greenhouse gases into the atmosphere and how such emissions might change in the future. Results from this work will advance knowledge on how greenhouse gases are released to the atmosphere and will contribute to the development of management strategies to reduce these emissions. The postdoctoral fellow will also enhance graduate and undergraduate education by hosting a field and classroom-based course on the environmental effects of climate change and agriculture.As a redox process, the extent and magnitude of subsurface nitrogen cycling changes with nutrient availability and groundwater flow patterns. Subsequent nitrous oxide production is thus highly variable across spatial and temporal scales. The working hypotheses of this study include: (a) sediment heterogeneity increases subsurface nitrous oxide flux relative to a homogenous lithology in an otherwise analogous geochemical environment, and (b) climate change related shifts in precipitation patterns increase nitrous oxide flux along river corridors, creating a positive feedback loop that further stimulates climate change. The postdoctoral fellow will utilize the CV Theis Groundwater Observatory at the University of Cincinnati to evaluate the riparian aquifer adjacent to the Great Miami River at high spatial and temporal resolution and elucidate the hydrologic and geochemical controls on nitrous oxide yield from subsurface nitrogen cycling. These field measurements will inform numerical model development, which in turn will provide information on the influence of sediment heterogeneity and other factors on nitrous oxide production. Watershed-scale effects will be assessed by concomitantly using simulated future climate data and projected land use change to estimate nitrous oxide flux along river corridors.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.

科里·D博士华莱士已获得美国国家科学基金会博士后奖学金，在辛辛那提大学工作，研究农业实践和降水模式的变化如何影响沿着的一氧化二氮生产。一些证据表明，溪流附近的农业活动产生的肥料可能有助于向大气中释放温室气体，随着人类粮食和能源需求的增加，这一过程已经加速。地表水和地下水沿着沿着混合，将氮输送到河床和河岸，在那里刺激氮气的形成。释放量可能受到降雨量、土壤特性和土地使用类型的影响。通过实验，实地工作和建模活动，这项工作将研究流如何促进温室气体释放到大气中，以及这些排放在未来可能如何变化。这项工作的结果将增进关于温室气体如何释放到大气中的知识，并将有助于制定减少这些排放的管理战略。博士后研究员还将通过举办关于气候变化和农业的环境影响的实地和课堂课程来加强研究生和本科生教育。作为一个氧化还原过程，地下氮循环的程度和幅度随着营养物质的可用性和地下水流动模式而变化。因此，随后的一氧化二氮生产在空间和时间尺度上变化很大。这项研究的工作假设包括：（a）沉积物的异质性增加地下一氧化二氮通量相对于一个均匀的岩性，否则类似的地球化学环境，和（B）气候变化相关的变化，降水模式增加一氧化二氮通量沿着河流走廊，创造一个积极的反馈回路，进一步刺激气候变化。博士后研究员将利用CV泰斯地下水观测站在辛辛那提大学，以高空间和时间分辨率评估毗邻大迈阿密河的河岸含水层，并阐明地下氮循环对一氧化二氮产量的水文和地球化学控制。这些实地测量将为数值模型的开发提供信息，而数值模型的开发又将提供关于沉积物异质性和其他因素对一氧化二氮产生的影响的信息。流域尺度的影响将通过同时使用模拟的未来气候数据和预计的土地利用变化来评估，以估计沿着河流走廊的一氧化二氮通量。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估的支持。

项目成果

Underlying riparian lithology controls redox dynamics during stage-driven mixing

• DOI: 10.1016/j.jhydrol.2021.126035
• 发表时间: 2021-02
• 期刊: Journal of Hydrology
• 影响因子: 6.4
• 作者: C. Wallace;M. Soltanian

Surface water‐groundwater exchange dynamics in buried‐valley aquifer systems

埋藏—山谷含水层系统中的地表水—地下水交换动态

• DOI: 10.1002/hyp.14066
• 发表时间: 2021
• 期刊: Hydrological Processes
• 影响因子: 3.2
• 作者: Wallace, Corey D.;Soltanian, Mohamad Reza
• 通讯作者: Soltanian, Mohamad Reza