Laboratory Experiments to Understand Post-Wildfire Processes on Soil Sealing for Hydrologic Fluxes in Complex Terrain

通过实验室实验了解复杂地形中水文通量的野火后土壤封闭过程

• 批准号: 2136339
• 负责人: Ryan Webb
• 金额: $ 30.75万
• 依托单位: University of Wyoming
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2136339&HistoricalAwards=false
• 关键词: Laboratory; Experiments; Understand; Post; Wildfire

It is well understood that floods and erosion following a wildfire can be costly to local communities. However, the specific processes that alter soil characteristics to increase flooding and erosion are not well understood. Soil sealing is one of the less studied post-wildfire processes because the peak impact of soil sealing occurs immediately after a wildfire when it can be difficult and dangerous to make field observations. However, this time period immediately after a wildfire also holds the highest risk for high damage flooding due to the lack of vegetation. To investigate the soil sealing processes that occur immediately after a wildfire, the investigators in this project will conduct laboratory experiments to simulate rainfall on burned soils and ash materials. The outcomes will provide new information about post-wildfire soil sealing processes with implications for forest management and disaster mitigation. Additionally, this project will support the development of technical skills for four college students and the development of a 4th and 5th grade science lesson on soil erosion.The overarching research question of this project is: how does the slope angle of a land surface affect soil sealing processes immediately after a wildfire, and how does this impact infiltration for consequent rain events? As slope angle increases, surface ash erosion rates will increase. As a result, it is hypothesized that soil surfaces that experience increased storage of ash will promote soil sealing processes that decrease infiltration during later rain events, thereby increasing runoff. To test this hypothesis, laboratory scale rainfall simulations will be conducted at a range of slope angles on simulated burned soil conditions. Investigators will observe the effect of slope angle by (1) quantifying the effect of slope angle on surface ash erosion and surface storage through rainfall experiments, and (2) determining the effect of ash retention, if any, on soil properties after rainfall experiments. This project is jointly funded by Hydrologic Sciences and the Established Program to Stimulate Competitive Research (EPSCoR).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.

众所周知，野火后的洪水和侵蚀可能会给当地社区带来高昂的代价。然而，改变土壤特性以增加洪水和侵蚀的具体过程还没有得到很好的理解。土壤密封是野火后研究较少的过程之一，因为土壤密封的峰值影响发生在野火后立即进行现场观察是困难和危险的。然而，由于缺乏植被，野火之后的这段时间也是高破坏洪水的最高风险。为了研究野火后立即发生的土壤密封过程，该项目的研究人员将进行实验室实验，模拟燃烧土壤和灰烬材料上的降雨。这些成果将提供有关野火后土壤封闭过程的新信息，并对森林管理和减灾产生影响。此外，该项目将支持四名大学生的技术技能的发展和发展的第四和第五年级的科学课上土壤侵蚀。该项目的首要研究问题是：如何土地表面的坡度角影响土壤密封过程后立即野火，这是如何影响渗透随之而来的降雨事件？随着坡角的增大，地表灰侵蚀速率增大。因此，据推测，土壤表面的经验增加存储的灰将促进土壤密封过程，减少在以后的降雨事件的渗透，从而增加径流。为了检验这一假设，将在模拟火烧土条件下，以一系列坡度进行实验室规模的降雨模拟。调查人员将通过以下方式观察坡度的影响：（1）通过降雨实验量化坡度对表面灰侵蚀和表面储存的影响，以及（2）确定降雨实验后灰滞留对土壤性质的影响（如果有的话）。该项目由水文科学和促进竞争性研究的既定计划（EPSCoR）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知识价值和更广泛的影响审查标准进行评估，被认为值得支持。