CAREER: Multi-physical and Multi-scale Testing and Modeling of Water Infiltration through Frozen Soils

该学院早期职业发展（CAREER）奖支持的研究将阐明导致春季洪水的地质水文问题背后的基本现象，特别是由于冻结和解冻造成的水力滞后如何影响冻土并改变水渗透。由于气候变化的影响迅速增加，这在今天至关重要。在寒冷地区，冻土控制着融雪通量在地表径流和入渗之间的分配。控制地下热通量的主要机制是与冻结和融化有关的热传导。然而，流动的水可以通过平流在雪融化引起的水渗透期间传递大量的热量。从长远来看，该项目将有助于多个利益攸关方（例如，环境机构监管机构和政府，受影响的社区和非政府组织），促进科学进步，促进国家健康，繁荣和福利。教育活动还将对教育和公共知识产生重大影响。这项工作将为K-12学生提供一个可持续的外展模块，该模块可以在其他环境以及本科和研究生课程，课程模块和研究培训经验中实施。这项CAREER奖的研究目标是：1）了解土壤冻结过程中土壤颗粒与非饱和状态水冰基质的微观界面行为和冻结过程中的水分渗透-2）确定与孔隙分布、热性质和冻结前湿度有关的选定土壤的土壤冻结特征曲线和土壤水分特征曲线的滞后; 3）阐明温度循环期间非饱和水渗入冻土的动力学;以及4）用实验室实验结果增强现有的水热耦合模拟方案，以明确地预测通过土壤的水流并识别所选变量的敏感性。该奖项将支持第一个综合性的工作，将孔隙尺度的观察/建模，实验室规模的实验室实验，以及水渗透到冻土的多物理建模，以阐明形成土壤-水-冰-孔隙基质的多个组分之间的相互关系。这项工作将加强对渗流带系统的水渗透的评估和分析，以加快其在实践中的采用，从而促进洪水预测，可持续农业，以及减轻采矿，自然灾害和侵蚀领域的气候变化影响。机械和制造创新（CMMI）部门和既定计划，以刺激竞争力的研究（EPSCoR）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。

This Faculty Early Career Development (CAREER) award supports research that will elucidate fundamental phenomena behind the geo-hydrological issues contributing to spring floods, particularly how hydraulic hysteresis due to freezing and thawing impacts frozen soils and changes water infiltration. This is crucial today due to the quickly increasing effect of climate change. In cold regions, frozen soil controls the partitioning of snowmelt flux between surface runoff and infiltration. The primary mechanism controlling the ground heat flux is thermal conduction associated with freezing and thawing. However, flowing water can transfer substantial heat by advection during water infiltration induced by snow melting. In the long term, this project will contribute to cost-effectiveness and sustainability for multiple stakeholders (e.g., environmental agency regulators and governments, impacted communities, and nongovernmental organizations), promote science’s progress, and advance national health, prosperity, and welfare. The educational activities will also significantly impact education and public knowledge. This work will result in a sustainable outreach module for K-12 students that could be implemented in other settings and undergraduate and graduate courses, course modules, and research training experiences.The research objectives of this CAREER award are to: 1) understand microscale interfacial behavior of a soil particle and water-ice matrix in the unsaturated state during the soil-freezing process and water infiltration in freezing-thawing cycles; 2) determine the hysteresis of the Soil-Freezing Characteristic Curve and the Soil Water Characteristic Curve of selected soils associated with pore distribution, thermal properties, and pre-freezing moisture; 3) elucidate the dynamics of unsaturated water infiltration into frozen soils during temperature cycles; and 4) enhance an existing hydro-thermal coupled modeling scheme with laboratory experiment results to explicitly predict water flow through soils and identify the sensitivity of selected variables. This award will support the first comprehensive work to integrate pore-scale observation/modeling, bench-scale lab experiments, and multiphysical modeling of water infiltration into frozen soils to elucidate interrelations among the multiple components forming a soil-water-ice-pore matrix. The work will enhance the assessment and analysis of water infiltration through a vadose zone system to expedite its adoption in practice, thus promoting flood prediction, sustainable agriculture, and mitigation of climate change impacts in the mining, natural hazard, and erosion fields.This project is jointly funded by the Engineering for Civil, Mechanical and Manufacturing Innovation (CMMI) Division 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.