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

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.