Meltwater Infiltration in Layered Snow Analogs Using a Quasi-2D Flow Cell

This project examines the interaction between meltwater infiltration and stratified snowpack using a quasi-2D flow cell filled with two distinct layers of glass beads as a controlled snow analog. The goal was to understand how hydraulic barriers (coarse → fine) and capillary barriers (fine → coarse) affect preferential flow pathways, infiltration velocities, and fluid ponding at layer transitions. I assembled the experimental setup, including the flow cell, rain-chamber infiltration system, dyed water mixture, and an automated 10-second-interval imaging system using a Canon DSLR. Over the summer, I ran experiments across six bead-layer configurations and multiple flow rates. These trials revealed the formation of distinct gravity-driven meltwater “fingers” whose width and velocity depended strongly on bead diameter and layer arrangement. I processed image sequences in ImageJ to measure finger widths and used Python scripts to compute front velocities in each layer. My results show that larger bead diameters produce narrower, faster-moving fingers, and that transitions from coarse to fine media induce ponding and delayed breakthrough. The data collected fills an important gap in existing experimental snow hydrology: centimeter-scale behavior at layer interfaces. These findings support the Fu Group’s development of more accurate numerical models of snowmelt infiltration, which has implications for predicting water storage and runoff in mountain snowpacks that supply much of California’s freshwater. Here is my final report for this project.