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Graduate Defense: Luke Telfer
October 20, 2021 @ 3:00 pm - 4:00 pm MDT
Title: Exploring Hydrologic Responses to Different Wildfire Spatial Patterns Through the Lens of Computational Modeling
Program: Master of Science in Hydrologic Sciences
Advisor: Dr. Alejandro Flores, Geosciences
Committee Members: Dr. Jen Pierce, Geosciences, and Dr. Megan Cattau, College of Innovation and Design
Wildfires disrupt watershed hydrologic processes by removing vegetation and altering soil properties, threatening downstream water resources and increasing the risk of destructive postfire erosion and flooding. Plot-scale postfire effects on runoff, infiltration, and evapotranspiration are well-documented; yet watershed-scale hydrologic responses remain highly uncertain. Part of this uncertainty lies with a poor understanding of how postfire spatial patterns influence water transfer pathways and flow patterns due to challenges associated with measuring and comparing wildfire disturbances. In this study, we use a physically-based hydrologic model to simulate an idealized, snow-dominated mountain watershed under a controlled suite of postfire landscape patterns. We found that a fire’s spatial arrangement determined the size of its disturbance flow path network, defined as the burned area and all hydrologically-connected unburned sites. The size of the disturbance flow path network controlled the timing of watershed discharge and changes in soil water storage, driven by earlier snowmelt onset in the burned areas. The importance of these indirectly affected unburned areas should be considered when attempting to quantify postfire spatial patterns in watershed-scale hydrological contexts.