EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Post-fire infiltration modeling – some soil physical considerations

Markus Berli1, Rose M. Shillito1,2, Jeremy J. Giovando3, Nawa Pradhan2, Jang H. (“Jay”) Pak4, Ian E. Floyd2, and Kumud Acharya1
Markus Berli et al.
  • 1Desert Research Institute (DRI), Hydrologic Sciences, Las Vegas NV, United States of America
  • 2US Army Corps of Engineers (USACE), Engineering Research and Development Center (ERDC), Costal Hydrology Laboratory (CHL), Vicksburg MS, United States of America
  • 3US Army Corps of Engineers (USACE), Engineering Research and Development Center (ERDC), Cold Regions Reserach and Engineering Laboratory (CRREL), Hanover NH, United States of America
  • 4US Army Corps of Engineers (USACE), Institute for Water Resources, Hydraulic Engineering Center (HEC), Davis CA, United States of America

Wildfires can change watershed hydrologic processes and increase the risks for soil erosion, flooding and debris flow after a fire. While fire-induced changes to the soil have significant effects on infiltration and runoff, the physical mechanisms remain unclear. A growing body of research suggests these mechanisms include soil water repellency (SWR) and the alteration of soil structure. The objective of this study was to relate SWR, soil structure, soil moisture to infiltration using a process-based, soil physics approach to better model infiltration into fire-affected soil, The ultimate goal is to improve the prediction of post-fire runoff with process-based hydrology models. Our research shows the effects of SWR and soil structure on infiltration can be captured by the soil hydraulic parameters of sorptivity and hydraulic conductivity, respectively. SWR reduces sorptivity and controls the early stage of infiltration during a storm. Changes in soil structure affect hydraulic conductivity and later stages of infiltration. Additionally, results show SWR can have an effect on unsaturated hydraulic conductivity but does not significantly affect saturated hydraulic conductivity. The study also highlights the important role soil water content plays for post-fire infiltration since both sorptivity and unsaturated hydraulic conductivity are functions of soil water content.

How to cite: Berli, M., Shillito, R. M., Giovando, J. J., Pradhan, N., Pak, J. H. (., Floyd, I. E., and Acharya, K.: Post-fire infiltration modeling – some soil physical considerations, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13805,, 2021.