Jason Kean
Biography
My research focuses on the processes controlling debris-flow initiation and growth, particularly after wildfire, but also in unburned areas. This research includes a field component that obtains direct measurements of debris flows in natural settings, a modeling component that seeks to explain the observations, and an applied component that focuses on assessment of debris-flow hazards. My previous research at the USGS focused on river mechanics, including bank erosion and the development of model-based approaches to gage streams and rivers.
Education:
University of Colorado, Ph.D., 2003, Civil Engineering
University of Colorado, M.S., 1998, Civil Engineering
Cornell University, B.S., 1994, Civil Engineering
Science and Products
Advancing Post-Fire Debris Flow Hazard Science with a Field Deployable Mapping Tool
Mapping the occurrence of post-fire flooding and debris flow is crucial for 1) integrating observations into models used to define rainfall thresholds for early warning, 2) understanding patterns of inundation, and 3) improving models for predictive hazard assessment. Despite the critical role mapping plays in post-fire hazard assessment and early warning, there has not been a standardized...
January 2021: Evaluation of debris flow activity in recent California Burn Areas following atomospheric river event
The January 2021 atmospheric river event produced heavy rainfall in some areas burned by wildfires in 2020. The Landslide Hazards Program (LHP) staff has evaluated the debris-flow activity in several areas. The locations are: The Carmel Fire, the CZU Lightning Complex Fire (San Mateo and Santa Cruz), the Dolan Fire, and the River Fire burn areas.
Reports by date are below. Photos will...
How Often Do Rainstorms Cause Debris Flows in Burned Areas of the Southwestern U.S.?
Debris flows, sometimes referred to as mudslides, mudflows, lahars, or debris avalanches, are common types of fast-moving landslides. They usually start on steep hillsides as a result of shallow landslides, or from runoff and erosion that liquefy and accelerate to speeds in excess of 35 mi/h. The consistency of debris flows ranges from thin, watery to thick, rocky mud that can carry large...
Emergency Assessment of Post-Fire Debris-Flow Hazards
Estimates of the probability and volume of debris flows that may be produced by a storm in a recently burned area, using a model with characteristics related to basin shape, burn severity, soil properties, and rainfall.
Wildfire can significantly alter the hydrologic response of a watershed to the extent that even modest rainstorms can produce dangerous flash floods and debris flows....
Chalk Cliffs, Colorado
Chalk Cliffs, located 8 miles southwest of Buena Vista, CO, is one of the most active debris-flow areas in the state.
Rainfall and Landslides in Southern California
A summary of recent and past landslides and debris flows caused by rainfall in Southern California.
Movement of sediment through a burned landscape: Sediment volume observations and model comparisons in the San Gabriel Mountains, California, USA
Post-wildfire changes to hydrologic and geomorphic systems can lead to widespread sediment redistribution. Understanding how sediment moves through a watershed is crucial for assessing hazards, developing debris flow inundation models, engineering sediment retention solutions, and quantifying the role that disturbances play in landscape evolution...
Rengers, Francis K.; McGuire, Luke A.; Kean, Jason W.; Staley, Dennis M.; Dobre, Mariana; Robichaud, Peter R.; Swetnam, Tyson Postwildfire soil‐hydraulic recovery and the persistence of debris flow hazards
Deadly and destructive debris flows often follow wildfire, but understanding of changes in the hazard potential with time since fire is poor. We develop a simulation‐based framework to quantify changes in the hydrologic triggering conditions for debris flows as postwildfire infiltration properties evolve through time. Our approach produces time‐...
Thomas, Matthew A.; Rengers, Francis K.; Kean, Jason W.; McGuire, Luke A.; Staley, Dennis M.; Barnhart, Katherine R.; Ebel, Brian A.
U.S. Geological Survey wildland fire science strategic plan, 2021–26
The U.S. Geological Survey (USGS) Wildland Fire Science Strategic Plan defines critical, core fire science capabilities for understanding fire-related and fire-responsive earth system processes and patterns, and informing management decision making. Developed by USGS fire scientists and executive leadership, and informed by conversations with...
Steblein, Paul F.; Loehman, Rachel A.; Miller, Mark P.; Holomuzki, Joseph R.; Soileau, Suzanna C.; Brooks, Matthew L.; Drane-Maury, Mia; Hamilton, Hannah M.; Kean, Jason W.; Keeley, Jon E.; Mason, Robert R.; McKerrow, Alexa J.; Meldrum, James R.; Molder, Edmund B.; Murphy, Sheila F.; Peterson, Birgit; Plumlee, Geoffrey S.; Shinneman, Douglas J.; van Mantgem, Phillip J.; York, Alison Forecasting the frequency and magnitude of postfire debris flows across southern California
Southern California has a long history of damaging debris flows after wildfire. Despite recurrent loss, forecasts of the frequency and magnitude of postfire debris flows are not available for the region like they are for earthquakes. Instead, debris flow hazards are typically assessed in a reactive manner after wildfires. Such assessments are...
Kean, Jason W.; Staley, Dennis M. Time since burning and rainfall characteristics impact post-fire debris flow initiation and magnitude
The extreme heat from wildfire alters soil properties and incinerates vegetation, leading to changes in infiltration capacity, ground cover, soil erodibility, and rainfall interception. These changes promote elevated rates of runoff and sediment transport that increase the likelihood of runoff-generated debris flows. Debris flows are most common...
McGuire, Luke A.; Rengers, Francis K.; Oakley, Nina S.; Kean, Jason W.; Staley, Dennis M.; Tang, Hui; de Orla-Barile, Marian; Youberg, Ann M. Progress and lessons learned from responses to landslide disasters
Landslides have the incredible power to transform landscapes and also, tragically, to cause disastrous societal impacts. Whereas the mechanics and effects of many landslide disasters have been analyzed in detail, the means by which landslide experts respond to these events has garnered much less attention. Herein, we evaluate nine landslide...
Collins, Brian D.; Reid, Mark E.; Coe, Jeffrey A.; Kean, Jason W.; Baum, Rex L.; Jibson, Randall W.; Godt, Jonathan W.; Slaughter, Stephen; Stock, Greg M. Measuring basal force fluctuations of debris flows using seismic recordings and empirical green's functions
We present a novel method for measuring the fluctuating basal normal and shear stresses of debris flows by using along‐channel seismic recordings. Our method couples a simple parameterization of a debris flow as a seismic source with direct measurements of seismic path effects using empirical Green's functions generated with a force hammer. We...
Allstadt, Kate; Farin, Maxime; Iverson, Richard M.; Obryk, Maciej; Kean, Jason W.; Tsai, Victor C.; Rapstine, Thomas D; Logan, Matthew The recurrence interval of post-fire debris-flow generating rainfall in the southwestern United States
In the southwestern United States, post-fire debris flows commonly initiate during short bursts of intense rainfall. To date, the frequency of the rainfall rates has not been quantified. Here, we combine an existing database of debris-flow occurrences and corresponding peak storm intensities with a geospatial library of rainfall recurrence...
Staley, Dennis M.; Kean, Jason W.; Rengers, Francis K. Landslides after wildfire: Initiation, magnitude, and mobility
In the semiarid Southwestern USA, wildfires are commonly followed by runoff-generated debris flows because wildfires remove vegetation and ground cover, which reduces soil infiltration capacity and increases soil erodibility. At a study site in Southern California, we initially observed runoff-generated debris flows in the first year following...
Rengers, Francis K.; McGuire, Luke; Oakley, Nina S.; Kean, Jason W.; Staley, Dennis M.; Tang, Hui The impact of sediment supply on the initiation and magnitude of runoff-generated debris flows
Rainfall intensity‐duration (ID) thresholds are commonly used to assess the potential for runoff‐generated debris flows, but the sensitivity of these thresholds to sediment supply, which can change rapidly with time, is relatively unexplored. Furthermore, debris flows often self‐organize into distinct surges, but the factors controlling the...
Tang, Hui; McGuire, Luke A.; Kean, Jason W.; Smith, Joel B. The influence of frost weathering on the debris flow sediment supply in an alpine basin
Rocky, alpine mountains are prone to mass wasting from debris flows. The Chalk Cliffs study area (central Colorado, USA) produces debris flows annually. These debris flows are triggered when overland flow driven by intense summer convective storms mobilizes large volumes of sediment within the channel network. Understanding the debris flow...
Rengers, Francis K.; Kean, Jason W.; Reitman, Nadine G.; Smith, Joel B.; Coe, Jeffrey A.; McGuire, Luke Thresholds for post-wildfire debris flows: Insights from the Pinal Fire, Arizona, USA
Wildfire significantly alters the hydrologic properties of a burned area, leading to increases in overland flow, erosion, and the potential for runoff-generated debris flows. The initiation of debris flows in recently burned areas is well-characterized by rainfall intensity-duration (ID) thresholds. However, there is currently a paucity of data...
Raymond, Carissa A; McGuire, Luke A.; Youberg, Ann M.; Staley, Dennis M.; Kean, Jason W.
Post-wildfire debris flow: 2016 Fish Fire, Las Lomas Canyon
The June 2016 Fish Fire burned over 12 km^2 in Los Angeles County, California. After the fire, the USGS installed an automated rain-triggered camera to monitor post-wildfire flooding and debris flow in a small canyon above the Las Lomas debris basin in Duarte. This video shows the peak flow triggered by an intense rainstorm on January 20, 2017.
Post-Wildfire Debris Flood: 2016 Fish Fire, Van Tassel Canyon, CA
The June 2016 Fish Fire burned over 12 km^2 in Los Angeles County, California. After the fire, the USGS installed an automated rain-triggered camera and laser stage gage to monitor post-wildfire flooding and debris flow in Van Tassel Canyon near Azusa. This video shows the peak flow triggered by an intense rainstorm on January 20, 2017. The laser stage gage, which is
Post-wildfire Flood and Debris Flow: 2014 Silverado Fire
In 2014, the Silverado Fire burned approximately 4 km^2 in Orange County, California. After the fire, the USGS installed an automated rain-triggered camera to monitor post-wildfire flooding and debris flow at the outlet of a small 0.6 km^2 basin within the burn area. This video shows the initial surge and peak flow triggered by an intense rainstorm on July 19, 2015. The
Debris Flow Monitoring at Chalk Cliffs, CO (2014)
The USGS and its cooperators have installed debris-flow monitoring equipment in the largest drainage basin at Chalk Cliffs, CO. Data collection at this site supports research on the hydrologic factors that control debris-flow initiation, entrainment, and flow dynamics.
This debris flow took place August 1, 2014. The video includes two different views of an
Post-wildfire Landslides Becoming More Frequent in Southern California
Southern California can now expect to see post-wildfire landslides occurring almost every year, with major events expected roughly every ten years, a new study led by U.S. Geological Survey researchers finds.