Jason Kean
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 and Certifications
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
Postfire debris-flow hazard maps
Wildfires can dramatically alter how water moves across the landscape. As a result, even modest rainstorms can trigger dangerous flash floods and debris flows in steep burned areas. In response, the USGS produces postfire debris-flow hazard assessments for recently burned areas. These hazard assessments estimate the likelihood, volume, and combined hazard of debris-flows in recently burned. This...
Improving Postfire Debris-Flow Hazard Assessments In The Pacific Northwest Through Application Of Debris-Flow Models
As part of the Post-fire Hazards and Impacts to Resources and Ecosystems (PHIRE): Support for Response, Recovery, and Mitigation Project, the PHIRE Debris Flow Hazard team is engaging in several studies to better understand the spatial and temporal drivers of postfire debris flows and improve postfire hazard assessments across northern California and the Pacific Northwest.
Calwood Fire "Heil Ranch" Landslide Monitoring Site near Boulder, CO
Wildfire can radically change a mountainous landscape such that even a modest rainstorm is capable of producing deadly and destructive flash flooding and debris flows.
Postfire Landslide Monitoring Station: "Chips" (2021 Dixie Fire) near Belden, CA
Wildfire can increase landslide susceptibility in mountainous terrain. The USGS maintains postfire landslide monitoring stations to track hillslope hydrologic conditions in the years following fire.
Postfire Landslide Monitoring Station: "Chambers" (2021 Dixie Fire) near Belden, CA
Wildfire can increase landslide susceptibility in mountainous terrain. The USGS maintains postfire landslide monitoring stations to track hillslope hydrologic conditions in the years following fire.
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...
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 items...
Postfire debris-flow hazards
Wildfires can dramatically alter how water moves across the landscape. After a fire, vegetation is removed and soil properties change, reducing the ground’s ability to absorb rainfall. As a result, even modest rainstorms can trigger dangerous flash floods and debris flows in steep burned areas. Postfire debris flows are fast-moving mixtures of water, mud, rocks, and vegetation that can surge...
2009 Station Fire, Dunsmore Canyon, Glendale, California
In 2009, the Station Fire burned 160,000 acres in the San Gabriel Mountains. Vegetation has started to return, but it can take many years for a basin to fully recover from the effects of fire.
Reconstruction of an Avalanche: The West Salt Creek Rock Avalanche
Release Date: MAY 25, 2016 The West Salt Creek Rock Avalanche, Colorado, May 25, 2014
Rainfall and Landslides in Southern California
Southern California is well known to be susceptible to landslides, especially during periods of intense or prolonged rainfall, and these hazards can worsen during El Niño conditions. This page summarizes the causes and impacts of historical and recent rainfall-triggered landslides and debris flows in southern California, including several major winter storms that caused damaging and deadly events...
Filter Total Items: 33
No Result Found
Filter Total Items: 104
Measuring basal force fluctuations of debris flows using seismic recordings and empirical green's functions 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 test this method using two large‐scale (8...
Authors
Kate E. Allstadt, Maxime Farin, Richard M. Iverson, Maciej K. Obryk, Jason W. Kean, Victor C. Tsai, Thomas D Rapstine, Matthew Logan
The recurrence interval of post-fire debris-flow generating rainfall in the southwestern United States 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 interval (RI) information and climate type to...
Authors
Dennis M. Staley, Jason W. Kean, Francis K. Rengers
Landslides after wildfire: Initiation, magnitude, and mobility 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 fire. However, at the same site three years...
Authors
Francis K. Rengers, Luke McGuire, Nina S. Oakley, Jason W. Kean, Dennis M. Staley, Hui Tang
The impact of sediment supply on the initiation and magnitude of runoff-generated debris flows 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 magnitude and frequency of these surges...
Authors
Hui Tang, Luke A. McGuire, Jason W. Kean, Joel B. Smith
The influence of frost weathering on the debris flow sediment supply in an alpine basin 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 hazard in this, and similar alpine settings...
Authors
Francis K. Rengers, Jason W. Kean, Nadine G. Reitman, Joel B. Smith, Jeffrey A. Coe, Luke McGuire
Conceptual framework for assessing disturbance impacts on debris-flow initiation thresholds across hydroclimatic settings Conceptual framework for assessing disturbance impacts on debris-flow initiation thresholds across hydroclimatic settings
The destructive and deadly nature of debris flows has motivated research into empirical rainfall thresholds to provide situational awareness, inform early warning systems, and reduce loss of life and property. Disturbances such as wildfire and land-cover change can influence the hydrological processes of infiltration and runoff generation; in steep terrain this typically lowers empirical
Authors
Benjamin B. Mirus, Dennis M. Staley, Jason W. Kean, Joel B. Smith, Rick Wooten, Luke A. McGuire, Brian A. Ebel
Overcoming barriers to progress in seismic monitoring and characterization of debris flows and lahars Overcoming barriers to progress in seismic monitoring and characterization of debris flows and lahars
Debris flows generate seismic signals that contain valuable information about events as they unfold. Though seismic waves have been used for along-channel debris-flow and lahar monitoring systems for decades, it has proven difficult to move beyond detection to more quantitative characterizations of flow parameters and event size. This is for two primary reasons: (1) our limited...
Authors
Kate E. Allstadt, Maxime Farin, Andrew Lockhart, Sara K. McBride, Jason W. Kean, Richard M. Iverson, Matthew Logan, Joel B. Smith, Victor C. Tsai, David L. George
Thresholds for post-wildfire debris flows: Insights from the Pinal Fire, Arizona, USA 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 quantifying the rainfall intensities...
Authors
Carissa A Raymond, Luke A. McGuire, Ann M. Youberg, Dennis M. Staley, Jason W. Kean
Developing and testing physically based triggering thresholds for runoff‐generated debris flows Developing and testing physically based triggering thresholds for runoff‐generated debris flows
Runoff in steep channels is capable of transitioning into debris flows with hazardous implications for downstream communities and infrastructure, particularly in alpine landscapes with minimal vegetation and areas recently disturbed by wildfire. Here, we derive thresholds for the initiation of runoff‐generated debris flows based on critical values of dimensionless discharge and Shields...
Authors
Hui Tang, Luke A. McGuire, Francis K. Rengers, Jason W. Kean, Dennis M. Staley, Joel B. Smith
Exploring controls on debris-flow surge velocity and peak discharge at Chalk Cliffs, Colorado, USA Exploring controls on debris-flow surge velocity and peak discharge at Chalk Cliffs, Colorado, USA
We present a series of debris-flow events and use combined sensor and video data to explore how sediment concentration and triggering rainfall intensity affect the velocity and discharge of debris-flow surges generated by surface-water runoff. We analyze an initial data set of 49 surges from four debris-flow events recorded by a monitoring system at Chalk Cliffs, Colorado and compare...
Authors
Joel B. Smith, Jason W. Kean, Jeffrey A. Coe
A 4000-year history of debris flows in north-central Washington State, U.S.A.: Preliminary results from trenching and surficial geologic mapping at the Pope Creek fan A 4000-year history of debris flows in north-central Washington State, U.S.A.: Preliminary results from trenching and surficial geologic mapping at the Pope Creek fan
Long-term records of the magnitude and frequency of debris flows on fans are rare, but such records provide critical information needed for debris-flow hazard and risk assessments. This study explores the history of debris flows on a fan with seasonally inhabited cabins at Pope Creek along the Entiat River about 48 km upstream from the town of Entiat, Washington. Motivation for this...
Authors
Jeffrey A. Coe, Erin Bessette-Kirton, Stephen Slaughter, Francis K. Rengers, Trevor A. Contreras, Katherin A Michelson, Emily M. Taylor, Jason W. Kean, Kara Jacobacci, Molly A Hanson
An evaluation of debris-flow runout model accuracy and complexity in Montecito, CA: Towards a framework for regional inundation-hazard forecasting An evaluation of debris-flow runout model accuracy and complexity in Montecito, CA: Towards a framework for regional inundation-hazard forecasting
Numerous debris-flow inundation models have been applied retroactively to noteworthy events around the world. While such studies can be useful in identifying controlling factors, calibrating model parameters, and assessing future hazards in specific study areas, model parameters tailored to individual events can be difficult to apply regionally. The advancement of debris-flow modeling...
Authors
Erin Bessette-Kirton, Jason W. Kean, Jeffrey A. Coe, Francis K. Rengers, Dennis M. Staley
Science and Products
Postfire debris-flow hazard maps
Wildfires can dramatically alter how water moves across the landscape. As a result, even modest rainstorms can trigger dangerous flash floods and debris flows in steep burned areas. In response, the USGS produces postfire debris-flow hazard assessments for recently burned areas. These hazard assessments estimate the likelihood, volume, and combined hazard of debris-flows in recently burned. This...
Improving Postfire Debris-Flow Hazard Assessments In The Pacific Northwest Through Application Of Debris-Flow Models
As part of the Post-fire Hazards and Impacts to Resources and Ecosystems (PHIRE): Support for Response, Recovery, and Mitigation Project, the PHIRE Debris Flow Hazard team is engaging in several studies to better understand the spatial and temporal drivers of postfire debris flows and improve postfire hazard assessments across northern California and the Pacific Northwest.
Calwood Fire "Heil Ranch" Landslide Monitoring Site near Boulder, CO
Wildfire can radically change a mountainous landscape such that even a modest rainstorm is capable of producing deadly and destructive flash flooding and debris flows.
Postfire Landslide Monitoring Station: "Chips" (2021 Dixie Fire) near Belden, CA
Wildfire can increase landslide susceptibility in mountainous terrain. The USGS maintains postfire landslide monitoring stations to track hillslope hydrologic conditions in the years following fire.
Postfire Landslide Monitoring Station: "Chambers" (2021 Dixie Fire) near Belden, CA
Wildfire can increase landslide susceptibility in mountainous terrain. The USGS maintains postfire landslide monitoring stations to track hillslope hydrologic conditions in the years following fire.
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...
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 items...
Postfire debris-flow hazards
Wildfires can dramatically alter how water moves across the landscape. After a fire, vegetation is removed and soil properties change, reducing the ground’s ability to absorb rainfall. As a result, even modest rainstorms can trigger dangerous flash floods and debris flows in steep burned areas. Postfire debris flows are fast-moving mixtures of water, mud, rocks, and vegetation that can surge...
2009 Station Fire, Dunsmore Canyon, Glendale, California
In 2009, the Station Fire burned 160,000 acres in the San Gabriel Mountains. Vegetation has started to return, but it can take many years for a basin to fully recover from the effects of fire.
Reconstruction of an Avalanche: The West Salt Creek Rock Avalanche
Release Date: MAY 25, 2016 The West Salt Creek Rock Avalanche, Colorado, May 25, 2014
Rainfall and Landslides in Southern California
Southern California is well known to be susceptible to landslides, especially during periods of intense or prolonged rainfall, and these hazards can worsen during El Niño conditions. This page summarizes the causes and impacts of historical and recent rainfall-triggered landslides and debris flows in southern California, including several major winter storms that caused damaging and deadly events...
Filter Total Items: 33
No Result Found
Filter Total Items: 104
Measuring basal force fluctuations of debris flows using seismic recordings and empirical green's functions 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 test this method using two large‐scale (8...
Authors
Kate E. Allstadt, Maxime Farin, Richard M. Iverson, Maciej K. Obryk, Jason W. Kean, Victor C. Tsai, Thomas D Rapstine, Matthew Logan
The recurrence interval of post-fire debris-flow generating rainfall in the southwestern United States 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 interval (RI) information and climate type to...
Authors
Dennis M. Staley, Jason W. Kean, Francis K. Rengers
Landslides after wildfire: Initiation, magnitude, and mobility 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 fire. However, at the same site three years...
Authors
Francis K. Rengers, Luke McGuire, Nina S. Oakley, Jason W. Kean, Dennis M. Staley, Hui Tang
The impact of sediment supply on the initiation and magnitude of runoff-generated debris flows 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 magnitude and frequency of these surges...
Authors
Hui Tang, Luke A. McGuire, Jason W. Kean, Joel B. Smith
The influence of frost weathering on the debris flow sediment supply in an alpine basin 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 hazard in this, and similar alpine settings...
Authors
Francis K. Rengers, Jason W. Kean, Nadine G. Reitman, Joel B. Smith, Jeffrey A. Coe, Luke McGuire
Conceptual framework for assessing disturbance impacts on debris-flow initiation thresholds across hydroclimatic settings Conceptual framework for assessing disturbance impacts on debris-flow initiation thresholds across hydroclimatic settings
The destructive and deadly nature of debris flows has motivated research into empirical rainfall thresholds to provide situational awareness, inform early warning systems, and reduce loss of life and property. Disturbances such as wildfire and land-cover change can influence the hydrological processes of infiltration and runoff generation; in steep terrain this typically lowers empirical
Authors
Benjamin B. Mirus, Dennis M. Staley, Jason W. Kean, Joel B. Smith, Rick Wooten, Luke A. McGuire, Brian A. Ebel
Overcoming barriers to progress in seismic monitoring and characterization of debris flows and lahars Overcoming barriers to progress in seismic monitoring and characterization of debris flows and lahars
Debris flows generate seismic signals that contain valuable information about events as they unfold. Though seismic waves have been used for along-channel debris-flow and lahar monitoring systems for decades, it has proven difficult to move beyond detection to more quantitative characterizations of flow parameters and event size. This is for two primary reasons: (1) our limited...
Authors
Kate E. Allstadt, Maxime Farin, Andrew Lockhart, Sara K. McBride, Jason W. Kean, Richard M. Iverson, Matthew Logan, Joel B. Smith, Victor C. Tsai, David L. George
Thresholds for post-wildfire debris flows: Insights from the Pinal Fire, Arizona, USA 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 quantifying the rainfall intensities...
Authors
Carissa A Raymond, Luke A. McGuire, Ann M. Youberg, Dennis M. Staley, Jason W. Kean
Developing and testing physically based triggering thresholds for runoff‐generated debris flows Developing and testing physically based triggering thresholds for runoff‐generated debris flows
Runoff in steep channels is capable of transitioning into debris flows with hazardous implications for downstream communities and infrastructure, particularly in alpine landscapes with minimal vegetation and areas recently disturbed by wildfire. Here, we derive thresholds for the initiation of runoff‐generated debris flows based on critical values of dimensionless discharge and Shields...
Authors
Hui Tang, Luke A. McGuire, Francis K. Rengers, Jason W. Kean, Dennis M. Staley, Joel B. Smith
Exploring controls on debris-flow surge velocity and peak discharge at Chalk Cliffs, Colorado, USA Exploring controls on debris-flow surge velocity and peak discharge at Chalk Cliffs, Colorado, USA
We present a series of debris-flow events and use combined sensor and video data to explore how sediment concentration and triggering rainfall intensity affect the velocity and discharge of debris-flow surges generated by surface-water runoff. We analyze an initial data set of 49 surges from four debris-flow events recorded by a monitoring system at Chalk Cliffs, Colorado and compare...
Authors
Joel B. Smith, Jason W. Kean, Jeffrey A. Coe
A 4000-year history of debris flows in north-central Washington State, U.S.A.: Preliminary results from trenching and surficial geologic mapping at the Pope Creek fan A 4000-year history of debris flows in north-central Washington State, U.S.A.: Preliminary results from trenching and surficial geologic mapping at the Pope Creek fan
Long-term records of the magnitude and frequency of debris flows on fans are rare, but such records provide critical information needed for debris-flow hazard and risk assessments. This study explores the history of debris flows on a fan with seasonally inhabited cabins at Pope Creek along the Entiat River about 48 km upstream from the town of Entiat, Washington. Motivation for this...
Authors
Jeffrey A. Coe, Erin Bessette-Kirton, Stephen Slaughter, Francis K. Rengers, Trevor A. Contreras, Katherin A Michelson, Emily M. Taylor, Jason W. Kean, Kara Jacobacci, Molly A Hanson
An evaluation of debris-flow runout model accuracy and complexity in Montecito, CA: Towards a framework for regional inundation-hazard forecasting An evaluation of debris-flow runout model accuracy and complexity in Montecito, CA: Towards a framework for regional inundation-hazard forecasting
Numerous debris-flow inundation models have been applied retroactively to noteworthy events around the world. While such studies can be useful in identifying controlling factors, calibrating model parameters, and assessing future hazards in specific study areas, model parameters tailored to individual events can be difficult to apply regionally. The advancement of debris-flow modeling...
Authors
Erin Bessette-Kirton, Jason W. Kean, Jeffrey A. Coe, Francis K. Rengers, Dennis M. Staley