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Francis Rengers

I investigate landslide and debris flow processes, primarily after wildfire.

General Research Statement:

My work leverages high-resolution topography from airborne and ground-based lidar, as well as drone-based structure-from-motion, to characterize the controls on mass movement after wildfire.  I also use modeling and field-instrumentation to characterize how wildfire creates the hydrologic and soil conditions that lead to sedimentation hazards. My work is primarily focused in the semi-arid portions of the Western United States, and I have worked on projects in Australia, New Zealand, and Sri Lanka. In addition, I serve as an adjunct professor at the Colorado School of Mines, I advise USGS post-docs, and I am currently serving on Ph.D. thesis committees at several universities.

Education:

  • Ph.D., Geology, University of Colorado, Boulder, CO. 2014. The Influence of Transient Perturbations on Landscape Evolution: Exploring Gully Erosion and Post-Wildfire Erosion.
  • M. S., Geology, Colorado State University, Fort Collins, CO. 2005.  Grain Size Trends of Gravel Bars on the Rio Chagres, Panama
  • B. S., Geology, Summa Cum Laude, West Virginia University, Morgantown, WV. 2003. Spatial Analysis of Landforms on Reclaimed Surface Mines of Monongalia County 
  • B. A., French, Summa Cum Laude, West Virginia University, Morgantown, WV. 2003

Professional Appointments: 

2016-present                        Research Geologist

2014-2016                            Mendenhall Postdoctoral Research Fellow

Staley, D.M., Kean, J.W., Rengers, F.K. 2020. The recurrence interval of post-fire debris-flow generating rainfall in the southwestern United States. Geomorphology. https://doi.org/10.1016/j.geomorph.2020.107392

Rengers, F.K., McGuire, L.A., Oakley, N.S., Tang, H., Kean, J.W., and Staley, D.M. 2020. Landslides after Wildfire: initiation, magnitude, and mobility after fire.  Landslides. https://doi.org/10.1007/s10346-020-01506-3

Rengers, F.K., Kean, J.W., Reitman, N.G., Smith, J.B., Coe, J.A., McGuire, L.A., 2020. The Influence of Frost Weathering on Debris Flow Sediment Supply in an Alpine Basin. Journal of Geophysical Research: Earth Surface 125, e2019JF005369. https://doi.org/10.1029/2019JF005369

Wall, S., Roering, J., Rengers, F.K., 2020. Runoff-initiated post-fire debris flow Western Cascades, Oregon. Landslides. https://doi.org/10.1007/s10346-020-01376-9

Rapstine, T.D., Rengers, F.K., Allstadt, K.E., Iverson, R.M., Smith, J.B., Obryk, M.K., Logan, M. Olsen, M.J. 2020. Reconstructing the velocity and deformation of a rapid landslide using multiview video. Journal of Geophysical Research: Earth Surface.  https://doi.org/10.1029/2019JF005348

Kean, Jason W., Staley, D.M., Lancaster, J.T., Rengers, F.K., Swanson, B.J., Coe, J.A., Hernandez, J.L., Sigman, A.J., Allst

Science and Products

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severely damaged, cracked road at top of debris flow

Landslide Assessments, Situational Awareness, and Event Response Research (LASER)

Landslide crises can unfold in many ways, but in all cases, responders and the public need information about what happened and what might happen next as soon as possible. The LASER project seeks to provide event-driven information products and assessments for landslide events to help guide decision-making and inform the public. The project also conducts research and development aimed towards...
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Landslide Hazards Program, Geologic Hazards Science Center
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Landslide Assessments, Situational Awareness, and Event Response Research (LASER)

Landslide crises can unfold in many ways, but in all cases, responders and the public need information about what happened and what might happen next as soon as possible. The LASER project seeks to provide event-driven information products and assessments for landslide events to help guide decision-making and inform the public. The project also conducts research and development aimed towards...
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a pile of large boulders and tree parts up against a guardrail next to a road

Columbia River Gorge Landslides

Extreme rainfall during two atmospheric river events in January 2021 and January 2022 triggered a series of debris flows in the Columbia River Gorge, Oregon. The flows had significant impacts, including multiple highway closures and one fatality. This story map highlights rainfall data and observations of debris flow deposits by the Oregon Department of Geology and Mineral Industries (DOGAMI)...
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Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center
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Columbia River Gorge Landslides

Extreme rainfall during two atmospheric river events in January 2021 and January 2022 triggered a series of debris flows in the Columbia River Gorge, Oregon. The flows had significant impacts, including multiple highway closures and one fatality. This story map highlights rainfall data and observations of debris flow deposits by the Oregon Department of Geology and Mineral Industries (DOGAMI)...
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Damaged house surrounded by rocks, trees, and mud

Cameron Peak, Colorado, Fire: Flooding and Debris Flows - July 20, 2021

On Thursday, August 13, 2020, at approximately 1:45 PM MDT, the Cameron Peak fire was reported in steep, rugged terrain 15 miles southwest of Red Feather Lakes, Colorado, near Cameron Pass. The fire spread rapidly due to extreme temperatures, strong winds, and high fuel loads. The largest wildfire in Colorado history, the Cameron Peak fire burned 845 square kilometers (sq km) on the Arapaho and...
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Natural Hazards Mission Area, Landslide Hazards Program
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Cameron Peak, Colorado, Fire: Flooding and Debris Flows - July 20, 2021

On Thursday, August 13, 2020, at approximately 1:45 PM MDT, the Cameron Peak fire was reported in steep, rugged terrain 15 miles southwest of Red Feather Lakes, Colorado, near Cameron Pass. The fire spread rapidly due to extreme temperatures, strong winds, and high fuel loads. The largest wildfire in Colorado history, the Cameron Peak fire burned 845 square kilometers (sq km) on the Arapaho and...
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mud covering highway

Glenwood Canyon, Colorado, Flooding and Debris Flows: 2021

Summer storms on the Grizzly Creek burn area have resulted in repeated flooding and debris flows that are having enormous impacts in Glenwood Canyon. This Story Map collection summarizes the June and July events.
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Natural Hazards Mission Area, Landslide Hazards Program
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Glenwood Canyon, Colorado, Flooding and Debris Flows: 2021

Summer storms on the Grizzly Creek burn area have resulted in repeated flooding and debris flows that are having enormous impacts in Glenwood Canyon. This Story Map collection summarizes the June and July events.
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topo map with shaded areas and lines following drainage channels

Bond Fire Debris Flows, California: January 25 and 28, 2021

On Wednesday, December 2, 2020 at approximately 10:15 PM PST, the Bond wildfire ignited in Orange County, California, burning partially within the Cleveland Forest, near Silverado Canyon just north of the area burned by the October 2020 Silverado fire. The fire burned 27 square kilometers (sq km) prior to containment on December 10, 2020 (CalFire). Fuels were primarily chaparral, brush, and tall...
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Natural Hazards Mission Area, Landslide Hazards Program
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Bond Fire Debris Flows, California: January 25 and 28, 2021

On Wednesday, December 2, 2020 at approximately 10:15 PM PST, the Bond wildfire ignited in Orange County, California, burning partially within the Cleveland Forest, near Silverado Canyon just north of the area burned by the October 2020 Silverado fire. The fire burned 27 square kilometers (sq km) prior to containment on December 10, 2020 (CalFire). Fuels were primarily chaparral, brush, and tall...
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leaning trees and boulders on ground

Northern and Central California Debris Flows - January 2021

An atmospheric river (AR) moved into California late on the evening of January 26, 2021, bringing intermittent heavy rainfall that resulted in flooding, debris flows, and heavy snowfall at high elevations.
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Natural Hazards Mission Area, Landslide Hazards Program
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Northern and Central California Debris Flows - January 2021

An atmospheric river (AR) moved into California late on the evening of January 26, 2021, bringing intermittent heavy rainfall that resulted in flooding, debris flows, and heavy snowfall at high elevations.
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people in a forest with large rocks and boulders strewn around

Tadpole Fire Debris Flows, New Mexico: July and September 2020

On Saturday, June 6, 2020 at approximately 1:45 PM MDT, the Tadpole wildfire ignited in the Gila National Forest, approximately 19 kilometers (km) north of Silver City, Grant County, New Mexico. The fire burned 45 square kilometers prior to containment in early July, 2020 (Inciweb). Fuels were primarily timber with grass understory, brush, and chaparral. The Brush, Bringham, and Bighorn fires in...
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Natural Hazards Mission Area, Landslide Hazards Program
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Tadpole Fire Debris Flows, New Mexico: July and September 2020

On Saturday, June 6, 2020 at approximately 1:45 PM MDT, the Tadpole wildfire ignited in the Gila National Forest, approximately 19 kilometers (km) north of Silver City, Grant County, New Mexico. The fire burned 45 square kilometers prior to containment in early July, 2020 (Inciweb). Fuels were primarily timber with grass understory, brush, and chaparral. The Brush, Bringham, and Bighorn fires in...
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person standing in dry debris-flow bed with rocks and small boulders

Woodbury Fire, Arizona Debris Flows - September 2019

On Saturday, June 8, 2019 at approximately 1:30 PM MST, the Woodbury wildfire ignited approximately 8 kilometers (km) northwest of Superior, Arizona. The 7th largest wildfire in Arizona’s recorded history, the fire burned 501 km2 prior to containment on July 15, 2019. The fire occurred within the Superstition Wilderness of the Tonto National Forest. The wilderness area extends from the...
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Natural Hazards Mission Area, Landslide Hazards Program
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Woodbury Fire, Arizona Debris Flows - September 2019

On Saturday, June 8, 2019 at approximately 1:30 PM MST, the Woodbury wildfire ignited approximately 8 kilometers (km) northwest of Superior, Arizona. The 7th largest wildfire in Arizona’s recorded history, the fire burned 501 km2 prior to containment on July 15, 2019. The fire occurred within the Superstition Wilderness of the Tonto National Forest. The wilderness area extends from the...
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burned mountain slope with charred trees, and two people near a landslide monitoring instrument

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.
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Natural Hazards Mission Area, Landslide Hazards Program
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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.
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USGS science for a changing world logo

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 approa
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Community for Data Integration (CDI)
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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 approa
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mud, large boulders, and overturned FTE next to house

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...
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Natural Hazards Mission Area, Landslide Hazards Program
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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...
Learn More
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USGS science for a changing world logo

Exploiting high-resolution topography for advancing the understanding of mass and energy transfer across landscapes: Opportunities, challenges, and needs

One of the grand challenges of Earth Surface Science and Natural Resource Management lies in the prediction of mass and energy transfer for large watersheds and landscapes. High resolution topography (lidar) datasets show potential to significantly advance our understanding of hydrologic and geomorphic processes controlling mass and energy transfer because they represent features at the appropriat
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John Wesley Powell Center for Analysis and Synthesis
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Exploiting high-resolution topography for advancing the understanding of mass and energy transfer across landscapes: Opportunities, challenges, and needs

One of the grand challenges of Earth Surface Science and Natural Resource Management lies in the prediction of mass and energy transfer for large watersheds and landscapes. High resolution topography (lidar) datasets show potential to significantly advance our understanding of hydrologic and geomorphic processes controlling mass and energy transfer because they represent features at the appropriat
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Filter Total Items: 16

UAV imagery and digital elevation data for the debris slide in Chaos Canyon, 28 June 2022, Rocky Mountain National Park, Colorado.

This dataset contains a point cloud (HalletPeak_PointCloud.las), digital elevation model (HalletPeak_DEM.tif), and orthoimagery (HalletPeak_Ortho.tif) of a debris slide originating on the southeast flank of Hallett Peak and sliding into Upper Chaos Canyon in Rocky Mountain National Park, Colorado, USA. The slide occurred on 28 June 2022, and imagery was obtained on 15 July 2022. These products wer
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Geologic Hazards Science Center

Airborne Lidar Data (2016 and 2021) Capturing Debris Flow Erosion and Deposition after the Grizzly Creek Fire in Glenwood Canyon, Colorado

This dataset contains lidar digital elevation models (DEMs). The lidar data were collected before (2016) and after (2021) the Grizzly Creek Fire, which occurred in 2020. The 2016 lidar was collected during a series of flights between 10 June and 7 October 2016. The 2021 lidar flight was conducted in full on 24 August 2021. The files are named with the following convention: Vendor_Year_Resolution_m
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Geologic Hazards Science Center

Field-verified inventory of postfire hydrologic response for the 2020 CZU Lightning Complex, River, Camel, and Dolan Fires following a 26-29 January 2021 atmospheric river storm sequence

This data release is a field-verified inventory of postfire hydrologic response for the 2020 CZU (San Mateo–Santa Cruz Unit) Lightning Complex, River Fire, Camel Fire, and Dolan Fire following a 26-29 January 2021 atmospheric river storm sequence. Postfire hydrologic response types include a) no response, b) minor response, and c) major response. A “minor” response was deemed capable of impairing
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Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center

Tadpole Fire Field Measurements following the 8 September 2020 Debris Flow, Gila National Forest, NM

This data release contains data summarizing observations within and adjacent to the Tadpole Fire, which burned from 6 June to 4 July 2020 in the Gila National Forest, NM. This monitoring data were focused on debris flows triggered on 8 September 2020 in four drainage basins (TAD1, TAD2, TAD3, and TAD4). Rainfall data (1a_rain_geophones.csv) are provided in a comma-separated value (CSV) file. The
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Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center

Reclassified lidar point cloud data from 2016 LARIAC and 2019 NCALM collections covering part of the Woolsey wildfire near Malibu, California

These lidar data are derived from two airborne lidar surveys: a 2016 Los Angeles Region Imagery Acquisition Consortium (LARIAC) survey, and a 2019 National Center for Airborne Laser Mapping (NCALM) survey. These data were reclassified in order to improve the classification of ground points, and to make the classification of both datasets as consistent as possible. The NCALM data had their position
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Earthquake Hazards Program, Earthquake Science Center

Post-wildfire debris-flow monitoring data, 2019 Woodbury Fire, Superstition Mountains, Arizona, USA November 2019 to February 2020

This data release contains data summarizing observations within and adjacent to the Woodbury Fire, which burned from 8 June to 15 July 2019. In particular, this monitoring data was focused on debris flows in burned and unburned areas. Rainfall data (1_Woodbury_Rainfall.zip) are contained in comma-separated value (CSV) files named ?Wdby_Rainfall? appended with the names of 3 rain gages: B2, B6,
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Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center

Soil moisture monitoring following the 2009 Station Fire, California, USA, 2016-2019

This data release includes 2016-2019 soil moisture timeseries for two drainage basins ("Arroyo Seco" and "Dunsmore Canyon") that burned during the 2009 Station Fire in Los Angeles County, California, USA. The Arroyo Seco (0.01 km2) and Dunsmore Canyon (0.5 km2) drainages include two soil pits, one located near the drainage divide and another near the basin outlet. Following the naming convention e
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Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center

Data supporting an analysis of the recurrence interval of post-fire debris-flow generating rainfall in the southwestern United States

This data release supports the analysis of the recurrence interval of post-fire debris-flow generating rainfall in the southwestern United States. We define the recurrence interval of the peak 15-, 30-, and 60-minute rainfall intensities for 316 observations of post-fire debris-flow occurrence in 18 burn areas, 5 U.S. states, and 7 climate types. These data support the analysis described in Staley
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Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center

Inventory of landslides triggered by rainfall on 16-17 January 2019, Los Angeles County, CA

This dataset contains 286 landslide polygons mapped after a rainstorm on 16-17 January 2019. The majority of the landslides are located in the burn areas of the 2016 San Gabriel Complex fire, the 2014 Colby fire, and the 2009 Morris fire. A smaller number of additional landslides were located in nearby unburned areas. More information about the burn perimeters associated with this inventory and t
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Landslide Hazards Program

Lidar data for natural release experiment at the USGS Debris Flow Flume 17 May 2017

Lidar data were collected on 17 May 2017 at the USGS debris-flow flume (44.215, -122.254) to monitor the movement of a constructed landslide experiment. A static prism of sediment was emplaced behind a retaining wall at the top of the flume. Water was added via sprinklers to the surface and also via pipes to the subsurface, in order to saturate the sediment mass. The sediment mass eventually fa
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Earthquake Hazards Program, Landslide Hazards Program, Geologic Hazards Science Center

Lidar data for gate release experiment at the USGS Debris-Flow Flume 24 and 25 May 2017

Lidar data was collected on 24 and 25 May 2017 at the USGS debris-flow flume to monitor two gate-release debris flow experiments. A static prism of sediment was emplaced behind a gate at the top of the flume. Water was added via sprinklers to the surface and also via pipes to the subsurface, in order to saturate the sediment mass. The sediment mass moved down the flume as a debris flow when the ga
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Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center

Chalk Cliffs Channel Surveys derived from Structure-from-Motion

This data release contains two point clouds derived from structure-from-motion photogrammetry. The first survey was conducted on 10 September 2015 and the second survey was conducted on 1 June 2016. Each survey was designed to capture a 35-meter channel reach using digital photos (1187 photos were taken in the first survey and 1085 photos were taken in the second survey). Twenty-five bolts were dr
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Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center
black and white image of mountain with text Virtual Field Excursion to Glenwood Canyon, Colorado: and the post-fire debris flows from the 2020 Grizzly Creek Fire
Virtual Field Excursion to Glenwood Canyon, Colorado: and the post-fire debris flows from the 2020 Grizzly Creek Fire
black and white image of mountain with text

Virtual Field Excursion to Glenwood Canyon, Colorado: and the post-fire debris flows from the 2020 Grizzly Creek Fire

Virtual Field Excursion to Glenwood Canyon, Colorado: and the post-fire debris flows from the 2020 Grizzly Creek Fire

This video serves as a virtual fieldtrip to document the debris flow activity following the Grizzly Creek Fire in the Glenwood Canyon, CO, USA. The Grizzly Creek Fire initiated in August 2020, and widespread destructive debris flow activity followed the during the summer of 2021.

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Landslide Hazards Program, Geologic Hazards Science Center
black and white image of mountain with text

Virtual Field Excursion to Glenwood Canyon, Colorado: and the post-fire debris flows from the 2020 Grizzly Creek Fire

Virtual Field Excursion to Glenwood Canyon, Colorado: and the post-fire debris flows from the 2020 Grizzly Creek Fire

This video serves as a virtual fieldtrip to document the debris flow activity following the Grizzly Creek Fire in the Glenwood Canyon, CO, USA. The Grizzly Creek Fire initiated in August 2020, and widespread destructive debris flow activity followed the during the summer of 2021.

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Landslide Hazards Program, Geologic Hazards Science Center
rocks and trees on hillside during rainstorm Calwood Fire, Heil Ranch post-fire debris-flow monitoring station, July 31, 2021
Calwood Fire, Heil Ranch post-fire debris-flow monitoring station, July 31, 2021
rocks and trees on hillside during rainstorm

Calwood Fire, Heil Ranch post-fire debris-flow monitoring station, July 31, 2021

Calwood Fire, Heil Ranch post-fire debris-flow monitoring station, July 31, 2021

Calwood burn area, Heil Ranch post-fire debris-flow monitoring station video footage from rainstorm on July 31, 2021 from 14:07 MDT to 14:13:11 MDT.

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Landslide Hazards, Geologic Hazards Science Center
rocks and trees on hillside during rainstorm

Calwood Fire, Heil Ranch post-fire debris-flow monitoring station, July 31, 2021

Calwood Fire, Heil Ranch post-fire debris-flow monitoring station, July 31, 2021

Calwood burn area, Heil Ranch post-fire debris-flow monitoring station video footage from rainstorm on July 31, 2021 from 14:07 MDT to 14:13:11 MDT.

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Landslide Hazards, Geologic Hazards Science Center
rocks and trees on hillside during rainstorm Calwood Fire, Calwood post-fire debris-flow monitoring station, July 31, 2021
Calwood Fire, Calwood post-fire debris-flow monitoring station, July 31, 2021
rocks and trees on hillside during rainstorm

Calwood Fire, Calwood post-fire debris-flow monitoring station, July 31, 2021

Calwood Fire, Calwood post-fire debris-flow monitoring station, July 31, 2021

Calwood burn area, Calwood post-fire debris-flow monitoring station video footage from rainstorm on July 31, 2021 from 14:06 MDT to 14:13:05 MDT.

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Landslide Hazards, Geologic Hazards Science Center
rocks and trees on hillside during rainstorm

Calwood Fire, Calwood post-fire debris-flow monitoring station, July 31, 2021

Calwood Fire, Calwood post-fire debris-flow monitoring station, July 31, 2021

Calwood burn area, Calwood post-fire debris-flow monitoring station video footage from rainstorm on July 31, 2021 from 14:06 MDT to 14:13:05 MDT.

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Landslide Hazards, Geologic Hazards Science Center
Filter Total Items: 54

Post-wildfire debris flows

Post-wildfire debris flows pose severe hazards to communities and infrastructure near and within recently burned mountainous terrain. Intense heat of wildfires changes the runoff characteristics of a watershed by combusting the vegetative canopy, litter, and duff, introducing ash into the soil and creating water repellant soils. Following wildfire, rainfall on bare ground is less able to infiltrat
Authors
Joseph Gartner, Jason W. Kean, Francis K. Rengers, Scott W. McCoy, Nina S. Oakley, Gary J. Sheridan

The 2022 Chaos Canyon landslide in Colorado: Insights revealed by seismic analysis, field investigations, and remote sensing

An unusual, high-alpine, rapid debris slide originating in ice-rich debris occurred on June 28, 2022, at 16:33:16 MDT at the head of Chaos Canyon, a formerly glacier-covered valley in Rocky Mountain National Park, CO, USA. In this study, we integrate eyewitness videos and seismic records of the event with meteorological data, field observations, pre- and post-event satellite imagery, and uncrewed
Authors
Kate E. Allstadt, Jeffrey A. Coe, Elaine Collins, Francis K. Rengers, Anne Mangeney, Scott M. Esser, Jana Pursley, William L. Yeck, John Bellini, Lance R. Brady
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Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center

Bedrock erosion by debris flows at Chalk Cliffs, Colorado, USA: Implications for bedrock channel evolution

Debris flow erosion into bedrock helps to set the pace of mountain denudation, but there are few empirical observations of this process. We studied the effects of debris flows on bedrock erosion using Structure-From-Motion photogrammetry and multiple real-time monitoring measurements. We found that the distribution of bedrock erosion across the channel cross-section could be generalized as an expo
Authors
Francis K. Rengers, Jason W. Kean, Jeffrey A. Coe, Megan Hanson, Joel Smith
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Natural Hazards Mission Area, Geologic Hazards Science Center

Forecasting the inundation of postfire debris flows

In the semi-arid regions of the western United States, postfire debris flows are typically runoff generated. The U.S. Geological Survey has been studying the mechanisms of postfire debris-flow initiation for multiple decades to generate operational models for forecasting the timing, location, and magnitude of postfire debris flows. Here we discuss challenges and progress for extending operational
Authors
Katherine R. Barnhart, Ryan P Jones, David L. George, Francis K. Rengers, Jason W. Kean
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Natural Hazards Mission Area, Volcano Hazards Program, Geologic Hazards Science Center, Volcano Science Center

Postfire hydrologic response along the central California (USA) coast: Insights for the emergency assessment of postfire debris-flow hazards

The steep, tectonically active terrain along the Central California (USA) coast is well known to produce deadly and destructive debris flows. However, the extent to which fire affects debris-flow susceptibility in this region is an open question. We documented the occurrence of postfire debris floods and flows following the landfall of a storm that delivered intense rainfall across multiple burn a
Authors
Matthew A. Thomas, Jason W. Kean, Scott W. McCoy, Donald N. Lindsay, Jaime Kostelnik, David B. Cavagnaro, Francis K. Rengers, Amy E. East, Jonathan Schwartz, Douglas P. Smith, Brian D. Collins
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Natural Hazards Mission Area, Geologic Hazards Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Pacific Coastal and Marine Science Center

Importance of subsurface water for hydrological response during storms in a post-wildfire bedrock landscape

Wildfire alters the hydrologic cycle, with important implications for water supply and hazards including flooding and debris flows. In this study we use a combination of electrical resistivity and stable water isotope analyses to investigate the hydrologic response during storms in three catchments: one unburned and two burned during the 2020 Bobcat Fire in the San Gabriel Mountains, California, U
Authors
Abra Atwood, Madeline Hille, Marin Clark, Francis K. Rengers, Dimitrios Ntarlagiannis, Kirk Townsend, A. Joshua West
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Natural Hazards Mission Area, Geologic Hazards Science Center

The influence of large woody debris on post-wildfire debris flow sediment storage

Debris flows transport large quantities of water and granular material, such as sediment and wood, and this mixture can have devastating impacts on life and infrastructure. The proportion of large woody debris (LWD) incorporated into debris flows can be enhanced in forested areas recently burned by wildfire, because wood recruitment into channels accelerates in burned forests. In this study, we ex
Authors
Francis K. Rengers, Luke A. McGuire, Katherine R. Barnhart, Ann Youberg, Daniel Cadol, Alexander Gorr, Olivia Joan Andrea Khoury Hoch, Rebecca Beers, Jason W. Kean
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Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center

Guidance for parameterizing post-fire hydrologic models with in situ infiltration measurements

Wildfire can alter soil-hydraulic properties, often resulting in an increased prevalence of infiltration-excess overland flow and greater potential for debris-flow hazards. Mini disk tension infiltrometers (MDIs) can be used to estimate soil hydraulic properties, such as field-saturated hydraulic conductivity (Kfs) and wetting front potential (Hf), and their spatial variability following wildfire.
Authors
T. Liu, Luke A. McGuire, Ann Youberg, Alexander N. Gorr, Francis K. Rengers
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Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center

A review of common natural disasters as analogs for asteroid impact effects and cascading hazards

Modern civilization has no collective experience with possible wide-ranging effects from a medium-sized asteroid impactor. Currently, modeling efforts that predict initial effects from a meteor impact or airburst provide needed information for initial preparation and evacuation plans, but longer-term cascading hazards are not typically considered. However, more common natural disasters, such as vo
Authors
Timothy N. Titus, D. G. Robertson, Joel B. Sankey, Larry G. Mastin, Francis K. Rengers
By
Ecosystems Mission Area, Natural Hazards Mission Area, Volcano Hazards Program, Astrogeology Science Center, Geologic Hazards Science Center, Southwest Biological Science Center, Volcano Science Center

Simulating debris flow and levee formation in the 2D shallow flow model D-Claw: Channelized and unconfined flow

Debris flow runout poses a hazard to life and infrastructure. The expansion of human population into mountainous areas and onto alluvial fans increases the need to predict and mitigate debris flow runout hazards. Debris flows on unconfined alluvial fans can exhibit spontaneous self-channelization through levee formation that reduces lateral spreading and extends runout distances compared to unchan
Authors
Ryan P. Jones, Francis K. Rengers, Katherine R. Barnhart, David L. George, Dennis M. Staley, Jason W. Kean
By
Natural Hazards Mission Area, Science Synthesis, Analysis and Research Program, Landslide Hazards Program, Volcano Hazards Program, Geologic Hazards Science Center, Volcano Science Center, Advanced Research Computing (ARC)

A progressive flow-routing model for rapid assessment of debris-flow inundation

Debris flows pose a significant hazard to communities in mountainous areas, and there is a continued need for methods to delineate hazard zones associated with debris-flow inundation. In certain situations, such as scenarios following wildfire, where there could be an abrupt increase in the likelihood and size of debris flows that necessitates a rapid hazard assessment, the computational demands o
Authors
Alexander Gorr, Luke A. McGuire, Ann Youberg, Francis K. Rengers
By
Natural Hazards Mission Area, Geologic Hazards Science Center

Multi-model comparison of computed debris flow runout for the 9 January 2018 Montecito, California post-wildfire event

Hazard assessment for post-wildfire debris flows, which are common in the steep terrain of the western United States, has focused on the susceptibility of upstream basins to generate debris flows. However, reducing public exposure to this hazard also requires an assessment of hazards in downstream areas that might be inundated during debris flow runout. Debris flow runout models are widely availab
Authors
Katherine R. Barnhart, Ryan P. Jones, David L. George, Brian W. McArdell, Francis K. Rengers, Dennis M. Staley, Jason W. Kean
By
Natural Hazards Mission Area, Landslide Hazards Program, Volcano Hazards Program, Geologic Hazards Science Center, Volcano Science Center, Supplemental Appropriations for Disaster Recovery Activities

Non-USGS Publications**

​​​​​​​Rengers, F., Lunacek, M., and Tucker, G. 2016. Application of an Evolutionary Algorithm for Parameter Optimization in a Gully Erosion Model, Environmental Modelling & Software. 80, 297-305. doi:10.1016/j.envsoft.2016.02.033
Rengers, F. and Tucker G. 2015. The evolution of gully headcut morphology: a case study using terrestrial laser scanning and hydrological monitoring. Earth Surface Processes and Landforms. doi: 10.1002/esp.3721
Ebel, B., Rengers, F., Tucker, G. 2015. Aspect-dependent soil saturation and insight into debris-flow initiation during extreme rainfall in the Colorado Front Range. Geology. 43, 8, p. 659-652. doi: 10.1130/G36741.1
​​​​​​​Rengers, F. and Tucker, G. 2014. Analysis and modeling of gully headcut dynamics, North American high plains. Journal of Geophysical Research: Earth Surface. 119, doi:10.1002/2013JF002962.
​​​​​​​Rengers, F. and Tucker, G. 2013. Processes and rates of headcut migration in eastern Colorado gullies: West Bijou Creek field trip guide. Geological Society of America Field Guide 33.
​​​​​​​Rengers, F. and Wohl, E. 2006. Trends of grain sizes on gravel bars in the Rio Chagres, Panama. Geomorphology. 83, 3-4, p. 282-293.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Columbia River Gorge Landslides

Extreme rainfall during two atmospheric river events in January 2021 and January 2022 triggered a series of debris flows in the Columbia River Gorge, Oregon. The flows had significant impacts, including multiple highway closures and one fatality.  This story map highlights rainfall data and observations of debris flow deposits by the Oregon Department of Geology and Mineral Industries (DOGAMI).

By
Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center

Central California Coast Debris Flows - January 2021

An atmospheric river (AR) moved into California late on the evening of January 26, 2021, bringing intermittent heavy rainfall that resulted in flooding, debris flows, and heavy snowfall at high elevations.

By
Natural Hazards Mission Area, Landslide Hazards Program, Geologic Hazards Science Center

FlowAlert

A software designed to provide situational awareness on rainfall intensities relevant to potential runoff-generated debris flows in recently burned areas.
By
Geologic Hazards Science Center
Columbia River Gorge Landslides - New Interactive Geonarrative

Columbia River Gorge Landslides - New Interactive Geonarrative

Extreme rainfall during two atmospheric river events in January 2021 and January 2022 triggered a series of debris flows in the Columbia River Gorge...

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Bond Fire Debris Flows, California: January 25 and 28, 2021

Bond Fire Debris Flows, California: January 25 and 28, 2021

A new geonarrative (Esri Story Map) summarizes the debris flows that were caused by a rainstorm following the Bond Fire in California.

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