A5036549244- Landslides and related hazards
- Fire effects on ecosystems
- Flood Risk Assessment and Management
- Soil erosion and sediment transport
- Hydrology and Sediment Transport Processes
- Rangeland and Wildlife Management
- Aeolian processes and effects
- Hydrology and Watershed Management Studies
- Remote Sensing and LiDAR Applications
- Cryospheric studies and observations
- Tree Root and Stability Studies
- Geology and Paleoclimatology Research
- Plant Water Relations and Carbon Dynamics
- Coastal and Marine Dynamics
- earthquake and tectonic studies
- Soil and Unsaturated Flow
- Geological formations and processes
- Meteorological Phenomena and Simulations
- Radioactive contamination and transfer
- Fire dynamics and safety research
- Archaeology and Natural History
- Geotechnical Engineering and Analysis
- Water Quality and Resources Studies
- Advanced Optical Sensing Technologies
- Seismology and Earthquake Studies
United States Geological Survey
2016-2025
Geologic Hazards Science Center
2018-2025
University of Exeter
2024
Colorado State University
2006-2024
Denver School of Nursing
2023
University of Colorado System
2014-2018
Cooperative Institute for Research in Environmental Sciences
2013-2016
University of Colorado Boulder
2014-2016
Denver Federal Center
2016
Abstract Shortly before the beginning of 2017–2018 winter rainy season, one largest fires in California (USA) history (Thomas fire) substantially increased susceptibility steep slopes Santa Barbara and Ventura Counties to debris flows. On 9 January 2018, fire was fully contained, an intense burst rain fell on portion burn area above Montecito, California. The rainfall associated runoff triggered a series flows that mobilized ∼680,000 m3 sediment (including boulders >6 m diameter) at...
Research Article| March 27, 2018 Landslides Triggered by the 14 November 2016 Mw 7.8 Kaikōura Earthquake, New Zealand C. Massey; Massey aGNS Science, P.O. Box 30‐368, Lower Hutt 5040, Zealand, c.massey@gns.cri.nz Search for other works this author on: GSW Google Scholar D. Townsend; Townsend E. Rathje; Rathje bUniversity of Texas, 110 Inner Campus Drive, Austin, Texas 78705 K. Allstadt; Allstadt cU.S. Geological Survey, 25046, DFC, MS 966, Denver, Colorado 80225‐0046 B. Lukovic; Lukovic Y....
Abstract In the semiarid Southwestern USA, wildfires are commonly followed by runoff-generated debris flows because remove vegetation and ground cover, which reduces soil infiltration capacity increases erodibility. At a study site in Southern California, we initially observed first year following fire. However, at same three years after fire, mass-wasting response to long-duration rainstorm with high rainfall intensity peaks was shallow landsliding rather than flows. Moreover, storm caused...
Abstract Debris flows are a typical hazard on steep slopes after wildfire, but unlike debris that mobilize from landslides, most postwildfire generated water runoff. The majority of existing flow modeling has focused landslide‐triggered flows. In this study we explore the potential for using process‐based rainfall‐runoff models to simulate timing and runoff‐generated in recently burned areas. Two different spatially distributed hydrologic with differing levels complexity were used: full...
Abstract Postwildfire debris flows are frequently triggered by runoff following high‐intensity rainfall, but the physical mechanisms which water‐dominated transition to poorly understood relative flow initiation from shallow landslides. In this study, we combined a numerical model with high‐resolution hydrologic and geomorphic data sets test two different hypotheses for during rainfall event that produced numerous within recently burned drainage basin. Based on simulations, large volumes of...
Abstract More than 1100 debris flows were mobilized from shallow landslides during a rainstorm 9 to 13 September 2013 in the Colorado Front Range, with vast majority initiating on sparsely vegetated, south facing terrain. To investigate physical processes responsible for observed aspect control, we made measurements of soil properties densely forested north hillslope and grassland‐dominated Range performed numerical modeling transient changes pore water pressure throughout rainstorm. Using...
Wildfire alters vegetation cover and soil hydrologic properties, substantially increasing the likelihood of debris flows in steep watersheds. Our understanding initiation mechanisms postwildfire is limited, part, by a lack direct observations measurements. In particular, there need to understand temporal variations debris‐flow following wildfire how those relate wildfire‐induced geomorphic changes. this study, we use combination situ measurements, monitoring equipment, numerical modeling...
Abstract Hazard assessment for post‐wildfire debris flows, which are common in the steep terrain of western United States, has focused on susceptibility upstream basins to generate flows. However, reducing public exposure this hazard also requires an hazards downstream areas that might be inundated during flow runout. Debris runout models widely available, but their application flows not been extensively tested. Necessary inputs these include total volume mobilized flow, properties (either...
Abstract Post‐wildfire changes to hydrologic and geomorphic systems can lead widespread sediment redistribution. Understanding how moves through a watershed is crucial for assessing hazards, developing debris flow inundation models, engineering retention solutions, quantifying the role that disturbances play in landscape evolution. In this study, we used terrestrial airborne lidar measure redistribution 2016 Fish Fire, San Gabriel Mountains southern California, USA. The areas are two...
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 hydrologic triggering conditions for as postwildfire infiltration properties evolve through time. Our approach produces time-varying rainfall intensity-duration thresholds runoff- infiltration-generated physics-based simulations that are parameterized widely available hydroclimatic, vegetation...
Abstract Wildfire‐induced changes to soil and vegetation promote runoff‐generated debris flows in steep watersheds. Postfire are most commonly observed watersheds during the first wet season following a wildfire, but it is unclear how long elevated threat of flow persists why debris‐flow potential recovering burned areas. This work quantifies rainfall intensity‐duration (ID) thresholds for initiation change with time since burning provides mechanistic explanation these changes. We...
Abstract We present observations and analysis of gully headcut erosion, which differ from previous studies in both spatial temporal detail. Using ten terrestrial laser scanning (TLS) surveys conducted over a period 3 years, we mapped erosion with centimeter‐scale detail on sub‐annual basis. Erosional change is observed through point cloud differencing, expands retreat rate by revealing the evolution morphology. Headcut are combined hydrological measurements to explore controlling factors...
Abstract We explored regional influences on debris-flow initiation throughout the Colorado Front Range (Colorado, USA) by exploiting a unique data set of more than 1100 debris flows that initiated during 5 day rainstorm in 2013. Using geospatial data, we examined influence rain, hillslope angle, aspect, and vegetation density initiation. In particular used greenness index to differentiate areas high tree from grass bare soil. The demonstrated an overwhelming propensity for south-facing...
Abstract Runoff in steep channels is capable of transitioning into debris flows with hazardous implications for downstream communities and infrastructure, particularly alpine landscapes minimal vegetation areas recently disturbed by wildfire. Here, we derive thresholds the initiation runoff‐generated based on critical values dimensionless discharge Shields stress. These are derived using a numerical model to estimate hydrodynamic conditions coinciding timing flow activity burned basin. A...
Abstract Predicting the timing of overland flow in burned watersheds can help to estimate debris‐flow and location initiation. Numerical models produce predictions, but they are limited by our knowledge appropriate model parameters. Moreover, opportunities test calibrate parameters post‐wildfire settings available data (measurements rare). In this study, we use a unique set rainfall flow‐timing extent which be generalized from an individual watershed other (0.01 km 2 >1 k m ) within area....
In the southwestern United States, post-fire debris flows commonly initiate during short bursts of intense rainfall. To date, frequency rainfall rates has not been quantified. Here, we combine an existing database debris-flow occurrences and corresponding peak storm intensities with a geospatial library recurrence interval (RI) information climate type to determine distribution estimated frequencies associated 316 observed in States. Our results indicate that majority (77%) were triggered by...
AbstractUsing observations from 688 debris flows, we analyse the hydrologic and landscape characteristics that influenced debris‐flow initiation mechanisms locations in a watershed had been partially burned by 2012 Whitewater‐Baldy Complex Fire Gila Mountains, southern New Mexico. Debris flows can initiate due to different processes. Slopes fail as discrete landslides then become fluidized move downstream (landslide initiated) or progressive bulking of sediment distributed area channelized...
Abstract Debris flows pose a significant hazard to communities in mountainous areas, and there is continued need for methods delineate zones associated with debris-flow inundation. In certain situations, such as scenarios following wildfire, where could be an abrupt increase the likelihood size of debris that necessitates rapid assessment, computational demands inundation models play role their utility. The inability efficiently determine downstream effects anticipated events remains...
Abstract. Moderate- or high-severity fires promote increases in runoff and erosion, leading to a greater likelihood of extreme geomorphic responses, including debris flows. In the first several years following fire, majority flows initiate when rapidly entrains sediment on steep slopes. From hazard perspective, it is important be able anticipate where watershed responses will dominated by rather than flood Rainfall intensity averaged over 15 min duration, I15, particular, has been identified...
Gullies are dynamic fluvial features that can be the primary driver for landscape dissection and sediment production in many settings. This research exploits a well-constrained field area near West Bijou Creek, Colorado, U.S., order to develop natural experiment which we explore gully headcut erosion rates, controls on height, morphology of longitudinal profiles. Analysis retreat using aerial photography airborne lidar imagery indicates rates correlate with square root drainage...
Abstract Erosion following a wildfire is much greater than background erosion in forests because of wildfire‐induced changes to soil erodibility and water infiltration. While many previous studies have documented post‐wildfire with point small plot‐scale measurements, the spatial distribution post‐fire patterns at watershed scale remains largely unexplored. In this study lidar surveys were collected periodically small, first‐order drainage basin over period 2 years wildfire. The site was...
Abstract Mountain watersheds recently burned by wildfire often experience greater amounts of runoff and increased rates sediment transport relative to similar unburned areas. Given the sedimentation debris flow threats caused increases in erosion, more work is needed better understand physical mechanisms responsible for observed increase environments time scale over which a heightened geomorphic response can be expected. In this study, we quantified importance different hillslope erosion...
Research Article| March 27, 2018 Improving Near‐Real‐Time Coseismic Landslide Models: Lessons Learned from the 2016 Kaikōura, New Zealand, Earthquake Kate E. Allstadt; Allstadt aU.S. Geological Survey, Geologic Hazards Science Center, P.O. Box 25046, DFC, MS 966, Denver, Colorado 80225, kallstadt@usgs.gov Search for other works by this author on: GSW Google Scholar Randall W. Jibson; Jibson Eric M. Thompson; Thompson Chris I. Massey; Massey bGNS Science, 1 Fairway Drive, Avalon 5010, 30‐368,...
Abstract Soils in post‐wildfire environments are often characterized by a low infiltration capacity with high degree of spatial heterogeneity relative to unburned areas. Debris flows frequently initiated run‐off recently burned steeplands, making it critical develop and test methods for incorporating variability into hydrologic models. We use Monte Carlo simulations generation over soil spatially heterogenous saturated hydraulic conductivity ( K s ) derive an expression aerially averaged...