Predicting locations of post-fire debris-flow erosion in the San Gabriel Mountains of southern California

2015 ◽  
Vol 77 (2) ◽  
pp. 1305-1321 ◽  
Author(s):  
J. E. Gartner ◽  
P. M. Santi ◽  
S. H. Cannon
Keyword(s):  
Debris Flow ◽  
Southern California ◽  
San Gabriel Mountains ◽  
Fire Debris

Time Since Burning and Rainfall Characteristics Impact Post-Fire Debris-Flow Initiation and Magnitude

2021 ◽  
Vol 27 (1) ◽  
pp. 43-56
Author(s):  
Luke A. McGuire ◽  
Francis K. Rengers ◽  
Nina Oakley ◽  
Jason W. Kean ◽  
Dennis M. Staley ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Debris Flow ◽  
Debris Flows ◽  
Numerical Models ◽  
Ground Cover ◽  
Temporal Changes ◽  
Infiltration Capacity ◽  
Rainfall Characteristics ◽  
San Gabriel Mountains ◽  
Fire Debris

ABSTRACT 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 in the year immediately following wildfire, but temporal changes in the likelihood and magnitude of debris flows following wildfire are not well constrained. In this study, we combine measurements of soil-hydraulic properties with vegetation survey data and numerical modeling to understand how debris-flow threats are likely to change in steep, burned watersheds during the first 3 years of recovery. We focus on documenting recovery following the 2016 Fish Fire in the San Gabriel Mountains, California, and demonstrate how a numerical model can be used to predict temporal changes in debris-flow properties and initiation thresholds. Numerical modeling suggests that the 15-minute intensity-duration (ID) threshold for debris flows in post-fire year 1 can vary from 15 to 30 mm/hr, depending on how rainfall is temporally distributed within a storm. Simulations further demonstrate that expected debris-flow volumes would be reduced by more than a factor of three following 1 year of recovery and that the 15-minute rainfall ID threshold would increase from 15 to 30 mm/hr to greater than 60 mm/hr by post-fire year 3. These results provide constraints on debris-flow thresholds within the San Gabriel Mountains and highlight the importance of considering local rainfall characteristics when using numerical models to assess debris-flow and flood potential.

scholarly journals Emergency assessment of post-fire debris-flow hazards for the 2013 Powerhouse fire, southern California

2013 ◽  
Author(s):  
Dennis M. Staley ◽  
Gregory M. Smoczyk ◽  
Ryan R. Reeves
Keyword(s):  
Debris Flow ◽  
Southern California ◽  
Fire Debris

scholarly journals Emergency assessment of post-fire debris-flow hazards for the 2013 Mountain fire, southern California

2013 ◽  
Author(s):  
Dennis M. Staley ◽  
Joseph E. Gartner ◽  
Greg M. Smoczyk ◽  
Ryan R. Reeves
Keyword(s):  
Debris Flow ◽  
Southern California ◽  
Fire Debris

Emergency Assessment of Postfire Debris-Flow Hazards for the 2009 Station Fire, San Gabriel Mountains, Southern California

2009 ◽  
Author(s):  
Susan H. Cannon ◽  
Joseph E. Gartner ◽  
Michael G. Rupert ◽  
John A. Michael ◽  
Dennis M. Staley ◽  
...  
Keyword(s):  
Debris Flow ◽  
Southern California ◽  
San Gabriel Mountains

EMERGENCY ASSESSMENT OF POST FIRE DEBRIS FLOW AND FLOODING HAZARDS, 2015 VALLEY AND BUTTE FIRES, CALIFORNIA

2016 ◽  
Author(s):  
Patrick K. Brand ◽  
◽  
David L. Longstreth ◽  
Jeremy T. Lancaster ◽  
William R. Short
Keyword(s):  
Debris Flow ◽  
Flooding Hazards ◽  
Fire Debris

DISTINGUISHING POST-FIRE DEBRIS FLOW EROSIONAL AND DEPOSITIONAL ZONES IN A BURNED WATERSHED

2019 ◽  
Author(s):  
Francis K. Rengers ◽  
◽  
Jason W. Kean ◽  
Dennis M. Staley ◽  
Luke McGuire
Keyword(s):  
Debris Flow ◽  
Fire Debris

Observations and Analyses of the 9 January 2018 Debris-Flow Disaster, Santa Barbara County, California

2021 ◽  
Vol 27 (1) ◽  
pp. 3-27
Author(s):  
Jeremy T. Lancaster ◽  
Brian J. Swanson ◽  
Stefani G. Lukashov ◽  
Nina S. Oakley ◽  
Jacob B. Lee ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Extreme Rainfall ◽  
Atmospheric Conditions ◽  
Santa Barbara ◽  
Debris Removal ◽  
Fire Debris ◽  
Santa Barbara County ◽  
Coastal Land

ABSTRACT The post–Thomas Fire debris flows of 9 January 2018 killed 23 people, damaged 558 structures, and caused severe damage to infrastructure in Montecito and Carpinteria, CA. U.S. Highway 101 was closed for 13 days, significantly impacting transportation and commerce in the region. A narrow cold frontal rain band generated extreme rainfall rates within the western burn area, triggering runoff-driven debris flows that inundated 5.6 km2 of coastal land in eastern Santa Barbara County. Collectively, this series of debris flows is comparable in magnitude to the largest documented post-fire debris flows in the state and cost over a billion dollars in debris removal and damages to homes and infrastructure. This study summarizes observations and analyses on the extent and magnitude of inundation areas, debris-flow velocity and volume, and sources of debris-flow material on the south flank of the Santa Ynez Mountains. Additionally, we describe the atmospheric conditions that generated intense rainfall and use precipitation data to compare debris-flow source areas with spatially associated peak 15 minute rainfall amounts. We then couple the physical characterization of the event with a compilation of debris-flow damages to summarize economic impacts.

Sign in / Sign up

Export Citation Format

Share Document