Geomorphology: A Red Hot Tool for Investigating Catastrophic Response to Wildfire
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Transcript of Geomorphology: A Red Hot Tool for Investigating Catastrophic Response to Wildfire
Geomorphology: A Red Hot Tool for Investigating Catastrophic
Response to Wildfire
By
Mimi Diaz
Department of Geological Sciences
GELSS 2003 Arizona State University
Outline
• The chasm between science and society
• Rodeo-Chediski Wildfire statistics
• Geologic hazards associated with wildfires
• Geomorphology defined and applied
• Expected outcomes of this project
The Chasm
• Society– Everyday people
– Immediate problems
• Science, stereotype– “Different” people
– Abstract problems
• Science, reality– Everyday people
– Everyday applications
Why a Chasm?
• Communication!– Between scientists
• Different disciplines
• Different languages
– Between scientists and politicians• Politicians/broad focus/compromise
• Scientists/narrow focus/logic over reality
– Between scientists and general public• Theory vs application
• Different scientific backgrounds
• June—July 2002: the largest wildfire in modern Arizona history
• Destroyed nearly 470 homes and burned ~500,000 acres of forest
Photo courtesy Apache-Sitgreaves National Forest
Wildfire-Induced Geologic Hazards• Floods• Mud Flows• Debris Flows• Landslides
• Los Alamos, NM, 2000
• Banks, ID, 1997• Storm King Mtn, CO,
1994 Photo courtesy Jim Scheidt, BLM
Who is involved with wildfire?
• Society– Perpetrators
– Victims
– Firefighters
– Law enforcement
– Politicians
• Science– Wildlife ecologists
– Botanists
– Pedologists
– Hydrologists
– Geomorphologists?
What is geomorphology?
• The study of nature, origin, and development of landscapes through time, especially by:– Description
– Classification
– Prediction
• Time scales:– Recent geologic time (last 10,000 years)
– Human time (immediate past, present, future)
How do wildfires affect the landscape?
• Wildfire effect– Vegetation destruction
– Soil burning
– Rock fracturing
• Landscape response– Reduced soil cohesion
– Reduced water infiltration capacity
– Reduced strength
So, what does that mean?
Rodeo-Chediski Wildfire Area, August 2002
burned watershed + steep slopes + rain = mass movement
Rodeo-Chediski Wildfire Area, August 2002
What is Mass Movement?
• Occurs when material moves downhill uniformly (as in a landslide) or chaotically (as in a debris flow)
• Material includes dirt, rocks (small and large), trees, houses, vehicles, etc.
• Initiates uphill, terminates in lower portions of basins
How can mass wasting be predicted?
Observations + Applications = Forecast
Topography
Rock type
Burn severity (soil and vegetation)
Precipitation patterns
Drainage basin characteristics
Known physics and mechanics of mass movement
Type of mass movement expected
Location of movement
An area susceptible to debris flows:
Steep topography
High burn severity
Drainages present
The Job Doesn’t End There…
• Frequently, this is the point at which science stops
• Results may be written up in a professional journal or as a thesis
• But who tells the general public??
How to Cross the Chasm
Translation
+
Circulation
=
Proper Communication
Thank You!Mimi Diaz [email protected]