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