1. Evaluating Increased Erosion Potential due to Wildfires
Brian Drake
CE394K – Fall 2005
Term Project Presentation

2. Study Area

3. Cedar Wildfire Duration: 10/25/03 – 11/3/03 Size = 280,000 acres
2,232 homes destroyed
15 human deaths
Suppression Cost: >$31 Mil

4. Major Factors Affecting Soil Losses
Vegetative Cover
Soil Characteristics
Topography
Intensity of Storms

5. Modeling Erosion USDA Universal Soil Loss Equation (USLE)
A = R∙K∙LS∙C∙P
A = Soil loss per unit area
R = Rainfall-Runoff Erosivity
K = Soil Erodibility
LS = Slope Length/Steepness Factor
C = Land Cover Factor
P = Conservation Practice Factor

6. Rainfall-Runoff Erosivity (R)
Reflects rainfall intensity and storm energy

7. Soil Erodibility (K)
Represents susceptibility
of soil to erosion

8. Slope Length/Steepness (LS)
LS = (a/22.13)0.4 (s/0.0896)1.3
DEM

9. Land Cover Factor (C)
Ratio of soil loss based on vegetative cover

10. Conservation Practice Factor (P)
Reflects impact of erosion-reduction practices

11. Total Sediment Potential (A)
Aave = 30.7 ton/acre/yr
Aave = 1,295 ton/acre/yr

12. Remaining Tasks Adjustments to current pre-fire calculation
Check for unit consistency
Search for more representative R-Factor
Ensure that LS value is accurate
Modify factors to model post-fire conditions
Increase C-Factor

13. Resources DEM: http://seamless.usgs.gov/
NHD:
USDA Soils:
Fire Info:

14. Questions?