1. CE 513

2. Erosion in the Fall Creek Watershed Rick Faber

3. Erosion in the Fall Creek Watershed following the Clark Fire: Implications for the Hehe Timbersale  Clark Fire destroyed 5000 acres of undisturbed forest land in late 2003  Fall Creek is home to genetically diverse population of anadromous fish  Current proposals are for a 2500 acre timber sale in the neighboring Hehe Creek basin.

6. The universal soil loss equation is: A = R K L S C P  A is soil loss (tons/acre/year)  R is the rainfall/runoff erosivity factor  K is the soil erodibility factor (tons/acre/year)  L is the slope length factor  S is the slope steepness factor  C is the cover management factor  P is the support practice factor

7. Isoerodent Map of Oregon R = 50

8. K-factor from STATSGO soil coverage from the USDA.

9. L & S: Length & Steepness Now combined and expressed as a single factor. (Moore and Burch 1986) Spatial AnalystArcHydro

11. C-Factor Land Cover TypeC-Factor Agriculture0.09 Developed0.24 Disturbed0.24 Forest0.004 Grasslands0.06 Open Water0.00 Riparian0.004 Unvegetated0.24 Woodland 0.004 LARSE DATA

12. C-Factor Rasters

13. Calculate the Erosion

14. Soil Erosion

15. The loss of one inch of soil due to erosion is equivalent to 150 tons of soil per acre. Mean Soil Loss for Fall Creek Watershed

16. Limitations  Sedimentation vs erosion  Truncate the Flow accumulation grid for LS factor  Land cover & time  Systematic error?