1. C THE ROLE OF DEBRIS FLOWS IN LONG TERM DENUDATION AND LANDSCAPE EVOLUTION OF THE CENTRAL APPALACHIANS L. Scott Eaton, Ph.D. Department of Geology and Environmental Science James Madison University

2. Death Valley, CA

4. ~ 140 fatalities

7. C Blue Ridge Mountains, VA Rapidan Storm, June 1995

8. 775 mm

13. Research Question: In the Appalachians, are debris flows a significant process in the transportation of sediment from mountainous terrain to the floodplains?

14. What is the frequency of debris flows? What is the frequency of debris flows? How much sediment is transported during an event? How much sediment is transported during an event? What are the long term erosion (denudation)rates in the central Appalachians? What are the long term erosion (denudation)rates in the central Appalachians?

15. frequency of debris flows

17. DEBRIS FLOW FREQUENCY IN THE RAPIDAN BASIN from Eaton and others, 2003

18. Sediment Transport and Denudation

19. 0.398 km 2

21. BeforeAfter ?? ?

22. 13, 364 m 3 0.398 km 2

23. Volume = 13, 364 m 3 Area 0.398 km 2 or 398,000 m 2 = 0.034 m = 3.4 cm

24. Summary of Basin Denudation of Blue Ridge Systems Event Basin Basin Area (km 2 ) Volume of Sediment Eroded (m 3 ) Mean Basin Denuda- tion (cm) Hurricane Camille Willis Cove 4.08173,4884.25 Hurricane Camille Ginseng Hollow 1.7588,7275.07 Hurricane Camille Polly Wright Cove 2.4787,7073.55 Rapidan Flood Jenkins Hollow 0.39813,3643.36 Rapidan Flood Teal Hollow0.1232,4922.03

26. Hurricane Camille Rapidan Storm

27. A Model of Appalachian Landscape Evolution

31. BEFORE…..

32. AFTER…..

33. HIGH “M” LOW (f) LOW “M” HIGH (f)