1 / 21

Channel Morphology of Red Canyon Wash

Channel Morphology of Red Canyon Wash. Gregory Indivero 31 October 2011. Research Questions. What discharge (cfs) is required to entrain the D 84 (84 th percentile of sediment size distribution) in Red Canyon Wash?

oriana
Download Presentation

Channel Morphology of Red Canyon Wash

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Channel Morphology ofRed Canyon Wash Gregory Indivero 31 October 2011

  2. Research Questions • What discharge (cfs) is required to entrain the D84 (84th percentile of sediment size distribution) in Red Canyon Wash? • What discharge was required to deposit observed flood debris from August 16, 2010 flood?

  3. Location of Red Canyon • Red & Columbus Canyons • Un-gauged, Ephemeral Wash • 5th Largest Drainage of CNM

  4. Satellite Photograph Red Canyon Wash Study Reach Red Canyon Columbus Canyon No Thoroughfare Canyon

  5. Specific Study Reach Site • Fairly Straight Alluvial Channel • 300 Feet Long • ≅ 20 Feet Wide

  6. Methods • Establish Reach & Cross Sections • Survey Thalweg, Flood Debris & Cross Sections • Conduct a Pebble Count at Cross Sections • Create Grain Size Distribution Plots • Solve Shields Equation for Critical Shear Stress, τc • Model Channel With HEC-RAS • -Fluctuate Discharge In Channel Until τc Is Achieved • -Fluctuate Discharge Until Flood Debris Elevation is Achieved

  7. Surveying Long Profile & Cross Sections • Run Tape Measure down the Thalweg • Establish Bench Mark Photo Credits: Gigi Richard

  8. Surveying Long Profile & Cross Sections Cont’d • Surveying the Thalweg • Slope = 0.0261 Photo Credit: Gigi Richard

  9. Surveying Long Profile & Cross Sections Cont’d • Surveying Cross Section 1 • Surveying Cross Section 3 Photo Credits: Gigi Richard

  10. Cross Sections 1 & 3 124 Feet Apart

  11. Pebble Count & Grain Size Distribution • 100 Grains Counted At Each Cross Section • Average D84 = 24 mm

  12. Critical Shear Stress, τc • Shields Equation • τc= τ*c(ρs – ρw)gD84 Where: • τ*c = Dimensionless Shear Stress • ρs, ρw = Density of Sediment (Quartz) & Water Respectively • g = Gravitational Constant • D84 = 84th Percentile of Grain Size Distribution • τc= 0.045(9.81 m/s2)(2650-1000 kg/m3)(0.024 m) • τc= 17.48 N/m2

  13. HEC-RAS Results • Channel Forming Discharge = 4 cubic Feet per Second • Frequency = ?? HEC-RAS Model At Cross Section 1 Q = 4 ft3/s Distance From Left Bank (ft)

  14. What about this August 16, 2010 Flood? • What was the discharge of this flow? Photo Credits: Teri Lindaur

  15. What about the flood? • Surveyed High Water Mark Using Flood Debris Indicators Photo Credits: Gigi Richard

  16. HEC-RAS Results for High Water Mark Estimate • Discharge of Flood on August 16, 2010 ≈ 200 cubic feet per second HEC-RAS Model At Cross Section 1 Flood Debris Q = 200 ft3/s Distance From Left Bank (ft)

  17. Red Canyon Wash’s Dry Channel Photo Credits: Greg Indivero

  18. August 16, 2010 Videos Video Credits: Teri Lindaur

  19. Conclusions • How often do these types of flows occur? • Speculation • Historical Events (September 7, 1978 ≈ 2,890 cfs) Photo Credits: Jim Johnson

  20. Acknowledgements • A Big Thank You Goes Out to the following: • Dr. Gigi Richard • Mrs. Teri Lindaur • Mr. Con Trumbull • Ms. HeidlHausner • Mr. Frank Jacobs

  21. References • Arcement, G. J., 1989, Guide for selecting Manning's roughness co-efficients for natural channels and flood plain, USGS water-supply paper: 2339, v. 38. • Cooke, R., Warren, A., Goudie, A., 1993, Desert Geomorphology: University College London, UCL Press Limited, p. 143-167. • Becker, A., DiPema, L, Ladig, K, Wellik, J, and Richard, G., 2007, Channel morphology and channel- forming discharge of No Thoroughfare Canyon, Colorado, Geological Society of America, Abstracts with Programs, Vol. 39, No. 6, p. 306 • Elliott, J.G. and Hammack, L.A., 2000, Entrainment of Riparian Gravel and Cobbles in an Alluvial Reach of a Regulated Canyon River: Regulated Rivers: Research and Management, v. 16, p. 37-50. • Knighton, D., 1998, Fluvial Forms and Processes: A New Perspective. London: Arnold, p. 383 • Richard, G.A., 2004, Flash Flooding at the Colorado National Monument 1921-2003: Colorado National Monument, National Park Service, p. 21 • U.S. Army Corps of Engineers (USACOE), Hydrologic Engineering Center, 2010, HEC-RAS River Analysis System Hydraulic Reference Manual, Version 4.1, U.S. Army Corps of Engineers, Davis, CA, 417 pp. • Van Steeter, M. M., and J. Pitlick. 1998, Geomorphology and endangered fish habitats of the upper Colorado River: historic changes in streamflow, sediment load, and channel morphology. Water Resources Research 34:303-316. • Wilcock, P. R., 2001, Toward a practical method for estimating sediment transport rates in gravel-bed rivers, Earth Surf. Processes Landforms 26, 1395 –1408. • Wilcock, P. R., Pitlick, J., Cui, Y., 2009, Sediment Transport Primer: Estimating Bed-Material Transport in Gravel-bed Rivers, U.S. Dept. of Agriculture, Forest Service, Rocky Mountain Research Station, 78 pp.

More Related