Channel Morphology ofRed Canyon Wash

Gregory Indivero31 October 2011

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?

Research Questions

Location of Red CanyonRed & Columbus Canyons

Un-gauged,

Ephemeral Wash

5th Largest

Drainage of CNM

Satellite Photograph

Red

Canyon

Col

umbu

s Can

yon

Red Canyon Wash Study Reach

No

Thoroughfare

Canyon

Specific Study Reach Site

Fairly Straight Alluvial Channel

300 Feet Long≅ 20 Feet Wide

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

Methods

Surveying Long Profile & Cross Sections

Run Tape Measure down the ThalwegEstablish Bench Mark

Photo Credits: Gigi Richard

0 50 100 150 200 250 300 3504922

4924

4926

4928

4930

4932

4934

4936

4938

f(x) = − 0.0261428145273286 x + 4935.33757365684R² = 0.98459205971073

Red Canyon Wash Long Profile

Red Canyon Wash Thalweg

Energy Gradient (Slope)

Distance Downstream in Feet

Ele

vati

on in F

eet

Surveying Long Profile & Cross Sections Cont’d

Surveying the Thalweg

o Slope = 0.0261

Photo Credit: Gigi Richard

Surveying Long Profile & Cross Sections Cont’d

Surveying Cross Section 1

Surveying Cross Section 3

Photo Credits: Gigi Richard

0 10 20 30 40 50 604929

4930

4931

4932

4933

4934

4935

4936

4937

4938

4939

Cross Section 1

Distance From Left Bank in Feet

Ele

vati

on in F

eet

0 5 10 15 20 25 30 35 40 45 504928

4929

4930

4931

4932

4933

4934

Cross Section 3

Distance From Left Bank in Feet

Ele

vati

on in F

eet

o Cross Sections 1 & 3 124 Feet Apart

100 Grains Counted At Each Cross Section Average D84 = 24 mm

Pebble Count & Grain Size Distribution

1 10 100 10000

10

20

30

40

50

60

70

80

90

100

Red Canyon Wash

Cross Section 1Cross Section 2Cross Section 3

Particle Diameter (mm)

Perc

ent

Fin

er

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

Critical Shear Stress, τc

τc= 0.045(9.81 m/s2)(2650-1000 kg/m3)(0.024 m)

τc= 17.48 N/m2

Channel Forming Discharge = 4 cubic Feet per Second

Frequency = ??

HEC-RAS Results

Distance From Left Bank (ft)

HEC-RAS Model At Cross Section 1

Q = 4 ft3/s

What was the discharge of this flow?

What about this August 16, 2010 Flood?

Photo Credits: Teri Lindaur

Surveyed High Water Mark Using Flood Debris Indicators

What about the flood?

0 50 100 150 200 250 300 3504922

4924

4926

4928

4930

4932

4934

4936

4938

f(x) = − 0.0261428145273286 x + 4935.33757365684R² = 0.98459205971073

Red Canyon Wash Long Profile With High Water Mark

Red Canyon Wash Thalweg

Energy Gradient (Slope)

REW

LEW

Distance Downstream in Feet

Ele

vati

on in F

eet

Photo Credits: Gigi Richard

Discharge of Flood on August 16, 2010 ≈ 200 cubic feet per second

HEC-RAS Results for High Water Mark Estimate

Distance From Left Bank (ft)

HEC-RAS Model At Cross Section 1

Q = 200 ft3/s

Flood Debris

Red Canyon Wash’s Dry Channel

Photo Credits: Greg Indivero

August 16, 2010 Videos

Video Credits: Teri Lindaur

How often do these types of flows occur?◦ Speculation◦ Historical Events (September 7, 1978 ≈ 2,890 cfs)

Conclusions

Photo Credits: Jim Johnson

A Big Thank You Goes Out to the following:

◦ Dr. Gigi Richard

◦ Mrs. Teri Lindaur

◦ Mr. Con Trumbull

◦ Ms. HeidlHausner

◦ Mr. Frank Jacobs

Acknowledgements

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.

References