State of the River: Geomorphic Structure Josh Wyrick, Ph.D. UC - - PowerPoint PPT Presentation
State of the River: Geomorphic Structure Josh Wyrick, Ph.D. UC Davis 1 Geomorphic Structure Methodology Data Collection (topography, rating curve, hydraulics, GIS-Based Analyses substrate, vegetation & cover) 2D DEM Map Hydrodynamic
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Data Collection (topography, rating curve, hydraulics, substrate, vegetation & cover) DEM Map Production GIS-Based Analyses 2D Hydrodynamic Modeling Morphological Units Integration with Biological Datasets Topographic Change Analysis Hydraulics Valley Characteristics
Sediment Budget Change Processes Depth & Velocity Wetted Areas
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Dry Creek
Hammon Backwater
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flow
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Flow 26-ft DPD 58-67 years since Englebright Max erosion ~19 mi from mouth (~4 mi d/s from Englebright) 45% of current export from Timbuctoo Bend Net Scour Net Fill Segment Net Scour = 0.6 million ft3/y
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Allan James, 2012
Profiles extracted from 3-m DEM interpolated from contour maps
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Annual Volume (%) Area of Change (%)
Lateral 30 18 Vertical 70 82 Fill 49 58 Lateral 18 13 Vertical 82 87 Scour 51 42 Lateral 42 25 Vertical 58 75
processes are net scour.
vertical. Lateral Vertical
Tailings berm
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Process Annual Volume % Downcutting 10.4 Bar Emergence 6.4 In-Channel Fill 2.8 Process Annual Volume % Overbank Scour 19.2 Overbank Storage 18.0 Vegetated Overbank Storage 15.7 Process Average (in/year) Cohesive Bank Retreat
Berm Scour & Mass Failure
Avulsion
In Channel Out of Channel Changes in Depth
VS LF VF VS VF VF LS LS VS
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DPD
Typical range of Chinook spawning gravels
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Timbuctoo Bend at 5,000 cfs (Feb, 2004)
13 Baseflow: 880 cfs (Smartsville) – 530 cfs (Marysville)
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flow flow
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0.052% 0.13% 0.18% 0.14% 0.19% 0.20% 0.31%
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Value Sinuosity < 1.2 Low 1.2 < S < 1.5 Moderate > 1.5 High
Sinuosity = Stream Length Centerline Length
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Ratio Entrenchment < 1.4 High 1.4 < ER < 2.2 Moderate > 2.2 Slight
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Goldfields
Dam
The available river meander valley may be narrower in the region
compared to historic extents; however, currently the Dry Creek and DPD reaches are the widest of all the reaches at all discharges.
Reach Baseflow Width (ft) Bankfull Width (ft) Valley Width (ft) Englebright Dam
120 169 415
Timbuctoo Bend
205 273 544
Parks Bar
199 307 976
Dry Creek
248 419 1,009
Daguerre Point Dam
197 379 1,472
Hallwood
183 330 889
Marysville
174 231 562
LYR MEAN
195 319 968
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Reach Abundant MU MU Area % Englebright Pool 41 Timbuctoo Pool 20 Parks Bar Riffle 19 Dry Creek Fast glide & Slackwater 18 DPD Riffle transition 28 Hallwood Fast glide 20 Marysville Pool 52 Abundance within Baseflow Non-random Organization Lateral Variability Longitudinal Distribution Adjacency Collocation Longitudinal Spacing
Morphological unit Water surface slope (%) Ratio of baseflow wetted width to mean width Entrenchment ratio Mean % < 1.4 % > 2.2 chute 0.416 0.47 2.6 14.8 66.7 fast glide 0.038 0.96 3.1 4.7 72.3 pool 0.013 0.93 2.4 20.9 37.5 riffle 0.765 0.94 2.6 10.3 65.3 riffle transition 0.124 1.14 3.3 4.1 84.3 run 0.118 0.78 3.2 2.4 89.2 slackwater 0.027 1.58 1.8 slow glide 0.030 1.00 2.6 14.3 42.9
25 HIGHEST LOWEST
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MU % Redds
Riffle 39.5 Riffle Transition 18.5 Run 18.4 Fast Glide 9.3 Chute 4.0 Slow Glide 3.4 Slackwater 1.9 Lateral Bar 1.6 Point Bar 0.6 Pool 0.5 Medial Bar 0.2 Unknown* 2.0
~76% of Chinook redds
these 3 MUs
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400-ft sections (~2W) were randomly chosen for juvenile snorkel surveys. The percent MU abundance in each section equaled the reach-scale percentage.
Snorkel survey area
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Wood Pieces Wood Jams Human-Built Detritus
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