State of the River: Geomorphic Structure. Josh Wyrick, Ph.D. UC Davis

Transcription

1 State of the River: Geomorphic Structure Josh Wyrick, Ph.D. UC Davis 1

2 Geomorphic Structure Methodology Data Collection (topography, rating curve, hydraulics, substrate, vegetation & cover) GIS-Based Analyses DEM Map Production 2D Hydrodynamic Modeling Valley Characteristics Topographic Change Analysis Sediment Budget Change Processes Hydraulics Depth & Velocity Wetted Areas Morphological Units Integration with Biological Datasets 2

3 DEM Map Production Dry Creek Hammon Backwater 3

4 DEM Differences Map flow 4

5 Sediment Budget 26-ft DPD years since Englebright Net Fill Net Scour Max erosion ~19 mi from mouth (~4 mi d/s from Englebright) 45% of current export from Timbuctoo Bend Flow Segment Net Scour = 0.6 million ft 3 /y 5

6 Long-Term Thalweg Adjustment Allan James, 2012 Profiles extracted from 3-m DEM interpolated from contour maps Thalweg upstream of DPD has adjusted. ~85% of scour volume occurred out of channel 6

7 Topographic Change Processes Map Spatial patterns of scour/fill & 1999/2008 channels 9 Scour processes; 9 Fill processes; No Change areas 9 Lateral processes; 9 Vertical processes 7

8 Topographic Change Processes Tailings berm Vertical Annual Volume (%) Area of Change (%) Lateral Vertical Fill Lateral Lateral Vertical Vertical processes dominate overall. Vertical processes are net fill. Lateral processes are net scour. Both fill and scour processes are net vertical. Scour Lateral Vertical

9 Topographic Change Processes In Channel Changes in Depth Process Annual Volume % Process Average (in/year) Downcutting 10.4 Bar Emergence 6.4 In-Channel Fill 2.8 VS LF VF Cohesive Bank Retreat Berm Scour & Mass Failure LS LS Out of Channel Avulsion VS Process Annual Volume % Overbank Scour 19.2 VS Overbank Storage 18.0 VF Vegetated Overbank Storage 15.7 VF 9

10 Vegetation & Roughness Map 10

11 Substrate Map DPD 11

12 Substrate Characteristics Mean Diameter = 97.4 mm Typical range of Chinook spawning gravels 12

13 Post-New Bullards Bar Hydrology Baseflow: 880 cfs (Smartsville) 530 cfs (Marysville) Timbuctoo Bend at 5,000 cfs (Feb, 2004) 13

14 2D Hydrodynamic Model Inputs Validation 14

15 Hydraulics Maps 15

16 Inundation Maps 16

17 Transience of High Velocity Zones flow flow 17

18 Channel Characteristics Alluvial Valley Mean Slope = 0.16% 0.31% 0.20% 0.19% 0.14% 0.052% 0.13% 0.18% 18

19 Channel Characteristics Mean Sinuosity = 1.1 Value Sinuosity < 1.2 Low 1.2 < S < 1.5 Moderate > 1.5 High Sinuosity = Stream Length Centerline Length 19

20 Valley Characteristics Mean Entrenchment Ratio = 2.7 Dam Goldfields Ratio Entrenchment < 1.4 High 1.4 < ER < 2.2 Moderate > 2.2 Slight 20

21 Valley Characteristics Reach Englebright Dam Timbuctoo Bend Baseflow Width (ft) Bankfull Width (ft) Valley Width (ft) Parks Bar Dry Creek ,009 Daguerre Point Dam ,472 Hallwood Marysville The available river meander valley may be narrower in the region of the Goldfields as compared to historic extents; however, currently the Dry Creek and DPD reaches are the widest of all the reaches at all discharges. LYR MEAN

22 Morphological Unit Map 22

23 Morphological Unit Map 23

24 Morphological Unit Organization Abundance within Baseflow Non-random Organization Reach Abundant MU MU Area % Englebright Pool 41 Timbuctoo Pool 20 Parks Bar Riffle 19 Dry Creek DPD Fast glide & Slackwater Riffle transition Hallwood Fast glide 20 Marysville Pool 52 Lateral Variability Adjacency Collocation Longitudinal Distribution Longitudinal Spacing 24

25 MUs and Valley Characteristics Morphological unit Water surface slope (%) Ratio of baseflow wetted width to mean width Entrenchment ratio Mean % < 1.4 % > 2.2 chute fast glide pool riffle riffle transition run slackwater slow glide HIGHEST LOWEST 25

26 MUs and Habitat Availability Life Stage: Holding Spawning Rearing MU: Pool Riffle; Run; Slow Glide; Riffle Transition Slackwater Reach Percent Areas of Baseflow Channel Englebright Timbuctoo Parks Bar Dry Creek DPD Hallwood Marysville Total LYR

27 MUs and Chinook Spawning ~76% of Chinook redds occur in these 3 MUs 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*

28 MUs and Juvenile Rearing Habitat 400-ft sections (~2W) were randomly chosen for juvenile snorkel surveys. Snorkel survey area The percent MU abundance in each section equaled the reach-scale percentage. 28

29 MUs and Cover Elements Wood Pieces Wood Jams Human-Built Detritus 29

30 Publicly Available Maps from RMT Vetted & Available Now Topography Inundation zones Geomorphic reaches Vegetation LiDAR Vegetation presence/absence 2D model-predicted hydraulics for flows between ,400 cfs Morphological units Available Soon Substrate DEM difference Topographic change process Chinook spawning HSI for discharges 300-5,000 cfs O Mykiss spawning HSI for discharges 300-5,000 cfs Cover 30

31 Acknowledgements RMT Members UC Davis Lab Greg Pasternack Tarick Abu-Aly Rusty Barker Jen Carley Nick Depsky Dylan Garner Bobby Gonzalez Mathew Jian Leah Kammel Rafael Rodriguez Anne Senter Michael Strom Matt Vaughan Sooyeon Yi 31