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New Features for HEC-RAS 5.0
Martin Teal, P.E., P.H., D.WRE
August 22, 2017
New Sediment Features in HEC-RAS 5.0
(and 5.0.1/2/3/x)
Thanks to Stanford Gibson, HEC
Topics
1. Unsteady Sediment Transport
2. USDA-ARS Bank Stability and ToeErosion Model (BSTEM)
3. Other New Sediment Features
Develop and Calibrate a Good Hydraulic Model First
-Variable n-values-Ineffective Flow Areas
HEC-RAS Sediment Data InputStarts here:
New Sediment Features in HEC-RAS 5.0.3
1. Unsteady Sediment Transport
2. USDA-ARS Bank Stability and ToeErosion Model (BSTEM)
3. Other New Sediment Features
Quasi- vs Unsteady Sediment Files
Q
t
Quasi-Unsteady Flow
tt
Quasi-Unsteady Flow Unsteady Flow
tt
Quasi-Unsteady Flow Unsteady Flow
tt
Quasi-Unsteady Flow Unsteady Flow
Case Study:Spencer Dam
Spencer Dam Flush
Gibson, S. and Boyd, P. (2016) “Monitoring, Measuring, and Modeling a Reservoir Flush on the Niobrara River in the Sandhills of Nebraska,” Proceedings, River Flow 2016, ed Constantinescu et al., 1448-1455.
Gibson, S. and Boyd, P. (2016) “Designing Reservoir Sediment Management Alternatives with Automated Concentration Constraints in a 1D Sediment Model,” Proceedings International Symposium on River Sedimentation.
.
Spencer HEC-RAS Model
400 600 800 1000 1200 1400 1600
1485
1490
1495
1500
1505
1510
Station (ft)
Elev
atio
n (ft
)
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D/S Concentration Threshold
HEC-RAS Model Concentration
Mississippi River Unsteady HEC-RAS Sediment Model (HEC)
Conowingo Dam Studies
Lower Susquehanna River Reservoirs Dynamic equilibrium Potential impacts on
Chesapeake Bay water quality
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Figure 1-2 from Lower Susquehanna River Watershed Assessment (2015)
Introduction and Background• Safe Harbor Dam Constructed 1931 75 feet tall, impounds Lake Clarke (7,360 acres)
• Holtwood Dam Constructed 1910 55 feet tall, impounds Lake Aldred (2,400 acres)
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Safe Harbor Dam, October 24, 2010 (U.S.C.G.Aux5DNR on Flickr) Holtwood Dam, December 2015 (http://suereno.blogspot.com)
Study Goals• Develop unsteady, 1D sediment transport model Marietta, PA to Holtwood Dam (20.4 miles)
• Aid in parameterization of Chesapeake Bay Watershed Model
• Input for HDR model of Conowingo Pond
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Study Goals – Model Improvements• Improve upon past studies using HEC-RAS 5.0 Model (unsteady) Solves the unsteady flow equation, routing flow and
explicitly accounting for storage and travel time Conserves volume, important in reservoir systems Cohesive and non-cohesive sediments
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Model Boundary Conditions and SetupGeometric DataFlow &
Temperature DataSediment Data
Bed sediment (12 size classes)
Inflow loads
Transport FunctionSediment
ParametersDam Operations
Rating curves
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Safe Harbor Dam
Holtwood Dam
• Sediment Volume Change 2008-2013
(calibration) 2013-2015
(verification)
Model Calibration and VerificationHydraulic Calibration at Marietta, PA
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20 31 10 20 28 10 20 31Jan2010 Feb2010 Mar2010
230
235
240
245
250
0
100000
200000
300000
400000
500000
Plan: Gate2-T River: SUSQ Reach: LSUS RS: 187225.3
Time
Stag
e (ft
)
Flow
(cfs)
Legend
Stage
Obs Stage
Flow
Missing Data
28 10 20 31 10 20 30 10 20Mar2011 Apr2011 May2011
230
235
240
245
250
0
100000
200000
300000
400000
500000
Plan: Gate2-T River: SUSQ Reach: LSUS RS: 187225.3
Time
Stag
e (ft
)
Flow
(cfs)
Legend
Stage
Obs Stage
Flow
Missing Data
Model Calibration and Verification (2)Sediment
Transport Calibration January 2008 –
August 2013 Several large
events, including Tropical Storm Lee
Sediment Transport Verification August 2013 -
October 2015 Unusually low flows
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Observed vs. Modeled Cumulative Volume Change: Lake Clarke Sub-Areas 1-5, January 2008 – October 2015
Observed vs. Modeled Cumulative Volume Change: Lake Aldred Sub-Areas 3-6, January 2008 – October 2015
Summary of Results
Additional Runs Historical flow events applied to end of simulation
Results
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Increased transport on rising limb
Decreased transport on falling limb
Lateral Structures and Diversions
Sedi
men
t Dive
rted
(tons
)
Sedi
men
t Dive
rted
(tons
)
Lateral Structures and Diversions
Mixed Flow Regime Sediment Model
New Sediment Features in HEC-RAS 5.0.3
1. Unsteady Sediment Transport
2. USDA-ARS Bank Stability and ToeErosion Model (BSTEM)
3. Other New Sediment Features
Collaborators: Eddy Langendoen, PHD – USDA-ARSAndrew Simon, PhD – Cardno-Entrix
USDA-ARS Bank Stability and Toe Erosion ModelHEC-RAS/BSTEM
Three Interacting Processes
1. Vertical Bed Adjustment
2. Geotechnical Bank Failure
3. Toe Scour
∆z ~ Qs - Gs
∆x ~ M(τ-τC)
FS ~ FD - FR
-1.00
0.00
1.00
2.00
3.00
4.00
5.00
6.00
-1.00 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00STATION (M)
ELEV
ATIO
N (M
)
Base of layer 1
Base of layer 2
Base of layer 3
Base of layer 4
Base of layer 5
Eroded Profile
Initial Profile
Water Surface
Toe Erosion Model
Bank StabilityModel
-1.00
0.00
1.00
2.00
3.00
4.00
5.00
6.00
-10.00 -5.00 0.00 5.00 10.00 15.00
STATION (M)
ELEV
ATIO
N (M
)
bank profile
base of layer 1
base of layer 2
base of layer 3
base of layer 4
base of layer 5
failure plane
water surface
water table
USDA-ARS Bank Stability and Toe Erosion Model (BSTEM)
USDA-ARS BSTEM Interface
Three Methods:1. Pre-Defined Default Parameters2 .Single Set of User Defined Material3. Layers of Unique Material at a Bank
Defining Bank Material
Clark and Wynn (2007)
Soil Properties
(a) Incision
(b) ToeScour
(c) BankFailure
Interaction of all three process
http://www.eng.buffalo.edu/glp/events/summer2008/week1/full/8-GoodwinCreekDesign.pdf
Images by Andrew Simon (CardnoEntrix)
1996 2006
GoodwinCreek
Goodwin Creek HEC-RAS/BSTEM Model
Goodwin Creek HEC-RAS/BSTEM Model
Gibson, S., Simon, A., Langendoen, E., Bankhead, N., and Shelley, J. (2015) “A Physically-Based Channel-Modeling Framework Integrating HEC-RAS Sediment Transport Capabilities and the USDA-ARS Bank-Stability and Toe-Erosion Model (BSTEM),” Federal Interagency Sediment Conference, SedHyd Proceedings.
Missouri River HEC-RAS BSTEM Model
Modeled and Target Longitudinal Cumulative Mass Change over 1960 to 2011 Calibration Period.
Calibration Reach
RM 773.76
Bank Protrusion
2007 2015
RM 773.76
RM 794.25
RM 766.13
New Sediment Features in HEC-RAS 5.0.3
1. Unsteady Sediment Transport
2. USDA-ARS Bank Stability and ToeErosion Model (BSTEM)
3. Other New Sediment Features
Reservoir Deposition Method
Initial Bed
Veneer Method
Initial Bed
ReservoirMethod
Reservoir Deposition Method
950 1000 1050 1100
1070
1080
1090
Station (ft)
Ele
vatio
n (ft
)
25000 30000 35000
1040
1050
1060
1070
1080
1090
Main Channel Distance (ft)
Ch
Inve
rt E
l (ft)
HEC-RAS Results (profile over time)
HEC-RAS XS Results (Reservoir Sediment Erosion)
Springville Dam Removal ModelBy Waleska Echevarria(ERDC-CHL)
Simplified Channel
Evolution Model
Multiple Movable Bank Limits
Another Veneer Method Departure:Floodplain Deposition
Floodplain Deposits on the Missouri River from the
2011 Flood
T. Branß, A. Dittrich, and F. Núñez-González(Technische Universität Braunschweig)
Reproducing natural levee formation in an experimental flume River Flow 2016
0.7 m0.6 m0 m 2 m
z
y0.0 cm
10.4 cm
1:1D
hm
ydymax
Floodplain Deposition Options in 5.1
Limerinos Brownlie
Bed Roughness Predictors
Bed Roughness Predictors
Bed Roughness Predictors:Reach Average
Computing an n-value at each XS based on gradational and hydraulic parameters can be noisy and prone to negative feedbacks. Therefore, cross sections can be grouped together into reaches to compute a single n-value from reach weighted parameters.
Navigation Dredging
Substrate Mining
Substrate Mining
Copeland Mixing Method (Exner 7)
Major differences between Exner 5 and Exner 7
Thomas (Exner 5) Copeland (Exner 7)Active Layer (La) computation based on Equilibrium Depth (Deq).
Active Layer (La) computation based on 15% of Water Depth or 3d90.
Linear Armor Ratio. Polynomial Armor Ratio.
Armors more rapidly, ↓ erosion. Armors more gradually, ↑ erosion.
“The arbitrary maximum cover layer thickness of 2 ft may hinder deposition during low energy conditions. Mixing of fine material will probably result in underestimation of scour during high flows. Erosion of fine material may be too severely constrained by (cover formation assumptions). “ (HEC 1996 HEC 6 Manual, p 28)
Questions?
Holtwood Dam, September 10, 2011 (TheGates1210 on YouTube)