Single and Multidimensional Sediment Yield and Transport Tools · Urban development issues – 2-d...

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Advanced Tools

Single and Multidimensional Sediment Yield and Transport Tools

US Army Corpsof EngineersDetroit District

Great Lakes Hydraulics and Hydrology Office

Sediment Yield

Definition: The total sediment outflow from a drainage basin during a specific time (tons/year)

Precipitation

Sediment Out

Sediment Transport

Definition: Sediment moving downsteam by the action of flowing water, including the quantification of scour and deposition.

Advantages

• High spatial resolution • Ability to model individual processes• Increased confidence

Disadvantages

• High level of modeling expertise required • Extensive calibration/validation data required • Time intensive • Expensive

When do we need a more sophisticated tool?

• When the processes are very complicated

• When a simple tool doesn’t give the correct answer

What makes a tool more complex?

• Adding Dimensions1-d model2-d model3-d model

• Adding more physics-based processes

• Increasing spatial and temporal resolution

What does a 1-d model mean?

Model Input: Q=100 ft3/s

Model Determines: Area = 25 ft3

Velocity = Q/A = 100/25= 4 ft/s

Velocity is the same everywhere in the x-section (HEC-RAS is 1-d)

Another way to look at 1-d limitations

Ave (1-d) velocity

Velocity ProfileNo Friction With Friction

Under-estimating velocity

Over-estimating velocity

From Rosgen 1996

Measured VelocitiesNote Multi-dimensional Nature

Flow with strong 3-dimensional nature

Shiono and Knight, 1991

Hydrology/Sediment Yield Model LimitationsLumped vs. Distributed Models

Lumped Models Distributed Models

Hydrology/Sediment Yield Model LimitationsLumped vs. Distributed Models

Lumped Models Distributed Models

• Time consuming to set up• Models are sometimes unstable and require considerable messaging• Slow running models• Can provide high-resolution answers• Typically used on smaller catchments

SWATGSSHACASC2D

• Simple to set up and run• Can be used by non-modelers• Used on large watersheds

SCS MethodRUSLERational MethodWCS

Creating the lumps in a lumped model

Lumped vs Distributed Model

DistributedLumped

Examples of model applications

• Clinton River

Urban development issues – 2-d sediment yield model

Shoaling problem – 3-d sediment transport model

• Sheboygan River

Contaminated sediment capped by clean sand – 3-d sediment transport model

• Saginaw RiverFeasibility of sediment trap – 1-d sediment transport model

Erosion of agricultural field – 2-d sediment yield model

Distributed Parameter ModelClinton River

• Urbanization- Landuse change- Effect of buffer strips- Effect of lot size- Effect of retention basins- Wetland loss- Distance from river- Controlling Rooftop Runoff- Controlling Construction Runoff

• Contribution from bank erosion• Effect of spillway and inflatable weir

Clinton River SubwatershedsUS Army Corpsof EngineersDetroit District

Detailed Model Area

Development of GSSHA GridUS Army Corpsof EngineersDetroit District

Integration of Aerial Photography,DEM and Parcel Data

Orion Rd.Adam

Integration of Land Uses and Buffer Strips

Buffer strip

Apply Precipitation

Sediment Flux Gage Locations

0 100 200 300 400 500

time (min)

Short GrassLong Grass

ForestBermuda grass

Bare FieldRange

0 100 200 300 400 500

time (min)

Short Grass

Long GrassForest

Bermuda grassBare FieldRange

0 100 200 300 400 500

time (min)

Short GrassLong Grass

ForestBermuda grass

Bare FieldRange

10m buffer. 20m buffer. 30m buffer.

Sediment Flux at Buffer Strips of Varying Width

Clinton River

Small Scale Application

Effect of Lot Sizes

1 acre

1/2 acre

1/3 acre

1/4 acre

1/5 acre

1/8 acre

1/10 acre

1/10 acre lots

1/3 acre lots

Effect of Lot Size

0 200 400 600 800 1000

Time (min)

00.050.10.150.20.250.30.350.40.450.50.550.6

1 AcreSediment LoadDischarge

0 200 400 600 800 1000

Time (min)

00.050.10.150.20.250.30.350.40.450.50.550.6

1/2 AcreSediment LoadDischarge

0 200 400 600 800 1000

Time (min)

00.050.10.150.20.250.30.350.40.450.50.550.6

0 200 400 600 800 1000

Time (min)

00.050.10.150.20.250.30.350.40.450.50.550.6

0 200 400 600 800 1000

Time (min)

00.050.10.150.20.250.30.350.40.450.50.550.6

0 200 400 600 800 1000

Time (min)

00.050.10.150.20.250.30.350.40.450.50.550.6

0 200 400 600 800 1000

Time (min)

00.050.10.150.20.250.30.350.40.450.50.550.6

Clinton River

Small Scale Application

Small Scale Contributions

Rooftop runoff

Rooftop infiltration Tanks

Clinton River

Controlled Runoff from Construction Sites

Scenarios

No control

Sand bags

Silt fences

Furrowed

Terracing

Controlled Runoff from Construction Sites

P (conservation practice factor) Values Obtained from the Alberta Transportation Department (Alberta Transportation, 2003).

Model scenario Variable No

control Sand Bags

Rock Silt fences Furrowed Terracing

P value 1.0 0.9 0.8 0.6 0.5 0.1 Volume of infiltrated water (m3) 17100 17100 17100 17100 17100 17100 Volume of discharge (m3) 7000 7000 7000 7000 7000 7000 Net sand eroded from surface (m3) 980 890 810 640 560 220 Net silt eroded from surface (m3) 180 170 150 120 100 40 Net clay eroded from surface (m3) 61 56 51 40 35 14 Total sand into channels (m3) 5 5 5 5 5 5 Total silt into channels (m3) 5 16 16 16 16 16 Total clay into channels (m3) 5 5 5 5 5 5

SummaryClinton River Sediment Yield

• The resolution needed to model issues such as lot size, roof-top runoff, construction practices, etc. is only possible using a distributed (2-d) model

Clinton River

• Urbanization- Landuse change- Effect of buffer strips- Effect of lot size- Effect of retention basins- Wetland loss- Distance from river

River BathymetryUS Army Corpsof EngineersDetroit District

Inflatable Weir

FlowFl

Inflatable Weir and Shoal

Inflatable WeirUS Army Corpsof EngineersDetroit District

Curvilinear Model GridUS Army Corpsof EngineersDetroit District

Modeling Flows with EFDC

Storm Event Bed Change

Modeling Sediments with EFDC

• Clinton River

• Sheboygan River

Lake Michigan

Native Material

Sheboygan River

Sheboygan River Bathymetry

CH3D-SED Modeling Grid

Bed Characterization

Bed Change

A 1-d model would not be able to represent this complex flow structure

• Clinton River

• Sheboygan River

Sub-basin Map

Model Domain, Hydrodynamics and Hydrology Links

Sediment Transport Model HEC-6

+AGNPS

Hydrodynamics

Feasibility of Sediment Traps

0 5000 10000 15000 20000 25000 30000 35000

Q (cfs)

Feasibility of Sediment Traps

Percent exiting sediment trap

Summary

• Simple models can be very useful, but the user must understand their limitation

• More-complex models allow insight into processes unresolvable with simple models, but are often very time consuming, data intensive and expensive

• By clearly identifying the problem to be solved, an appropriate model can be selected

Questions?

Contact:Dr. Jim Selegean, P.E., P.H.

U.S. Army Corps of Engineers, Detroit DistrictGreat Lakes Hydraulics and Hydrology Office

477 Michigan AveDetroit, MI 48226

313.226.6791

james.p.selegean@usace.army.mil

Single and Multidimensional Sediment Yield and Transport Tools · Urban development issues – 2-d...

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