sediment transport in stream assessment and design august 1 … · on exercises for estimating...

This course is intended for those who wish to understand and apply the principles of sediment transport to alluvial channel assessment and design. Principles of open channel flow and sediment transport are combined with watershed-scale, hydrologic and sediment source analysis to place channel assessment and design in the appropriate context. Threshold and alluvial channel design methods are presented along with guidelines for assessing and incorporating uncertainty. The course balances advance reading, lecture, field work, and hands-on exercises for estimating sediment supply, calculating sediment transport rates, and forecasting channel response to water and sediment supply. This course is intended for participants who are familiar with basic principles of river geomorphology.

Sediment Transport in Stream Assessment and DesignAugust 1-5, 2016 Logan, Utah

DEPARTMENT OF WATERSHED SCIENCES

Agency 11        Industry 7          Academic 14

Geo/Hydro 21      Eco 4    Civil Engineering 11 

Cache Valley

HeberValley

Summit Ck(Tuesday)

Cub R(Wednesday)

Little Bear R(Monday)

Merrill‐CazierLibrary 

(Thursday)

Cache Valley(Monday – Thursday)

Logan R(Wednesday)

G

G

Provo R(Friday)

Heber Valley(Friday)

Logan

SLC

Exit Strategy(Friday)

Given:Post‐dam flowsUpstream sediment supplyObjective of a dynamic channel supporting a trout population

With:Start    and finish    points & 

existing topography

Use:Spreadsheet toolsHEC‐RAS

To Develop:Channel layout and geometry totransport supplied sedimentwith available flow 

1‐d hydraulic model of designto contain design discharge

Sediment mass balance for channel dynamics

What is the supply of water and sediment to a stream & what do you want to do with it?

I. How often does sediment move?

II. What is the sediment balance?

Discharge QBed material DChannel Geometry

HydraulicsIncipient Motion

Discharge QSediment Supply Qs & DChannel Geometry

HydraulicsTransport Capacity Qs & D

Input  +  Storage =  Output

Surplus or Deficit?Stored sediment is the real geomorphic and restoration topic!

Wha

t is the

 supp

ly of w

ater and

 sedimen

t?What do you w

ant to do with it?

Flow COMpetence

Transport CAPacity vs Sediment Supply

Build 1d flow modelAssess critical discharge for incipient motion

Estimate sediment sources, sinks, flux

Estimate transport rates & evaluate channel change

Design channel to transport sediment supply & maintain dynamics

1. Develop flood series, specify flood frequency Design Q.

2. Estimate sediment supply: develop supply sediment rating curve [Monday, Wednesday]

3. Planning phase: What slope S will transportthe sediment supply with the available flow? Calculate (b, S) combination {S and valley slope determine sinuosity} [Thursday]

4. Develop flow duration curve

5. Design phase: Develop trial design, w/ desired channel geometry &composition.Use 1-d model to route sediment through the design reach over the flow duration curve.{Build 1-d hydraulic model for trial design. Calculate cumulative transport over flow duration curve at each section; evaluate sediment continuity.} [Tuesday, Thursday]

6. Bottlenecks or blowouts? Adjust for sediment continuity [Thursday]

0

0.002

0.004

0.006

0.008

0.01

0.012

0 5 10 15 200

0.5

1

1.5

2

2.5

3

3.5

Slope Case 1 Slope Case 2Depth Case 1 Depth Case 2

Channel Width (m)

Slop

e Depth (m

)

Discharge 1 = 15.0

Discharge 2 = 25.0

Sed Supply 1 = 954 kg/hr

Sed Supply 2 = 2862 kg/hr

Design steps

1

10

100

1000

100 1000 10000

River RDMidwayCasperville

Discharge (cfs)

Tran

spor

t Rat

e (to

ns/d

ay)

Does not include transport samples <200g for the >16mm size classNo meaasured transport in this size range at White Bridge

> 16 mm

WirelessFind Bluezone – Sponsored Access

Sponsor Code: yihopubu(Group Name: Sediment Workshop)

Materials

pdf color slides of presentationsPaper print of some presentation slides

Paper copies of field assignmentsElectronic copies of assignments, spreadsheets, readings

https://qcnr.usu.edu/courses/sed_materials

Depart MTW: NR Parking LotDinner Mon 7p: 1624 Sunset Dr

Dinner Wed: NR Atrium Workshop 101 Merrill‐Cazier Library

Tyler Allred  801 358‐1868Peter Wilcock 443 564 6253

Dinner Mon 7p: 1624 Sunset Dr

20 min walk from campus443 564 6253

Golf Course

Golf C

ourse

Friday Morning

I‐80 Exit 146, US 40 toward Heber, Vernal, ProvoPass Jordanelle Reservoir on left, head down into Heber ValleyRight at first stop light, onto River RoadRight into Provo River Restoration Project Office

PRRP Office