U.S. Department of the Interior

U.S. Geological Survey

Goal 7 Modeling Rev

and Recommendati

Scott Wright, USGS California Water Sci

June 25-26, 2007 Technical Work Grou
Outline

 Why use models? What’s behind these models? Time and space scale issues Modeling approach for the Colorado River in  Integration of modeling and monitoring - his Recommendations from recent review Future directions/Proposed FY08 work
Why use models?

 To make predictions that allow for the evaluati

scenarios.

 Accurate predictions of system response lead 

resource management – i.e. there is less need 

Models Mo
Why use models in Grand Cany

Is there a ‘Flow-Only’ operation that will restore and sandbar habitats over decadal time scales? If yes, operation?

Model(s)

Tributary 

inputs

Dam 

operations

Basin 

hydrology

T

This should be the ultimate goal – but it is ambitious and mincrementally – may require a suite of models of various sc

Multi-year/decadal time scale
Why use models in Grand Cany

How do dam operations, hydrology, and meteorolodetermine mainstem and nearshore water temperathe CRE?

Model(s)

TCD

Dam 

operations

Basin 

hydrology

Meteorology/

climate
What’s in these models?

dt

ff

t

f tt 12 −

→

∂

∂

t

∂

∂η

Models attempt to reproduce known physica

Change in land surface elevation with time

Flow - momentum and mass conservation:

Sediment – mass conservation:

Temperature – heat balance:

Equations are linearized and solved numerically by “steppin

dx

f

x

f

→

−

x 

2

∂

∂
Scale is a major issue in mode

The type of model used is dependent on the sca

Spatial scale

Time scale

meter km 

hours months years

As physicallybased as possible

Decreasing spatial reso

Decreasing temporal resolut

Decreasing accuracy

Simplifying assumptions
Canyon geomorphology - range in 

Spatial scale

Time scale

meter km 

hours months years

Sandbars

BHBFs

Daily

fluctuations

Monthly

variations

Multi-year

hydrology

Pool-fan-eddy

complex
Modeling Approach for Grand Cany

Reach scale, days

Use data and 

models to determine 

required complexity

Use model and data to evaluate importance of various processes 

Potentially “nested”

Model(s) Inputs 
Canyon sediment modeling timeline

1960

1990

1970

1980GCD

Laursen – computed post-dam transport rates; not really a “model”

Randle and Pemberton – 1D, steady flow, no eddies, systemwide, month-to-year time scale

Wiele and others– 2D, steady flow, km-scale reaches with eddies, day-toweek time scale

Topping –Paria River model

Wiele and others unsteady flow, 100 scale with eddies, to-month time sca

Schmeeckle and otheunsteady flow, km scaeddies, hours-to-day t
Sediment Review Panel Recommen

 The modeling program needs better integration w

program – formulate an integrated research plan

 It is time to update the Wiele 2D model as major a

been made in multi-dimensional modeling over thlots of new data are available; evaluate readily avpackages (such as Delft3D) and available data

 Wiele 1D model is a step forward but more work 

evaluate its predictive capabilities – continue to immodel based on updated MD model

 Continue efforts by Arizona State University (Mar

group) to model sandbar stability (i.e. mass failurcollapse), including laboratory experiments
Linking modeling and monitori

Modeling should be conducted in parallel with monito

“Integrated approach to modeling and modeling”, fr
Have modeling and monitoring bee

Laursen Update conceptual 

model? No

Adjust monitoring network? No

No monitoring

EIS data

Randle and 

Pemberton

Adjust monitoring network? No

No monitoring

Update 

conceptual 

model? No

90-91 EXP

Update 

conceptual 

model? YES!

1996 BHBF, 2000 LSSF

Wiele 1D 

model

Adjust monitoring network? YES!

Mass balance and FIST

Update 

conceptual 

model? Yes

2004 BHBF

Updat

next s

Adjust monitonetworYes

time

time
Delft3D modeling package

 Off-the-shelf package lots to offe

 2D and 3D options for flow and transport Sediment transport with multiple grain-size

and bed layering history (i.e. stratigraphy)

 Water temperature in 3D with full surface h

balance (also many other WQ constituents)

 Current cooperative agreement with USGS, 

technical support

 Fully documented with many applications a
Delft3D initial evaluations

01-Aug-2007 08:30:00

x coordinate (m) 

→

y coordinate (m) →

2.19 2.191 2.192 2.193 2.1

5.971

5.9715

5.972

5.9725

5.973

5.9735

5.974

5.9745

5.975

5.9755

x 105

Eminence backwater temper

Example for illustrative purposes only
Delft3D initial evaluations

30-mile eddy deposition during h

x coordinate (m) 

→

y coordinate (m) →

2.195 2.196 2.197

x 105

6.116

6.1165

6.117

6.1175

6.118

6.1185

6.119

6.1195

6.12

6.1205

x 10

Example for illustrative purposes only
Proposed FY08 activities

 Develop multi-dimensional models (Delft3D) of flow, 

sediment transport for reaches with available topograreaches). Principal Investigators – Scott Wright and Drequested budget: $135,000 (additional funds being for support of Craig Anderson of GCMRC)

 Continue efforts to model sandbar mass failure/stabi

laboratory experiments at ASU. Principal Investigatorequested budget: $55,000.

 Continue efforts to understand the relationships betw

sediment grain-size, and suspended-sediment grain-pursue the potential for a model that relies on “shiftinPrincipal Investigator – David Rubin; requested budg

Total budget request: $220,000Currently in FY08 budget: $117,00Additional funding needed: $103,0
Questions?