THE FUTURE OF COMPUTER

MODELING OF COASTAL WETLAND,

ESTUARINE, AND RIVERINE SYSTEMS

Freek Scheel & Ehab Meselhe

November 2015

TEAM EFFORT

• The Water Institute of the Gulf – Natural Systems Modeling and Monitoring

• Ehab Meselhe

• Hoon Jung

• Ashok Khadka

• Kazi Sadid

• Katelyn Costanza

• Fei Xing

– Physical Processes and Sediment Systems • Mead Allison

• Cyndhia Ramatchandirane

• Dallon Weathers

• Brendan Yuill

– Coastal Ecology • Tim Carruthers

• Melissa Baustian

• Ann Hijuelos

• Leland Moss

• Kelly Darnell

• Caitlin Pinsonat, Blake Thompson, Dominque Henson, Kinsey Vernon, Shannon Matzke

TEAM EFFORT

• Deltares – Johannes Smits

– Bas van Maren

– Valesca Harezlak

– Michel Jeuken

– Freek Scheel

• University of Louisiana-Lafayette – Scott M. Duke-Sylvester

– Jenneke M. Visser

– Mark Hester

• Louisiana State University – Sibel Bargu and Jamal Mathurin

– Dubrakvo Justic

– John White

– Sam Bentley

– Tommy Blanchard

PROJECT GOALS

Produce a validated model capable of simulating:

Morphological processes during the creation of a

new delta and wetland areas

Nutrient effects to wetland vegetation, soil, and

estuarine primary producers of Breton Sound and

Barataria Basins.

MODELING APPROACH

Hydrodynamics

Morphodynamics Nutrient Dynamics

Integration of Nutrient and Morphodynamic Modules to

assess performance of restoration strategies

Vegetation

MODEL OVERVIEW

6

D-FLOW with SED-

ONLINE MORFAC 40 – approx. 2 yrs. – 1 day

Initialization phase

Iteration phase

* This runs outside the 1-month aim of the iteration phase (can be run long in advance, irrelevant any for scenarios)

* Aim: 1 wall-clock-month to run 50 yrs. of combined D-FLOW, SED-ONLINE, D-WAQ & LAVegMod.DM modules

Field input

Equilibrium bathymetry

Equilibrium stratigraphy

D-FLOW 1 yr. – 4 days

LAVegMod.DM Few hours

Annual hydro conditions

Trachytopes through scripting

Updated initial conditions for each iteration, includes:

- Stratigraphy (& bathy)

- Trachytopes

T = 50 yrs. = N * Δt Assumed N = 5 & Δt = 10 yrs.

D-FLOW with SED-

ONLINE MORFAC 40 – Δt yrs. – approx. Δt/2 in days

D-FLOW 1 yr. – 4 days

Updated bathymetry & stratigraphy

Annual hydro conditions

LAVegMod.DM Few hours

Trachytopes through scripting

D-WAQ # of yrs. – approx. 10 hrs. per year

total # of yrs. limited by D-FLOW with SED-ONLINE track

Vegetation biomass

Multiplied by Δt

Updated bathymetry & -

stratigraphy, using

vegetation biomass

Initial trachytopes Based upon bathymetry

Flowchart 2

Simple multiplication can go wrong due to physical limits and non-linear effects

Advised to explore the non linear behavior and the use of LaVeg results to limit the physical results

Landscape

Update

50 yrs 40 yrs 30 yrs 20 yrs 10 yrs

MODEL COUPLING FOR

PRODUCTION RUNS (SIMPLE)

• 50 year runs, Year 2020 – 2070

• Batch 1: seven production runs

Landscape

Update

Landscape

Update

Landscape

Update Landscape

Update

D-WAQ

D-FLOW-SED-ONLINE

Initial

Landscape

DELFT-3D MODEL DOMAIN AND

GRID

PROJECT TIMELINE

• Modeling Work: 18 months

Model Milestone Deadline

Project Begins March 2014

Data Collection Begins June 2014

Model Setup September 2014

Model Operational January 2015

Model Testing March 2015

Model Calibrated April 2015

Model Validated May 2015

Production Runs Begin (7 scenarios) June 2015

Production Runs End (7 scenarios) September 2015

Reports Submitted and Project Ends December 2015

S TA G E S TAT I O N AT M I S S I S S I P P I R I V E R

HD 2011 – STAGE RESULTS

HD 2011 – STAGE RESULTS

HD 2011 – STAGE RESULTS

HD 2011 – STAGE RESULTS

H D 2 0 11 – F L O W C O M PA R I S O N AT B E L L E

C H A S S E

BIAS CALCULATED: - 1 %

BIAS CALCULATION FOR STAGE

Station PBias (%)

Bonnet Carre -1.3 %

New Orleans - Carrolton +0.1 %

Belle Chasse -0.1 %

Alliance +0.3 %

W Point a La Hache -0.2 %

Empire -0.1 %

Venice -0.1 %

Head of Passes -0.4 %

OVERBANK FLOWS HIGH FLOW @ U/S = 1,100,000 cfs

Q-TO27 Model

(cfs) Q Ratings

(cfs) PBias (%)

Bohemia and Fort St. Phillip and

Ostra Lock (Overbank losses)

137,654 148,357 -7.2

Baptist Collete 106,612 103,966 2.5

Grand Pass & Tiger Pass 90,814 101,565 -10.6

West Bay 53,697 67,345 -20.3

Cubit's Gap 126,868 120,281 5.5

SW Pass 291,630 380,515 -23.4

South Pass 97,854 93,549 4.6

Pass-A-Loutre 71,468 73,419 -2.7

OVERBANK FLOWS MEDIAN FLOW @ U/S = 770,000 cfs

Q-TO27 Model (cfs) Q Ratings

(cfs) Bias (%)

Bohemia and Fort St. Phillip and

Ostra Lock (Overbank losses)

78,297 74,055 5.7

Baptist Collete 81,700 75,079 8.8

Grand Pass & Tiger Pass 65,642 75,927

West Bay 50,137 49,052 2.2

Cubit's Gap 89,471 83,343 7.4

SW Pass 253,491 263,200 -3.7

South Pass 84,395 69,499 21.4

Pass-A-Loutre 61,212 58,234 5.1

OVERBANK FLOWS AVERAGE FLOW @ U/S = 500,000 cfs

Q-TO27 Model (cfs) Q Ratings

(cfs) Bias (%)

Bohemia and Fort St. Phillip and

Ostra Lock (Overbank losses)

35,490 28,534 24.4

Baptist Collete 50,805 51,347 -1.1

Grand Pass & Tiger Pass 39,795 54,844 -27.4

West Bay 36,325 34,088 6.6

Cubit's Gap 57,353 52,975 8.3

SW Pass 176,023 166,720 5.6

South Pass 65,813 49,958 31.7

Pass-A-Loutre 47,562 35,257 34.9

• Suspended sediment transport rate at Belle Chasse

21

CALIBRATION FOR THE RIVER:

YEAR 2011

Suspended sediment transport rate at Bonnet Carre

22

C A L I B R A T I O N F O R T H E R I V E R :

Y E A R 2 0 1 1

VALIDATION FOR THE RIVER:

YEAR 2014

• Suspended sediment transport rate at Belle Chasse

23

MORPHOLOGIC CHANGE IN

CAERNARVON: YEAR 2011

24

Vertical Erosion/Accretion in 2011 (centimeter)

• Vertical Accretion (mineral+organic)

between 0.75 cm/yr. and 1.57 cm/yr (1996

to 2000, Lane et al. 2006)

• The model predicted vertical accretion

(mineral) in the year 2011 is approximately

1.71 cm/yr.

Source: Lake Pontchartrain Basin Foundation

MORPHOLOGIC CHANGE IN

CAERNARVON: YEAR 2014

25

Vertical erosion/accretion in 2014 (centimeter)

• Vertical Accretion (mineral + organic) between 0.75

cm/yr and 1.57 cm/yr (Day et al., 2009, Lane et al.

2006)

• The model predicted vertical accretion (mineral) in

the year 2014 is approximately 0.85 cm/yr.

• Land building is less in 2014: The diversion was not

in operation after March 2014

Source: Lake Pontchartrain Basin Foundation

Lower Breton

Mid-Breton

Lower Barataria

Mid-Barataria

Sediment

Diversions

CRMS sites

Source: CRMS

Likely flow conditions of four sediment diversions:

• ~35-75,000 CFS (~ 1,000-2,100 CMS)

POTENTIAL SEDIMENT DIVERSION

LOCATIONS

SEDIMENT DIVERSION

PRODUCTION RUNS (PR)

PR ID Description Operating Plan Design Discharge (cfs)

Sea Level

Rise Subsidence Rate

PR1 Mid-Barataria Less Aggressive 75K Intermediate 20% into range

FWOP/PR2 Future Without Project N/A (No Diversions)

N/A (No Diversions) Intermediate 20% into range

PR3 Mid-Breton Less Aggressive 35K Intermediate 20% into range

PR4 Lower-Breton Less Aggressive 50K Intermediate 20% into range

PR5 Lower-Barataria Less Aggressive 50K Intermediate 20% into range

PR6 All Four Diversions Less Aggressive 35K,50K,50K,75K Intermediate 20% into range

PR7 All Four Diversions Aggressive 35K,50K,50K,75K Intermediate 20% into range

PR8 Marsh Creation/Dredge Only N/A (No Diversions) N/A (No Diversions) Intermediate 20% into range

PR9 No Vegetation (20 yrs) Less Aggressive 35K,50K,50K,75K

Intermediate 20% into range

Less Aggressive = operation for 5 months

Aggressive = operation all year

PR8 = PR6 diversion footprints with sediment from 11 river bars

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

0

200,000

400,000

600,000

800,000

1,000,000

1,200,000

0 1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000

Sed

imen

t D

iver

sio

n D

isch

arg

e (C

FS

)

Mis

siss

ipp

i Riv

er D

isch

arg

e (C

FS

)

Hours

Less-Aggressive Operations

MISSISSIPPI RIVER

DAVIS POND

CAERNARVON

MID-BRETON

MID-BARATARIA

LOWER-BARATARIA

LOWER BRETON

OPERATION PLAN – LESS AGGRESSIVE

July

5th

Feb

20th

WATER LEVEL

MID BARATARIA OUTFALL AREA, YEAR 50

MBA: Mid Barataria

MBS: Mid Breton Sound

LBS: Lower Breton Sound

LBA: Lower Barataria

Note: Red Vertical Line represents annual end of

less aggressive operational schedule

Difference Between Future Without Project and 4 Diversions (Year 50)

WSE DIFFERENCE: PR6-PR2(FT)

DELFT: PR 6-PR2 DIFFERENCE

AT YEAR 50

LAND BUILDING

Organic Matter + Mineral Material

32

MRDM DELFT

LAND CHANGE - FWOP (YEAR 0-

50)

34

LAND BUILDING MAPS AT YEAR 50:

PR1

35

LAND BUILDING MAPS AT YEAR 50:

PR3

36

LAND BUILDING MAPS AT YEAR 50:

PR6

THANK YOU

301 NORTH MAIN STREET, SUITE 2000

BATON ROUGE, LA 70825

(225) 448-2813

WWW.THEWATERINSTITUTE.ORG

@TheH2OInstitute