application of the comprehensive aquatic system model
TRANSCRIPT
Application of the comprehensive aquatic system model(CASM-4D) in support of ecosystem restoration
Steven M. Bartell1,2
1Cardno, Inc., Greenback, TN2Department of Ecology and Evolutionary Biology,University of Tennessee, Knoxville, TN
• Describe the CASM• Introduce the SAND model• Present SAND-CASM integration
to address ecosystem restoration
Purpose
Special AcknowledgmentsCraig FischenichBobby McComasERDC, Vicksburg, MS forSAND modeling
Benthic Insects
Decomposers
Benthic Omnivorous Fish
Benthic InvertebratesPeriphyton
Macrophytes
Benthic PiscivorousFish
Planktivorous Fish
ZooplanktonPhytoplankton
Dissolved and Particulate
CarbonLight
NutrientsDINDIPSi
Piscivorous Fish
TemperatureDepthVelocitySalinityTISPOC, DOCDissolved O2 Emergents
Direct mortalityToxicity dataChemical concentrations
Comprehensive Aquatic Systems Model – CASM-4D
What is the CASM? How does it work?
Coastal Louisiana example
Spatial domain Modeled nodes
Each node
CASM-MRGOBartell et al. 2010 Food web is embedded
in each layer of eachnode
Photosynthesis, P
Sinking, S
Respiration, R
Mortality, M
Grazing, G
Phytoplankton
ΔB = P – (R + M + S) – G + (I - O)
Inflow, I Outflow, scour, O
Periphyton
Macrophytes
Emergentaquatic plants
Primary producer bioenergetics
Modeling aquatic plant populations
Biomass: gC/m2
Flows: gC/m2/d
Modeling fish and invertebrate populations
C
R,AU
GΔB = C - F - (R + A) - U - G - M - P
F
M,P
Biomass: gC/m2
Flows: gC/m2/d
Habitat quality effects on population-specific modeled growth
Producer habitat modifierHmod = F (hsalinity, hdepth, hvelocity)
Consumer habitat modifierHmod = F(hDO, hdepth, hsalinity, hvelocity)
For each species, node, and time step:dB/dt = r Hmod B,
where, r is the overall growth rate determinedby the bioenergetics
0
1.0
h (F)
Factorx1 x2 x3 x4
x1 = lower thresholdx2-x3 = optimal rangex4 = upper threshold
Environmental inputs define habitat quality and distribution
Biological/EcologicalDaily values of population biomass (gC/m2)Community diversitySystem-level N and P assimilationOxygen producedCarbon sequestration
EnvironmentalDissolved oxygenDIN, DIP, Si, TIS, POC, DOC
Ecological RisksPopulation, community, ecosystem effects
CASM-4D Outputs
SAND V3: Sediment And Nutrient Diversion Model - Planform
Point of discharge
10 km
20 km
Sediment accumulation• Discharge, velocity• Suspended sediment concentrations• Particle size• Roughness
Example has 50 spatial zones across the model domain
SAND V3: Sediment And Nutrient Diversion Model
At+1 = At + δAt + Ased
where,At+1 = marsh area at t+1At = marsh area at tδ = percent change due to sea-level rise, erosion,
subsidenceAsed = benefit to marsh area of adding sediments
Example SAND input river discharge – 25 y
• Daily discharge • Suspended sediment load• Nutrient concentration
SAND annual sediment deposition (feet) – selected zones
• Depends upon discharge, velocity, particle size, bathymetry,and sediment consolidation
• Value of zero means maximum amount of land-building achieved for the zone
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
8 16 24 32 40 48
Mean depth (m) - initialMean depth - final (m)
Node
SAND modeled changes in mean zone depth – after 25 y
Zone
SAND V3 CASM-4D
Water depth
Percent land
Dissolvedinorganic N
Initial conditions:• Land cover • Bathymetry
Daily values:• Discharge• Suspended sediments• Nitrogen
Distribution and biomass:
Aquatic plants
Aquatic invertebrates
Fish
Risks and benefits of ecosystem restoration
Use an integrated modeling approach to examineecological implications of sediment management
SAND-CASM modeled changes in aquatic plants – entire domain
-30
-20
-10
0
10
20
30
40
50
4 8 12 16 20 24
PhytoplanktonPeriphytonSAVEmergent aquatic plants
Year
Results reflect• Population-specific depth preferences• Population-specific responses to DIN loading• Overall increase of land-cover, less open water
SAND-CASM modeled changes in benthic invertebrates – entire domain
0
10
20
30
40
50
4 8 12 16 20 24
OystersBlue crabBrown shrimpWhite shrimp
Year
• Population-specific depth preferences• Indirect food web effects ,
e.g., increased periphyton production
0
1.0
h (F)
Factorx1 x2 x3 x4
Relevance to GEER:
• Managed flows• Beneficial sediment use• Temperature• Salinity• Nutrients (N, P)• Combined factors
Governing equations
Aquatic plants
Fish and invertebrates
• First-order linear differential equations with nonlinear terms• One instance of the governing equation for each population• Equations interrelated by trophic interaction terms
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Integration of CASM-4D with physical models
Hydrodynamic and Hydraulic Model Outputs- depth- current velocity- suspended sediments- temperature- salinity
time seriesof inputvalues
CASM-4D
Scale differences between H&H modelsand CASM routinely requires somespatial and or temporal averaging…
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