How the STAC Phosphorous Review will Influence the CBP ...€¦ · How the STAC Phosphorous Review...
Transcript of How the STAC Phosphorous Review will Influence the CBP ...€¦ · How the STAC Phosphorous Review...
How the STAC Phosphorous Review will Influence the CBP Phase 6 CBWM
Gary Shenk EPA/CBPO
Presentation to STAC
12/3/13
Concepts
• State of the review
• Phase 6
• Incorporation method
• Possible formulations
• Who Decides
STAC P Review – Preliminary Findings
• Soil P concentrations and how we manage P applications are the major drivers for P losses that we can control.
• The simulation process needs to capture the impact of management on key drivers of P transport which will drive collection of essential data.
Additional Detail
• Inputs – Soil P reservoir – Overall P balance – Apply fertilizer and manure at times, rates, and method based
on regional information
• Processes – Soil Type-specific isotherms – Account for P stratification in CNT – Consider interaction between tillage and manure applications – Account for differences in connectivity that affect delivery
efficiency – Describe the temporal dynamics of the effects of drawdown of
soil P on loads – Be capable of scaling down to provide segment by segment
guidance on drivers of P losses and needed practices – Dissolved P!
The Bottom Line
• Collect or estimate Soil P levels
• Make export a function of application method
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Precipitation Fertilizer Manure Atmospheric deposition
Runoff
Phase 5
Hydrology submodel
Management filter
River Sediment submodel Phosphorus
submodel
Nitrogen submodel
hourly
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Precipitation
Fertilizer Manure Atmospheric deposition (…)
Runoff
Phase 6
Hydrology submodel
Management filter: Panels using multiple lines of evidence
River Sediment submodel
Nutrient Submodels
Temporal Nutrient model
What could submodels look like?
What could submodels look like?
What could submodels look like?
What could submodels look like?
Export Load =
Storage * Coeff (soil, slope, location, tillage)
+
Annual application * Coeff (parameters)
Alisha Mulkey and Frank Coale are working on a model like this
A STAC recommendation in this format could be readily implemented
Who Decides? • WQGIT – Ultimate responsibility
• Ag, Forestry, Urban Workgroups – Can make recommendations on land use types, loading rates, BMPs, or any other aspect of modeling.
• Land Use Workgroup – primary responsibility to determine land uses and methods to map them. Can make recommendations on loading rates.
• Modeling Workgroup – primary responsibility to determine calibration methods and multiple model averaging methods
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Chesapeake Bay Program Partnership
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Agriculture Workgroup BMP Verification Committee Forestry Workgroup Land Use Workgroup Milestones Workgroup Trading and Offsets Workgroup Urban Stormwater Workgroup Wastewater Treatment Workgroup Watershed Technical Workgroup
Modeling Workgroup 255
Model related Membership as of 7/2013 – 365 individuals
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Chesapeake Bay Partnership Models
Priorities
WQGIT Priorities for phase 6
15 Same is true for P processing, soils, etc
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Precipitation
Fertilizer Manure Atmospheric deposition (…)
Runoff
STAC recs fit here if they are clear and feasible
Hydrology submodel
Management filter: Panels using multiple lines of evidence
River Sediment submodel
Nutrient Submodels
Temporal Nutrient model
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Trees
Roots Leaves
Particulate
Refractory
Organic N
Particulate
Labile
Organic N
Solution
Ammonia
Nitrate
Solution
Labile
Organic N
Adsorbed
Ammonia
Solution
Refractory
Organic N
AGCHEM Nitrogen Cycle A
tmo
sph
eric
Dep
osi
tion
D
enit
rifi
cati
on
Export
Export Export Export Export Export Export
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PQUAL loading model
SURFACE
INTERFLOW
Groundwater
flow * conc sed * factor
flow * conc
flow * conc
Complex vs Simple
• Calibration is complex and time consuming
• Calibration is imprecise
• Longer run time
• Simulated sensitivity to inputs
• Calibration is relatively simple and fast
• Calibration is precise
• Shorter run time
• Sensitivity to inputs must be specified (by multiple research models and methods)
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-5%
0%
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25%
30%
35%
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0% 10% 20% 30% 40% 50% 60% 70%
Exp
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Atmospheric Deposition Reduction
Reduction in forest loads from 1985 to CAIR
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Aber, et al, 2003
-5%
0%
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30%
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0% 10% 20% 30% 40% 50% 60% 70%
Exp
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Atmospheric Deposition Reduction
Reduction in forest loads 1985 to CAIR
DE
DC
MD
NY
PA
VA
WV
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Regression of monthly nitrate yield – Preliminary Results
Deposition is Important in
the spring and fall
Disturbance is Important in the summer
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Sensitivity incorporation
1. Determine generalized sensitivity from AGCHEM
2. Literature / model search for sensitivities to input
3. Decision on sensitivity approach from the Modeling Workgroup
4. Implementation of sensitivity in the phase 6 model