SWAT v. BayFAST: An Inter-model Comparison · 2019. 7. 19. · Nutrient TMDL CNS SWAT WIP BayFAST...
Transcript of SWAT v. BayFAST: An Inter-model Comparison · 2019. 7. 19. · Nutrient TMDL CNS SWAT WIP BayFAST...
SWAT v. BayFAST: An Inter-model Comparison
Rashmit Arora
What is BayFAST?
• The Bay Facility Assessment Scenario Tool (BayFAST) is a web-based nitrogen, phosphorus and sediment load estimator that is intended to streamline environmental planning
• Users specify the boundaries of a parcel, and then select BMPs to apply on that parcel
Inter-model Comparison Scenarios
• 2012 Baseline
• Watershed Implementation Plans (WIP, Bay program version)
• WIP, CNS SWAT version
BMP list• DryPonds
• EandS
• EffNutMan
• ExtDryPonds
• Filter
• ForestBuffers
• ForestBuffersTrp
• ForestBufUrban
• ForHarvestBMP
• GrassBuffers
• GrassBuffersTRP
• HorsePasMan
• ImpSurRed
• Infiltration
• LaggonCovers
• LandRetireHyo
• LandRetirePas
• MortalityComp
• NonUrbStrmRest
• PoultryInjection
• PoultryPhytase
• PrecRotGrazing
• Septic
• StreetSweep
• SwinePhytase
• TreePlant
• UpPrecIntRotGraze
• UrbanNMPlan
• UrbanTreePlant
• UrbGrassBuffers
• UrbStrmRest
• WetPondWetland
• AbanMineRec
• Alum
• AWMS
• BarnRunoffCont
• CaptureReuse
• CarSeqAltCrop
• ComCovCrop
• ConPlan
• ConserveTillTotAcres
• ContinuousNT
• CoverCropEOW
• DirtGravelDSA
▪ BMPs in CNS SWAT scenario▪ BMPs in CNS SWAT not
available in BayFAST▪ BMPs in Bay program WIP
scenario▪ BMPS in Bay program WIP not
available in BayFAST
SWAT vs. BayFAST
Nutrient TMDL CNS SWAT WIPBayFAST WIP, CNS SWAT
Iteration BayFAST WIP, Bay Iteration
Total N 25.0 12.0 11.0 20.9
Total P 25.0 15.0 0.5 16.6
Sediment 30.0 41.0 12.1 24.5
Conewago Creek
*all numerical values are percentage reductions in the loads delivered to the Bay
Nutrient TMDL CNS SWAT WIPBayFAST WIP, CNS SWAT
Iteration BayFAST WIP, Bay Iteration
Total N 25 25.6 11.0 24.3
Total P 25 12.2 3.9 20.4
Sediment 30 23.3 8.6 24.7
Mahantango Creek
SWAT vs. BayFAST
*all numerical values are percentage reductions in the loads delivered to the Bay
Animal heavy use areas
• Amish Farm Study
– The tests took place over a period of two years
– Saw various configurations of filtration systems employed in order to abate runoffs
– 35 kg of phosphorous entered the treatment system over the first year, followed by a lesser load of 12.6 kg over the second year
→ The detention basin, paired with a flow control structure, removed a tremendous amount of phosphorous -16kg over the two years.
→ The slag filters removed 4.7 kg of phosphorous over the two years
Land Use Loads (sorted for P)
Sector Landuse NLoadDEL (lbs) PLoadDEL (lbs) SLoadDEL (lbs)
Agriculture animal feeding operations 42808.6 2374.9 10089.6
Agriculture lowtill with manure 169027.4 1079.7 1119117
Agriculture concentrated animal feeding operations 12588.1 698.4 2975.3
Agriculture pasture 2527.5 512.2 52078.2
Urban regulated impervious developed 33337.3 438 349299.2
Sector Landuse NLoadDEL (lbs) PLoadDEL (lbs) SLoadDEL (lbs)
Agriculture animal feeding operations 121030 7412.7 44500.7
Agriculture lowtill with manure 377463.8 4080.5 5721761
Agriculture hightill with manure 236719.9 1813.2 4712940
Urban nonregulated extractive 48134.1 1373.6 2387112
Agriculture nursery 29965.7 1334.7 63530.7
Conewago Creek
Mahantango Creek
Animal BMP Scenarios
• 2012 Baseline
• 100% Animal BMPs on AFOs and CAFOs
• 50% Animal BMP, improved WIP (reduced agricultural BMPs)
• 50% Animal BMP, improved WIP (reduced urban BMPs)
100% Animal BMP ScenariosBMP Watershed N (%) P (%) Sed (%) Cost ($)
Loafing Lot Management Conewago 1.9 8.1 0.2 $57,093
Loafing Lot Management Mahantango 1.9 7.3 0.1 $145,650
Loafing Lot Management Spring Creek 0.3 1.1 0.3 $197,315
BMP Watershed N (%) P (%) Sed (%) Cost ($)
Barnyard Runoff Control Conewago 1.9 8.1 0.2 $13,605
Barnyard Runoff Control Mahantango 1.9 7.3 0.1 $34,697
Barnyard Runoff Control Spring Creek 0.3 1.1 0.3 $47,019
BMP Watershed N (%) P (%) Sed (%) Cost ($)
AWMS Livestock Conewago 1.9 7.5 0 $77,301,883
AWMS Livestock Mahantango 1.5 4.9 0 $10,153,555
AWMS Livestock Spring Creek 1.3 4.4 0 $11,103,814
BMP Watershed N (%) P (%) Sed (%) Cost ($)
AWMS Poultry Conewago 4.4 25.2 0 $7,444,525
AWMS Poultry Mahantango 6 23.8 0 $1,893,987
AWMS Poultry Spring Creek 0 0 0 $157,604
Cost Effectiveness Tables
Nitrogen Phosphorous Sediment
BMPCost Effectiveness
($/lb reduced) RankCost Effectiveness
($/lb reduced) RankCost Effectiveness
($/lb reduced) Rank
Conservation Tillage $0.00 1 $0.00 1 $0.00 1
Continuous No-Till $0.00 2 $0.00 2 $0.00 2
Carbon Sequestration and Alternative Crops $66.76 3 $38.02 5 $46.64 6
Conservation Plans - High-till $83.66 4 $20.88 3 $15.01 4
Conservation Plans -Pasture $133.86 5 $31.32 4 $26.81 5
Water Control Structures $181.61 6 - 76 - 76
Ammonia Emissions Reduction - Biofilters $198.70 7 - 43 - 40
Conservation Plans - All Hay $223.10 8 $62.63 6 $46.91 8
Conservation Plans - Low-till $223.10 9 $62.63 7 $46.91 9
Ammonia Emissions Reduction - Alum $238.44 10 #VALUE! 42 #VALUE! 39
50%, Improved WIP Scenario
N P S Cost
20.9 16.6 24.5 $9,778,673
Cost Induced
$939,148
N P Sed Cost
23.7 26.7 24.5 9,699,967
N P Sed Cost
24.3 27.4 25 9,702,543
Bay WIP 50% more AWMS-P
50% more AWMS-P, reduced Alum, AWMS-L
50% more AWMS-P, reduced Dry Extended Ponds
Mahantango Creek
N P S Cost
23.2 26.9 24.5 $10,717,821
Lessons learned
• Approach planning/modeling with caution, understand how different models function and where their biases lie
• Rethink WIPs in terms of cost effectiveness of BMPs
• Increased focus on animal heavy use areas