Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top...
Transcript of Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top...
![Page 1: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/1.jpg)
Modeling … What’s the Use?PaulMcGinley
CenterforWatershedScience&EducationUWStevensPoint
Lake Leaders 2016
![Page 2: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/2.jpg)
What’samodel
Onedefinition:Amathematicaldescriptiontohelpvisualize something
helpus“visualize”acurrentconditiontobetterunderstanditorhelpus“visualize”howfutureactionscouldalterthecurrentcondition
• Examples– How long does water spend in my lake?– If a wooded area is converted to row crops, what might
that do to the phosphorus concentration in the lake?
![Page 3: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/3.jpg)
Today….1)Watershedsand2)Lakes&3)Streams
• Functioning– bigpicturearmwaving– &thedevelopmentof“Conceptual”Models
• Takeusthroughacoupleexamples• Endwithbriefdiscussionofothermodels
Goal- Understand & Apply several Models
(and most important… not make a potentially confusing topic more confusing…)
![Page 4: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/4.jpg)
First– Watersheds
Define- that area where the water drains to the outlet point of interest
![Page 5: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/5.jpg)
Define- that area where the water drains to the outlet point of interest
allofthelandsurfacebelongstoa“watershed”
![Page 6: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/6.jpg)
Our Watershed interests might be…--- Water, Sediment & Nutrients (could be others)
![Page 7: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/7.jpg)
Precipitation = ___ inches/yr
Event FlowBaseflow
Evapotranspiration = ___ inches/yr
![Page 8: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/8.jpg)
Precipitation = 32 inches/yr
Event FlowBaseflow
Evapotranspiration = 22 inches/yr
![Page 9: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/9.jpg)
Precipitation = 32 inches/yr
Event FlowBaseflow
Evapotranspiration = 22 inches/yr
Watershed“Runoff”
= ___ inches/yr
![Page 10: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/10.jpg)
Precipitation = 32 inches/yr
Event FlowBaseflow
Evapotranspiration = 22 inches/yr
Watershed“Runoff”
= 10 inches/yr
![Page 11: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/11.jpg)
Precipitation = 32 inches/yr
Event FlowBaseflow
Evapotranspiration = 22 inches/yr
Watershed“Runoff”
= 10 inches/yr
10 inches /year on 1 square mile…= 23,000,000 cubic feet /year!
![Page 12: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/12.jpg)
Precipitation = 32 inches/yr
Event FlowBaseflow
Evapotranspiration = 22 inches/yr
Watershed“Runoff”
= 10 inches/yr
10 inches /year on 1 square mile…= 23,000,000 cubic feet /year!= 0.7 cubic foot every second!
![Page 13: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/13.jpg)
Thisisawatershedmodel!
• WaterBudget
LakeGroundwater
Surface Runoff
Precipitation - Evaporation
Outflow
(10 in/year)*(Watershed Area)Water Entering theLake Each Year =
![Page 14: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/14.jpg)
Rule#1
“Allmodelsarewrongbutsomeareuseful”GeorgeBox
![Page 15: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/15.jpg)
Wrong
• Year-to-YearVariations• Differentpartsofthewatershedhavedifferentresponse– Impervioussurfaces– Compactedsoil– Exposedsoil/raindropimpact
![Page 16: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/16.jpg)
• Useful?–Residencetime==AmountofWaterinLakeRateWhichWaterLeavesLake
![Page 17: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/17.jpg)
• Useful?–Say10,000acrelake,meandepthof40feetwitha150,000acrewatershed
–Residencetimeestimate==(10,000acre)(40feetmeandepth)
(150,000acre)(0.83ft/yr)=3.2years
![Page 18: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/18.jpg)
Howcanweimprovethismodel?
• Refinefordifferentareas• Lookatstormintensity,patterns,soilmoisture• Simulateeachyear…oreachday…
• Ofcoursethiscomesatacost…isitnecessary?Isitworthit?
![Page 19: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/19.jpg)
22”
32”
10”
Land
ModelingtheLand?
Very Simple Very Complex
AnnualVolume
Follow Every drop
![Page 20: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/20.jpg)
22”
32”
10”
Land
ModelingtheWateronLand?
Very Simple Very Complex
AnnualVolume
Follow Every drop
AnnualBut
Divideby
Landuse
HourlyRainfall
VaryBy
Area
Daily TimeStep
SpatialLumping
Separate AnnualGroundWater
& Surface Runoff
![Page 21: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/21.jpg)
CloselyRelated…NutrientMovement
• Justtalkedaboutwatermovementonland
• Next…NutrientLossfromLand
![Page 22: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/22.jpg)
Let’slookatPhosphorusMovement
• ImportantImplicationsforLakes&Streams
• Oligotrophic- “few”“foods”• Eutrophic– “many”“foods”
http://www.secchidipin.org/trophic_state.htm
![Page 23: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/23.jpg)
45,000 lb plant P50,000 lb organic matter P250,000 lbs soil P (top 6”)
350,000lb P
/sq mileAdapted from Yanai, R.D., 1992. Phosphorus Budget of a 70-year-old northern hardwood forestBiogeochemistry 17:1-22
Whereisthephosphorus?
![Page 24: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/24.jpg)
• WaterAcrossLand=PhosphorusintheWater
![Page 25: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/25.jpg)
ATaleofTwoPathways(and, how we go from rainfall to runoff volume w/ phosphorus concentration to lbs/acre-year)
2inch/year@1
mg/l=0.45lb/acre
/year
(+9inch/yr @0.02mg/l)
10inch/[email protected]/l<
0.01lb/acre/year
![Page 26: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/26.jpg)
“PhosphorusExportCoefficients”(pounds/acre-year)
Low MostLikely HighAgriculture(Mixed)
0.3 0.8 1.4
MedDensityUrban
0.3 0.5 0.8
Pasture 0.1 0.3 0.5Forest 0.05 0.09 0.18
Atmospheric(lakesurface)
0.1 0.3 0.5
Adapted from WiLMS, Wisconsin Lake Modeling Suitehttp://dnr.wi.gov/lakes/model/
![Page 27: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/27.jpg)
Useful…backtoour150,000acrewatershed• EstimatethelongtermaveragePtransferfromawatershedtothelake– 90,000acresRowCrop
• 90,000ac*0.8lb/ac-year=72,000lbs/year– 30,000acresPasture/Grass
• 30,000ac*0.3lb/ac-year=9,000lbs/year– 30,000acresMedDenUrban
• 30,000ac*0.5lb/ac-year=15,000lbs/year
– TOTAL=96,000lbs/year– USEFUL?
![Page 28: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/28.jpg)
Ofcourse,thisisasimplification:AnnualVariationsinPtoLake!
• PLoad(lb)toLake(LathropandPanuska)
![Page 29: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/29.jpg)
Howaboutanotherimportantlandmodification….
RiparianDevelopment
![Page 30: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/30.jpg)
RiparianDevelopment
Changestophosphorusmovement?– Changesinvegetation
• Interception• Evapo-transpiration
– Changesininfiltration• Compaction
– Changesinrunoffgeneration• Sourcesofrunoff• Pathwaysittakes
– Changesinnutrientavailability• Fertilizer• Vegetation
![Page 31: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/31.jpg)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 10 20 30 40 50 60 70
Percent Impervious
Phos
phou
s Ex
port
(lb/
acre
-yr) Panuska, 1994
SLAMM ApproachStearns Co MNUWSP Long Lake
RIPARIAN MODEL OUTPUT EXAMPLE4% to 5% slope/Silt Loam or Silty
![Page 32: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/32.jpg)
Whataboutcompaction?
ConditionPonded
Infiltration Rate (in/hr)
Vegetated 3.4
Open Soil 0.7
Traffic 0.1Silt loam soil described by Vervoort, R.W., S.M. Dabney and M.J.M. Romkens. 2001. Tillage and Row Position Effects on Water and SoluteInfiltration Characteristics, Soil ScienceSociety of America Journal 65:1227-1234.
Factors Controlling Water Movement
![Page 33: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/33.jpg)
0
0.5
1
1.5
0.01 0.1 1 10Infiltration Rate (in/hr)
Frac
tion
of R
unon
Tha
t R
uns
Off
1.3"
0.1"
0.25"
0.5"
Thefractionofrunon tothesecondarybufferthatwouldinfiltratefordifferentstormsizesandinfiltrationrates(assumesa500ft2imperviousareadrainingtoafivefootwidechannel,fortyfeetlongandonehourstormofdepthshown).Dashedlinesshowthefittedequationbasedonsoilinfiltrationrateandstormdepth.
Runon Ratio500 / 5(w) x 40 (L)
¼ - ½ inch/hour
SANDYSILTYCLAYEY
AnotherModel….RunofffromanimperviousareaontoaperviousslopeShorttime-step,rain,runoff,flowacrossinfiltrationsurface!
![Page 34: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/34.jpg)
22”
32”
10”
Land
ModelingtheLand?
Very Simple Very Complex
AnnualVolumexAverageConcentration
Follow Every drop
Annual ExportBased onLanduse
ShortTimeStep
SpatiallyVariable
Daily TimeStep
SpatialLumping
Avg.Annual
Spatially Variable
![Page 35: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/35.jpg)
Part2- LAKES
![Page 36: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/36.jpg)
Zooplankton
Bacteria
WATER
Algae
FISH WaterQuality
N U T R I E N T S
• Important• Butwhatdowewanttomodel?
– Waterlevel,Algaldensity,Fish,PhosphorusConcentration• Complex?
![Page 37: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/37.jpg)
OurFirstModel
• Goal– predictthePconcentration
Given• TheamountofPenteringthelake• Theamountofwaterenteringthelake
![Page 38: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/38.jpg)
PhosphorusEntering
Phosphorus leavingIn water
Concentration = Phosphorus/Water
WaterEntering
~Mix~
![Page 39: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/39.jpg)
Let’sgivethisatry
• 10,000acrelake• 150,000acrewatershed
Recalloursimplewatershedmodel…• 96,000lb/yearP• 125,000acre-ft/yearwater
PhosphorusEntering
Phosphorus leavingIn water
WaterEntering
![Page 40: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/40.jpg)
“SimpleModel”(annualP/annualwater)
• ConcentrationofP
=MassofP/VolumeofWater
=96,000pounds/23,000,000cubicfeet=285ug/l
![Page 41: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/41.jpg)
Takealookatsomedata
Lathrop and Panuska 1998
285 ug/l
![Page 42: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/42.jpg)
Notaverygoodmodel
• Why?
• WhathappenstoPinalake?
• Anotherobservationonmodeling– “Everythingshouldbemadeassimpleaspossible,butnosimpler”A.Einstein
![Page 43: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/43.jpg)
SecondModelPhosphorus
Entering
Phosphorus leavingIn water
Phosphorus “settling”In lake
WaterEntering
“diminished by retention term as P apparently lost to sediments” (Nurnberg, 1984)
![Page 44: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/44.jpg)
Uniform(“steady-state”)ConditionsThePconcentrationdoesn’tchangewithtimeTheamountofPinthelakeisconstant
vAQMCP +
=
Phosphorus Concentration in Lake
Mass of Phosphorusper year entering lake
Amount of waterEntering lake in a year Settling term
(“settling velocity” * Area
With this added
![Page 45: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/45.jpg)
Let’sgivethisatry
• 10,000acrelake• 150,000acrewatershed
Assume• 96,000lb/yearP• 125,000acre-feetwater/year• 40,500,000m2lakesurface• 10meter/yearsettlingvelocity
PhosphorusEntering
Phosphorus leavingIn water
WaterEntering
![Page 46: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/46.jpg)
Our“LessSimpleModel”
• ConcentrationofP
=108ug/l(better?)
• Useful?
![Page 47: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/47.jpg)
Useful?
![Page 48: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/48.jpg)
AnnualPhosphorus
Input
AnnualWaterInput
AnnualPhosphorusSettling
SimplerModels…--completelymixed-- steadywithtime
ComplexModels…--segmentsinlake--varywithtime--biology!
Ofcoursethisisstillasimplemodel…
![Page 49: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/49.jpg)
OtherModels
• Variationsinmovementofwater– Stratifiedlake– Segmentedlake– Groundwaterflowmodels– Icecoveredlake…warming--density!
“Hydrodynamic Models”“One-Dimensional, Two-D, Three-D”
![Page 50: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/50.jpg)
OtherModels
• VariationsinChemistry(P,other)overtime/space– Dailyorhourlymodels– Segmentedlakemodels– Dissolvedoxygen– Calciumcarbonateformation(“Marl”)– Sedimentrelease
“Transient Models”“Spatially Variable Models”“Chemical Models”
![Page 51: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/51.jpg)
PhosphorusConcentration Algal
Concentration
LakeResponseModel?
![Page 52: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/52.jpg)
• Useful?
![Page 53: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/53.jpg)
Increasing interest in food web models
![Page 54: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/54.jpg)
Discussion
• Watershed– WaterBudget– PhosphorusBudget
• Lake– Concentrations– Response– Other…
• Simple– ReduceSpatialVariations
– LongTermAverages
• Complex– TimeandSpaceVariations
– Daily/YearlyVariations
![Page 55: Modeling … What’s the Use? - UWSP€¦ · 50,000 lb organic matter P 250,000 lbs soil P (top 6”) 350,000 lb P /sq mile Adapted from Yanai, R.D., 1992. Phosphorus Budget of a](https://reader033.fdocuments.in/reader033/viewer/2022042417/5f3291ebe375836da44e78cb/html5/thumbnails/55.jpg)
QuestionsPaul McGinleyUW-Stevens [email protected](715) 346-4501