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This publication highlights the importance of careful water management including urban water conservation, particularly along the Wasatch front and in high growth areas of Utah.
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Verification of Turfgrass Evapotranspiration in Utah
Prepared by Robert W. Hill and J. Burdette Barker
VERIFICATIONOFTURFGRASSEVAPOTRANSPIRATION
INUTAH
FinalReport
PerformancePeriodJuly18,2001–June30,2008
Submittedto
UtahDepartmentofNaturalResourcesDivisionofWaterResources
UtahAgriculturalExperimentStation StateofUtahProjectNo.797/789 ContractNo.01‐1995UtahStateUniversityControlNo.01‐1294
Preparedby
RobertW.HillandJ.BurdetteBarker
ProfessorandExtensionIrrigationSpecialistandStudentAssistantBiologicalandIrrigationEngineering
UtahStateUniversityLogan,Utah84322‐4105
Mentionofatrademarknameorproprietaryproductdoesnotconstitute
endorsementbyUSUanddoesnotimplyitsapprovaltotheexclusionofotherproductsthatmayalsobesuitable
UtahAgriculturalExperimentStationResearchReport#211
July8,2010
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EXECUTIVESUMMARYVerificationofturfgrassconsumptiveusewasaccomplishedwithfieldstudiesgenerallyduring2002‐2008infourareasofUtah:CacheValley(LoganGolfandCountryClub),SaltLakeCounty(MurrayParkwayGolfCourse),UtahCounty(BrighamYoungUniversity[BYU]SpanishForkFarm2002‐06)andWashingtonCounty(SunbrookGolfCourse,2002‐06andSouthgateGolfCourse,2004‐08).TwolysimeterswereinstalledateachofthethreesitesoutsideCacheValleyinlate2001andearly2002.TheexistingtwolysimetersinLogancontinuedtobeused.InApril2004athirdlysimeterwasinstalledatLoganandtwolysimeterswereinstalledatSouthgateGolfCourseinSt.George.Irrigationandrainaswellasdrainageweremeasuredateachlysimeteratintervalsduringthegrowingseason.Wateruseoftheturfgrasswassetequaltothedifferencebetweenmeasuredirrigationandrainfallandtheamountofdrainagewater.WeatherdataforusewithaPenmancombinationtypeETequationwascollectedwithelectronicweatherstations(CampbellScientific,Inc.)ateachsite.Cropcoefficientswerecalculatedastheratioofturfgrasswaterusetoalfalfareferenceevapotranspiration(ETr)calculatedwiththeASCEStandardizedPenman‐MonteithETequation(denotedasETrs).Observedseasonalturfgrassconsumptiveusevariedfrom11.2inches(LoganWest,2004,)to50.0inches(Southgate,2007).TherangeatLoganwas11.2(West,2004)to35.2inches(new,2007);atMurray,22.2(East2008)to30.5inches(East2005);atSouthgate,19.7(East2006)to50.0inches(West2007);atSpanishFork),14.2(South2002)to30.4inches(North2004)and13.0(East2004)to35.5inches(West2002)atSunbrook.DirectcomparisonofsuchvariationinETvaluesacrossyearsandsitesisproblematicduetodifferinggrowingseasonlengthsfromyeartoyear,siteenvironmentalconditions(averagetemperaturesandwindpatterns),andelevation(rangeof2600to4800ftabovemsl)fromsouthtonorthinUtah(latituderangeof37°Nto42°N).Themulti‐yearaverageseasonalobserved(basedonlyonindividuallysimeterET)cropcoefficientvaluesvariedfrom0.34(LoganWest)to0.65(SouthgateWest).StudyperiodaverageseasonalKcvaluesbylysimeterwere:Logan0.59(new),0.42(east),0.34(west)andsiteaverageof0.45;Murray0.57(botheastandwest)andsiteaverageof0.57;Southgate0.53(east),0.65(west)andsiteaverageof0.59;SpanishFork0.58(north),0.54(south)andsiteaverageof0.56andSunbrook0.49(east),0.46(west)andsiteaverageof0.47.AveragetwolysimeterseasonalKcvaluesatMurrayandSpanishForkweresimilar(0.57and0.56,respectively)althoughtherewaslessacrossyearvariationatSpanishFork.Analfalfareference(ETr)basedseasonalaveragecropcoefficient,Kcr,valueofabout0.60reasonablyrepresentsawellwateredturfgrass,cuttingheightof1.5to2inches,inthecentralandnorthernpartsofthestate,whereasaKcrof0.65wouldsimilarlybereasonabletouseinthelowerelevationandwarmersouthernUtah’sDixie.TheseKcrvalues,0.60and0.65,are,respectively,about7%and16%higherthantheKcrof0.56usedinearlierestimatesofturfgrassevapotranspirationacrossUtah(Hill,1994).
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MonthlyKcr,andsubsequentlygrassreferencebasedKco,valueswerederivedforfourofthelysimeters:Logan–new,SpanishFork–north,andbothSouthgatelysimetersbyproratingobservedlysimeterETbetweenadjacentmonthsusingthenumberofdaysinthemeasurementinterval.FurtherdataadjustmentsweremadeuponfinalanalysisbydiscardingobviousoutliersfromtheaveragemonthlyKcvalues.Themonthlycropcoefficient,Kcr,forthehigherelevationnorthernmajorityofUtahbeginswithavalueof0.45startingatturfgreenupandremainsat0.45forabout20daysuntiltheturfbeginsactivegrowth.TheKcrvaluethenincreaseslinearlyoverabout30daystoavalueof0.60whentheturfreachesfullandgrowth.TheturfKcrremainsat0.60forthedurationoftheseasonuntilcoolfalltemperaturesresultinreducedturfgrowthrates.Thisistypicallyaroundmid‐October,afterwhichKcrdecreaseslinearlytoward0.45inearlyNovemberandremainsatthatvalueuntildormancy.ThemonthlyKcrcurveforlowerelevationsouthernUtahissimilar;however,itcontinuesforthefullyearbeginninginJanuaryatavalueof0.50duringthesemi‐dormantperiod.InlateFebruarytoearlyMarchtheKcrvaluebeginstoincreaselinearlyovera30dayperiodtoavalueof0.65,andremainsat0.65forthemajorityoftheseasonuntilthegrowthslowsinmidtolateOctober.TheKcrvaluethendecreaseslinearlytoavalueof0.50,typicallyreachedinmidNovemberandremainsat0.50untilthefollowingspring.Inbothsetsofsuggestedcropcoefficientcurves,maintainingthemid‐seasonKcrataconstantvalue,0.60or0.65,ignorestheindicationofa“summerslump”inturfwateruse.Grassreferencebasedcropcoefficient,Kco,valueswerederivedfromKcrbymultiplyingKcrbyabout1.2.Thus,mid‐seasonKcovaluesof0.70fornorthernUtahandhigherelevationsand0.80forsouthernUtahandlowerelevationswereobtainedbyroundingtothenearest0.05.CorrespondingearlyandlateseasonKcovaluesare0.50and0.60,respectively,fornorthernhigherelevationandsouthernlowerelevationUtah.
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ACKNOWLEDGEMENTS
TheworkdescribedhereinwasperformedunderacontractbetweentheUtahDepartmentofNaturalResources,DivisionofWaterResourcesandUtahStateUniversity(DepartmentofBiologicalandIrrigationEngineering[BIE]).ThiscontractwasinitiatedinJuly2001toperformfieldresearchusinglysimetersatselectedUtahlocationstoverifypreviouslyusedconsumptiveuse(evapotranspiration)factorsforturfgrass.ThecontractwasoriginallyexpectedtoendJune30,2005.However,theterminationwasextendedthroughJune30,2008toallowcollectionofthreeadditionalfullyearsofdata(2005‐2007)onthenew(April2004)lysimetersatLoganandSouthgate.Subsequently,anadditionalyear(2008)ofdatawascollectedatLogan,MurrayandSouthgateandisincludedherein.Gratitudeisexpressedtothefollowingindividualswhocollectedfielddatafrom2002–2008:DavidCarruth,MurrayParkwayGolfCoursesuperintendent;EarlHansen,BYUAgronomyDept;RickHeflebower,WashingtonCountyExtensionagent;JulieBreckenridge,WashingtonCountyWaterConservancyDistrict;SergioSolis,SunbrookGolfCoursesuperintendent;ConradBarrow,SunbrookGolfCourse;SherrieFox,SouthgateGolfCourseandUSUBIEstuentsBurdetteBarker,MusaDlamini,DarrenFillmore,WesleyHopwoodandRyanMcBride.Musa,Ryan,Darren,MichaelKohlerandOmarAlminagortaprovidedvaluableanalysisofseasonallysimeterandweatherdataforannualreports.Burdetteprovidedconsiderableassistancewiththefinalreport.TheassistanceofNancyHanks,AllisonBarnes,KellyMcKee,MeganPoulton,andShelleyComendant,USUBIEstaffassistantsisappreciatedfortheirhelpinpreparingthevariousannualreports.ParticulargratitudeisextendedtoRebecaOlsenforherwordprocessingandeditingskillsincompletingthefinalreport.
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TABLEOFCONTENTS
ExecutiveSummary........................................................................................................................ ii
ACKNOWLEDGEMENTS ................................................................................................................. iv
VERIFICATIONOFTURFGRASSEVAPOTRANSPIRATIONINUTAH...................................................1
INTRODUCTION.........................................................................................................................................................1EvapotranspirationEstimation .................................................................................................................................3
PROCEDURES..................................................................................................................................6
LysimeterTechniquesforMeasurementofTurfgrassWaterUse ............................................................................6FIELDPROCEDURES(DATACOLLECTION)..................................................................................................................9
WeatherDataCollection ......................................................................................................................................9SiteDescriptions.................................................................................................................................................11
DataAnalysis...........................................................................................................................................................14RESULTSANDDISCUSSION……………………………………………………………………………………………………..17
ObservationandCalculationPeriods .................................................................................................................17WeatherDataAdjustmentsandCalculatedReferenceEvapotranspiration ......................................................19LysimeterWaterBalanceandCalculatedKcrValues...........................................................................................23EstimatedMonthlyTurfgrassCropCoefficients.................................................................................................33
SUMMARYandCONCLUSIONS.....................................................................................................41
REFERENCES .................................................................................................................................43
APPENDICES .................................................................................................................................45
APPENDIXA:WorkTasksbyObjective ..................................................................................................................45APPENDIXB:TurfLysimeterDataCollectionProtocol...........................................................................................46APPENDIXC:Weatherstationsensorsandobservationparameters ....................................................................49APPENDIXD:SummaryofDataCollectedatLogan,1991‐2001............................................................................50APPENDIXE:CorrectionsMadetoWeatherData .................................................................................................52APPENDIXF:AdjustmentsMadetoIndividualLysimeterDrainageValuesDuetoOvertopping ..........................54
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ListofTablesTable1:INstallationdatesanddepthoflysimeters.....................................................................................................8
Table2:CoordinatesandElevationsofElectronicWeatherstationsatTurfLysimeterSitesinUtah .......................10
Table3:Availablewatercontentandinitialsoilwatercontentsusedinthesoilwaterbalancemodel ...................16
Table4:LoganGolfandCountryClubbeginningandendingdatesfordataCollectionandcalculationperiods......17
Table5:MurrayParkwayGolfCoursebeginningandendingdatesfordatacollectionandcalculationperiods ......18
Table6:SouthgateGolfCoursebeginningandendingdatesfordatacollectionandcalculationperiods ................18
Table7:SpanishForkbeginningandendingdatesfordatacollectionandcalculationperiods................................19
Table8:SunbrookGolfCoursebeginningandendingdatesfordatacollectionandcalculationperiods .................19
Table9:SolarRadiationCalibrationFactorandETrCalculationTimestepforEachSiteandYearatUtahTurfLysimeterSites,2002‐2008. ...............................................................................................................................20
Table10:ComparisonofDailyandHourlyCalculatedETrsValueswithandwithoutWindAdjustmentsforeachSiteandYearatUtahTurfLysimeterSites,2002‐2008.............................................................................................22
Table11:LoganGolfandCountryClubNew,EastandWestLysimeterFullSeasonWaterBalanceValueswithSeasonalCalculatedCropCoefficients ...............................................................................................................28
Table12:MurrayParkwayGolfCourseEastandWestLysimeterFullSeasonWaterBalanceValueswithSeasonalCalculatedCropCoefficients ..............................................................................................................................29
Table13:SouthgateGolfCourseEastandWestLysimeterFullSeasonWaterBalanceValueswithSeasonalCalculatedCropCoefficients ..............................................................................................................................30
Table14:SpanishForkTurfPlotNorthandSouthLysimeterFullSeasonWaterBalanceValueswithSeasonalCalculatedCropCoefficients ..............................................................................................................................31
Table15:SunbrookGolfCourseEastandWestLysimeterFullSeasonWaterBalanceValueswithSeasonalCalculatedCropCoefficients ..............................................................................................................................32
TableD1:SeasonalTotalIrrigation,DrainageandTurfWaterUse,1991‐95,2000‐01,fromtwoLysimetersattheLoganGolfandCountryClub,Logan,Utah.PartialSeasonDatafor1996‐99....................................................50
TableD2:TurfgrassWaterUse(ET)andCropCoefficients(Kcm),1991‐95,and2000‐01,fromLysimetersattheLoganGolfandCountryClub,Logan,Utah.PartialSeasonDatafor1996‐99....................................................51
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LISTOFFIGURESFigure1a.PlanViewofinstalledlysimeter(typical).AfterDlamini(2003).................................................................7
Figure2.Excavationoflysimeterplot(Sunbrook,Nov2001).......................................................................................7
Figure1b.Cross‐sectionviewofinstalledlysimeter(typical).AfterDlamini(2003) ..................................................7
Figure3.Plasticperforateddrainpipeinlysimeterbottomandcornerraingagewell(Southgate,Apr2004) ..........7
Figure4.Placementofsodinpartiallyinstalledlysimeter(Southgate,Apr2004) ......................................................8
Figure5.Finishedlysimeterinstallation(Southgate,Dec.2004).................................................................................8
Figure6.Typicalelectronicweatherstationinstallation(Southgatelookingnorthward,05103anemometer) .......10
Figure7a.CumulativelysimeterETandETrforLoganGolfandCountryClub,Logan,Utah,2007 ............................24
Figure7b.CumulativelysimetercropcoefficientforLoganGolfandCountryClub,Logan,Utah,2007....................24
Figure8a.CumulativelysimeterETandETrforMurrayGolfCourse,Murray,Utah,2007 ........................................25
Figure8b.CumulativelysimetercropcoefficientforMurrayGolfCourse,Murray,Utah,2007................................25
Figure9a.CumulativelysimeterETandETrforSouthgateGolfCourse,St.George,Utah,2007 ...............................26
Figure9b.CumulativelysimetercropcoefficientforSouthGateGolfCourse,St.George,Utah,2007.....................26
Figure10.MonthlyKcrvaluesfortheLoganNewLysimeter,2004‐2008 ..................................................................33
Figure11.MonthlyKcvaluesfortheSpanishForkNorthLysimeter,2002‐2006. .....................................................34
Figure12.MonthlyKcvaluesfortheSouthgateEastLysimeter,2004‐2008. ............................................................34
Figure13.MonthlyKcvaluesfortheSouthgateWestLysimeter,2004‐2008. ..........................................................35
Figure14.AverageKcvaluesforeachmonthfortheLoganNewLysimeter..Obviousoutlierswereexcluded.ThedashedlinerepresentsthesuggestedfullseasonKcr. ...........................................................................................35
Figure15.AverageKcvaluesforeachmonthfortheSpanishForkNorthLysimeter.Obviousoutlierswereexcluded.ThedashedlinerepresentsthesuggestedfullseasonKcr. ...................................................................36
Figure16.AverageKcvaluesforeachmonthfortheSouthgateEastLysimeter.Obviousoutlierswereexcluded.ThedashedlinerepresentsthesuggestedfullseasonKcr. ....................................................................................36
Figure17.AverageKcvaluesforeachmonthfortheSouthgateWestLysimeter.Obviousoutlierswereexcluded.ThedashedlinerepresentsthesuggestedfullseasonKcr. ....................................................................................37
Figure18.SuggestedKccurveforthehigherelevationareasofUtah.MonthlyKcvaluesaveragedbetweentheLoganNewandSpanishForkNorthLysimeters.Obviousoutlierswereexcluded. ..............................................37
Figure19.SuggestedKccurveforthelowelevationareasofSouthernUtah.MonthlyKcvaluesaveragedbetweenthetwoSouthgateLysimeters.Obviousoutlierswereexcluded..........................................................................38
Figure20.SuggestedKcocurveforthehigherelevationareasofUtahalongwithKcovaluesforeachmonthaveragedbetweentheLoganNewandSpanishForkNorthLysimeters.AdaptedfromFigure18. .....................39
Figure21.SuggestedKcocurveforthelowelevationareasofsouthernUtahalongwithKcovaluesforeachmonthaveragedbetweenthetwoSouthgateLysimeters.AdaptedfromFigure19. ......................................................40
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ClaytonLewischeckingwaterlevelsattheLoganGolfandCountryClub.
1
VERIFICATIONOFTURFGRASSEVAPOTRANSPIRATIONINUTAH
INTRODUCTION
ThecontinuedcompetitionforwaterinUtahnecessitatesaccurateestimatesofwaterneedsandmanagementrequirementsforlegalwaterallocationaswellashydrologicconsiderations.Competitionforwaterisduetoincreasedurbanandruraldevelopmentaswellasdeclininggroundwaterlevelsandrecurringdroughtconditions.Thishighlightstheimportanceofcarefulwatermanagementincludingurbanwaterconservation,particularlyalongtheWasatchfrontandinhighgrowthareasofUtah.Themajorityofurbanwateruseinthesummerisfromirrigationoflandscapedareas,mostlyturf.Thus,itisimportanttoaccuratelyestimateturfgrasswaterusetosupportwaterconservationefforts.Previousstatewideestimatesofirrigatedcropwateruse(evapotranspiration,orET)inUtahreliedonacombinationofnearstate‐of‐the‐artmethodology(PenmantypeETequation,1982Kimberly,IDversion)atthetimecoupledwithacalibratedBlaney‐Criddleequation(Hill,1994).AcropcoefficientvalueforturfgrassETof0.56wasusedwiththe1982KimberlyModifiedPenmanCombinationalfalfareferenceETequation.Thiscoefficientvaluewasbasedontwoyearsofdata,asof1993,fromlysimetersinstalledintheLoganGolfandCountryClubgolfcourse.ErvinandKoski(1998),reportingaColoradostudy,suggestedthatwatercouldbeconservedbyirrigatingturfeverythreedayswithaKcof0.7(referencealfalfa,ETr,basis)forKentuckybluegrassand0.6forturftypetallfescue.Thesecoefficientvaluesforfescueandbluegrasswereabout7to25%higher,respectively,thantheReport#145value.This,plusotherconcerns,suggestedthatthecoefficientsderivedfromtheLoganGolfandCountryClubsiteinCacheValleymaynotbeapplicablethroughoutUtah.Thus,sitespecificverificationinarangeofconditionswasindicatedtoincreaseconfidenceinturfgrasswateruseestimates.Theoriginallyanticipatedproductofthisresearchwastodetermineverifiedcropcoefficients,Kc,(Wright,1982)forusewiththe1982KimberlyPenmanETrequation(Jensen,BurmanandAllen,1990)alongwithdailyweatherdatatoestimatenearrealtimeturfgrasswateruseinurbanareasofUtah.However,subsequenttotheinitiationofthiswork,theAmericanSocietyofCivilEngineers(ASCE)andtheIrrigationAssociationadopteda“standardized”formofthePenman‐MonteithETrequation(Allen,etal.,2005).ThedesireamongUtah’sstatewateragenciestousethe“standardized”methodprovidedanopportunitytocalibrateitforuseinestimatingturfgrassconsumptiveusethroughoutUtah.
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ObjectivesTheprimarypurposeofthisworkwastoverifyturfgrasscropwaterusecoefficientsforusewitheitheragrassreferenceET(ET0)oranalfalfareference(ETr)equationvalue.Specifically,thetwomainobjectiveswere:A.Studyturfgrasswaterusebymeasurementwithlysimetersincludingcollectionofsufficient
weatherdataateachsiteforusewithaPenmantypecombinationreferenceETequation.B.AnalysisofpreviouslycollectedturfgrassirrigationandsoilwatercontentdataattheBYU
AgronomyFarmnearSpanishFork,Utah.Neutronprobeandotherdatawerecollectedduring1990‐1992(or1993,approximately)fromtheBYUturfplots.However,usableconcurrentweatherdata,soilwatermeasurements,andirrigationdatawerenotobtainedforanytimeperiodforthesestudies.Thus,thisportionofthestudy,asincludedintheoriginalproposal,wasabandoned.
Worktasksbyobjective,ascontainedintheproposal,aregiveninAppendixA.
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EvapotranspirationEstimationEvapotranspirationisarelativelycomplexandnonlinearphenomenon,dependingontheinteractionofairtemperature,solarradiation,wind,vaporpressure(relativehumidity),aswellasonthecroptypeandgrowthstage(leafarea).Evapotranspiration(ET),consumptiveuse,orcropwaterusecanbeestimatedormeasuredbymanydifferenttechniquesdependingonstudyobjectivesandfinancialanddataresources.Thesetechniquesrangefromequationsthatuseonlymonthlyaveragetemperaturestothoroughlyinstrumentedfieldresearchsiteswithweighinglysimeters.Additionaldataoncropwateruseareavailablefromirrigationscheduling,experimentalplots,andfieldresearchstudies.ThegeneralformofthereferenceET‐cropcoefficientapproachtoconsumptiveuseequationsis: ET=KcETr+Ews (1)whereETistheestimatedcropevapotranspiration;KcisanempiricallydeterminedcropcoefficientrelatingcropETtoreferencecropETr;ETriscalculatedETforanalfalfareferencecrop;andEwsisestimatedwetsoilsurfaceevaporationadjustmenttoaccountforconditionsoccurringfollowinganirrigationorsignificantrain.ThisadjustmentismadewhentheKcvalueislessthan1.0,e.g.,intheearlygrowthstagesofarowcroporfollowingacuttingofalfalfa.EwsshouldbeignoredinsituationswheretheKcfactorincludestheeffectofawetsoilsurfaceonE.However,theirrigationscheduleshouldapproximatethatofthesitewheretheKcvaluesweredetermined.ImpliedinEq.1isaKcvaluerepresentingthe“basal”condition(Kcb)sinceEwsisexplicitlyshown.Analternateformofthecropwateruseequationis: ET=KcmETr (2)whereKcmisa"mean"cropcoefficient(Wright,1982)thatincludestheeffectofevaporationfromawetsoilsurfacefromatypicalirrigationscheduleforthegivencrop.Thevalueofacropcoefficient(KcorKcm)ataparticulargrowthstagedependsonplanttranspirationaswellasevaporationfromthesoilsurface.CaremustbeexercisedinapplyingKcmvaluesfromoneresearchsitetoothersiteswithdifferentirrigationpracticesandconditions.Areferencecropofalfalfaisatleast14inches(35cm)tallandadequatelyirrigatedsothattranspirationisnotlimitedbyavailablesoilmoisture.Anothercommonreferenceisthatofclippedgrass(ET0),waternotlimiting.TheavailabilityofreasonablypricedelectronicweatherstationshasallowedroutineuseofPenmantypeequationsforestimatingreferencecropET(ETr).
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ReferenceCropEvapotranspirationTheASCEStandardizedReferenceEvapotranspirationEquationwasusedinordertoobtainwellacceptedreferenceevapotranspiration(ETrs)values.DuetonighttimehighwindconditionsattheLoganGolfandCountryClub,itwasdecidedthatdailysumsofhourlycalculatedETrsshouldbeused.Thiswasbecausethehighwindatnightwhentemperaturesarecool,andturfgrassstomataareclosed,resultsinahighcalculationofETrifcalculationsaremadeusing24hourdataonly.AprogramwaswritteninVisualBasicforcalculatingdailyASCEstandardizedETrsbysumminghourlyETrvalues.Manyreferenceevapotranspirationequationshavebeenusedhistorically.Asmentionedpreviously,theAmericanSocietyofCivilEngineers(ASCE)andtheIrrigationAssociationadopteda“standardized”formofthePenman‐MonteithETrequationin2005(Allen,etal.,2005).ThisequationisnowagenerallyacceptedmethodofcalculatingETr.TheASCEstandardizedPenman‐MonteithequationoverestimatesETrinthespringandfallatKimberly,Idaho(Wrightetal.,2000),wherethe1982KimberlymodifiedPenmancombinationequationwascalibrated,thusnecessitatingtheuseof“corrected”cropcoefficients(AllenandWright,2002).TheASCEStandardizedPenman‐MonteithETrsequationcanbeusedforbotha“tall”(alfalfa)or“short”(grass)referencecropcalculationmode:
(3)
whereETrsisthestandardizedreferenceevapotranspiration(mm/dormm/hr)fora“tall”crop(denotedbythesubscript“rs”),Δistheslopeofthesaturationvaporpressure–temperaturecurve(kPa/°C),Rnisthecalculatednetradiationatthecropsurface(MJ/m2/dorMJ/m2/hr),G issoilheatflux(MJ/m2/dorMJ/m2/hr),γisthepsychrometricconstant(kPa/°C),Cnisthenumeratorconstant(changeswithtimestepandreferencecroptype)(Kmms3/Mg/dorKmms3/Mg/hr),Tismeantemperatureforthecalculationinterval(dailyorhourly)(°C),u2ismeanwindspeedforthecalculationintervalataheightof2mabovetheground(m/s),esisthesaturationvaporpressureat2mabovetheground(kPa),eaisthemeanactualvaporpressureat2mabovetheground(kPa),Cdisthedenominatorconstant(changeswithtimestepandreferencetype(s/m).Theunitsforthecoefficient0.408arem2mm/MJ.Forthisstudya“tall”crop(alfalfa)wasusedasthereferencetypeandthecalculationswereperformedonanhourlybasis.W
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WaterBalanceEstimatesofEvapotranspirationWhenappliedtoanirrigatedplot,themassbalanceequationcanberepresentedas: P+I+Ri+Up=ET+DP+Ro+ΔS (4)wherePisprecipitation,Iisirrigation,Riissurfaceflowontothefield,Upiscapillarityorupwardflow,DPisdeeppercolation,RoisrunoffandΔSischangeinsoilmoisture(SW1–SW2).TheuseoflysimeterseliminatestheturfgrassRi,Up,andRotermsinEq.4.Thus,sinceP,I,DPandΔScanbemeasured,theETtermcanbeestimatedastheresidual.
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PROCEDURES
LysimeterTechniquesforMeasuringTurfgrassWaterUseAlysimeterisatankfilledwithsoilthatcontainsthesamevegetationastheadjacentarea.Alysimeterisolatesthesoilmassandvegetationsowatercannotenterorleave,thusmakingitpossibletoaccuratelymonitorwaterrequiredtomaintainplantgrowthtodetermineevapotranspiration(ET)orconsumptiveuse.ETisoftendeterminedwithlysimetersthatweighchangesinthesoilmoisture.Thescopeofthisstudyandcostofweighinglysimetersmadenon‐weighing,drainagetypelysimetersareasonablealternative.Thistypeofnon‐weighinglysimeterwasusedinafieldestimationofwetmeadowETintheUpperBearRiverofIdaho,UtahandWyoming(Hill,etal.,1989);inastudyofhydrophyte(bulrushandcattail)wateruseinCacheValley,Utah(Allen,PruegerandHill,1992)andinastudyofETfromformerlyirrigatedlandsintheSouthParkareaofColorado(Quinlan,BurmanandSiemer,1982).Twolysimeterswerepreviously(fallof1991)installedintheLoganGolfandCountryClubandcontinuedinusethroughthisstudy.Lysimetersspecificallyforthisstudywerefabricatedinearlyfall2001andinstalled,twoateachsite,beginninginNovember2001atSt.George(SunbrookGolfCourse)andMurrayParkwayGolfCourseandinspring2002attheBYUSpanishForkFarm.Subsequently,twomorelysimeterswereinstalledatSouthgateGolfCourse(2004,St.George)andonemoreatLoganmakingthreeatLoganandeleventotalatthefivesites.
Construction
Thelysimeterswereconstructedfrom10gaugesteelplates,whichwerecutandbent.Thejointswerearc‐weldedandthelysimeterswerethenpowdercoated(white).Thelysimetersare11.1squarefeet(40inchesx40inches)and18,24,or30inchesdeep,dependingonsiteandfabricationdate,withadrainagepipeoutletinacorner.Aperforated3or4inchdiameterplasticdrainagepipewasplaceddiagonallyacrossthebottom.Typicalinstallationplanandcross‐sectionviewsofinstalledlysimetersareshowninFigure1.
InstallationMethods
Lysimeterswereinstalledinrepresentativeareasofirrigatedturf.Thesodmatwasremovedwithashovelandremainingmaterialwasremovedandplacedonsheetsofplywoodintheorderofremoval(Fig.2).Alysimeterwasplacedintheexcavatedholeandleveled.Alipofapproximately½to2inchesprotrudedabovethegroundtopreventsurfacewaterfromenteringthelysimeter.TheplasticdrainagepipewasplacedinthelysimeterasshowninFigure3.Thedrainagepipewascoveredbyabout2inchesofsandandthesoilremovedinexcavatingtheholewasreplacedin8to10inchliftsandcompacted.Intactsodpiecesremovedduringexcavationwerereplaced(Fig4)insimilarpatternasinajig‐sawpuzzle.Similarinstallationwas
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realizedateachlocationandthevegetationinthelysimeterswasrepresentativeofthatinthesurroundingarea(Fig5).
FIGURE1A.PLANVIEWOFINSTALLEDLYSIMETER
(TYPICAL).AFTERDLAMINI(2003)
FIGURE2.EXCAVATIONOFLYSIMETERPLOT
(SUNBROOK,NOV2001)
FIGURE1B.CROSS‐SECTIONVIEWOFINSTALLEDLYSIMETER(TYPICAL).AFTERDLAMINI(2003)
FIGURE3.PLASTICPERFORATEDDRAINPIPEINLYSIMETERBOTTOMANDCORNERRAINGAGEWELL
(SOUTHGATE,APR2004)
8
FIGURE4.PLACEMENTOFSODINPARTIALLY
INSTALLEDLYSIMETER(SOUTHGATE,APR2004)
FIGURE5.FINISHEDLYSIMETERINSTALLATION
(SOUTHGATE,DEC.2004)A15‐inchdiameterPVCpipewasplacedverticallyinaholeadjacenttothedrainpipeoutlet.Thiswascoveredwithasteellid(Fig4)andservedasamanholeforthe5gallon(atLogan)or6gallondrainagebuckets.Four‐inchdiameterraingageswereplacedin6‐inchdiameterPVCpipessunkintothegroundoutsidetwooppositecornersofthelysimeters(Fig3).Thetopsoftheraingageswereapproximatelyflushwiththesurface.InstallationdatesandlysimeterdeptharegiveninTable1.Thevegetationinthelysimeterswasmanagedthesameastheadjacentturf.Wheninstallationwasinthespring,measurementsbeganimmediately,eventhoughtheturfmaynothavebeenfullyestablished.
TABLE1:INSTALLATIONDATESANDDEPTHOFLYSIMETERS Lysimeter
Location InstallationDate Depth(in)LoganGolfandCountryClubEast&West September17,1990 18
New April7,2004 24MurrayGolfCourse November16,2001 30SouthGateGolfCourse April8,2004 24SpanishFork April9,2002 30SunbrookGolfCourse November15,2001 30
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FIELDPROCEDURES(DATACOLLECTION)
Alllysimetersiteswerevisitedweeklyduringtheearlyandlategrowingseason,usuallymid‐AprilandthroughOctober.Whereastwiceweeklyvisitsweremadeinthemid‐growingseasonwheredrainageamountscouldhavecausedovertoppingofthebucketsatlongerobservationintervals.TwiceweeklyvisitsweregenerallymadeatLogan,SpanishForkandSouthgate.Ateachvisitmeasurementsweremadeofwaterinthetworaingagesandthevolumeordepthofwaterinthedrainagebucket.Ifnecessary,grasswasclippedfromaroundtheraingages.AprotocolforthelysimeterobservationsisinAppendixB.Thedrainage(ifany)wasmeasuredwitha1000mlgraduatedcylinder;largerdrainageamountsweremeasuredastwodepthreadingsinthedrainagebucket,takenatoppositesidesofthebucket.Aftereachreadingraingagesanddrainagebucketswereemptied.Occasionallyadditionalwaterwasaddedtosomeofthelysimetersinordertoinducedrainage.Thiswastypicallydoneonlysimeterswhichhadnotproduceddrainageforanextendedperiodoftime.Consumptiveuse,evapotranspiration,ofthelysimetervegetationwascalculatedusingasimplewaterbalanceequation: CU=ETlys=∆SW+(Irrigation+Rain)+Wadded–Drain (5)
whereCUisconsumptiveuse,equivalenttoevapotranspiration,ETlys;∆SWischangeinsoilwater;(Irrigation+Rain)isthecontentofaraingage(whichcouldbebothirrigationand/orrain);Waddedisextrawateraddedtothelysimeter(bydumpingbucketsofwaterasdescribedabove)andDrainisdrainagewaterinthebucket.Thechangeinsoilwater,∆SW,wasassumedtobenegligibleaslongasdrainageoccurredregularly.However,duringsomeseasonsandparticularlyatMurray,drainagedidnotoccurforseveralweeksatatime.WEATHERDATACOLLECTIONAutomatedelectronicweatherstations(EWS)wereequippedtomonitorairtemperature,soiltemperature,relativehumidity,solarradiation,windspeed,winddirection(exceptatLogan)andprecipitation.Thesensorsweresampledevery10secondsandhourlyanddailymaximums,minimums,averages,andtotalswerecalculatedandsavedinon‐boardmemory.EachstationwasoutfittedwithaCampbellScientific,Inc.(CSI)CR10Xmicrologger(CR10atSpanishFork).ThesensorsanddataloggerweremountedonCSItripodinstrumentplatforms(Figure6).SpecificinstrumentationcomponentpackagesforeachstationarelistedinAppendixC.
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FIGURE6.TYPICALELECTRONICWEATHERSTATIONINSTALLATION(SOUTHGATELOOKINGNORTHWARD,05103ANEMOMETER)Weatherstationlocations(coordinates)aregiveninTable2alongwithsiteelevationandeachstation’sanemometertypeandheightabovethegroundsurface.Elevationsvaryfrom2,572(Southgate)to4,790(Logan)ftabvmsl.The014A(MetOne)anemometerisacuptypedevicewhereasthe05103(R.MYoung)isapropellertype.SensorheightsaregreateratLoganandMurrayinanattempttoelevatethesensorsabovesprinklerstreamheights.Weatherdataforallthesites(exceptSunbrook)arepresentlyavailableonthewebatURL:http://extension.usu.edu/agweather.TABLE2:COORDINATESANDELEVATIONSOFELECTRONICWEATHERSTATIONSATTURFLYSIMETERSITESINUTAH
Site Latitude LongitudeElevation
(ft)Elevation(m)
AnemometerTypeHeight(m)
LoganGolfandCountryClub N41°44.682' W111°47.363' 4790 1460 014A 4N40°37.881' W111°55.190' 4294 1309 014A 4MurrayGolfCourse
SouthGateGolfCourse N37°04.434' W113°35.414' 2572 784 05103 3N40°04.031' W111°37.753' 4680 1427 014A 3SpanishFork
SunbrookGolfCourse N37°06.488' W113°38.044' 2678 816 05103 3
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SITEDESCRIPTIONSCacheValley–LoganGolfandCountryClubThegolfcourseissituatedinthemouthofLoganCanyon,ontheeastsideofCacheValleyinNorthernUtah,about2.5milesENEalongHighway89fromthe400NorthandMainStreetintersectioninLoganatanelevationofabout4790feet.Thecourseitselfisonanoldlaketerrace,depositedunderancientLakeBonneville.ThesoilisclassifiedasaRicksgravellyloamwithparentmaterialofalluviumanddeltaicsedimentsderivedfromlimestone,sandstoneandquartzite.Thelysimetersitehas6‐12inchesofloamtopsoilunderlaidbygravellyloam(includesriver‐rungraveluptocobblesize,Fig7).Wintertemperaturesdropaslowas20degreesbelowzeroFahrenheit,whereassummerhightemperaturesmayreach90degreesFahrenheitandabove.Thefrostfreeperiodis140to160days.Normal(1971‐2000)annualprecipitationis19.9inches.ThelysimetersaresituatedontheSEsideofthecourseclosetotheLoganCanyonmouth,westofthegreensnurseryandnorthofthefairwayforthe3rdhole.TheturfisaMerionbluegrass.Thecuttingheightissetat1½inchesintherough,wherethelysimetersarelocated,andat3/4ofaninchinthefairways.Theirrigationseasonisgenerallyfrommid‐MayintolateSeptemberorearlyOctober.Irrigationisin12‐minutecyclesupto2timesperday,ifneeded.Sprinklersareplacedina65ft.triangularspacingwithnozzledischargeof20.5gpm.Thefirstseasonoflysimeterdatacollectionbeganinthespringof1992(EastandWest)andMay2004(New)andhascontinuedtothepresent.Datacollectionwasinitiatedinthespringaftersnowmeltandcontinuedonintolatefallorearlywinter,untilsignificantsnowcover.Theperiodofmeasurementofturfgrasswaterusevariedfromyeartoyear,asaffectedbytheoccurrenceofsnowinthespringandthefall,butwasgenerallyfrommid‐ApriltolateOctober.Weatherdatafromtheweatherstationwasretrievedonceperweek,priortowhenthewebsitefiletransferprotocol(FTP)processwasestablished.SaltLakeCounty–MurrayParkwayGolfCourseThegolfcourseislocatedinmidSaltLakeValley,about0.5mileseastoftheJordanRiver,southofI‐215andnorthofWinchesterBlvd(66thSouth)inMurray.ThelocalareasoilisclassifiedasaKidmanveryfinesandyloamwithparentmaterialoflacustrinedeposits.Thelysimetersiteisonimported(hauledin)soilmaterial.Thereare6‐10inchesofloamtopsoilunderlainbyclayeygravel(uptocobblesize,Fig8).Itisnearthevalleybottomatanelevationofabout4285feet.Wintertemperaturesdropaslowas5degreesbelowzeroFahrenheit,whereassummerhightemperaturesmayreach95degreesFahrenheitandabove.Thefrostfreeperiodis160to180days.Normal(1971‐2000)annualprecipitationis16inches.Thelysimetersaresituatedonthesouthsideofthecourse,northofthefairwayforthe16thhole,about70feeteastofthe150yardmarker,390feetNWofthemaintenanceshedand200feetnorthoftheweatherstation.TheturfisaKentuckybluegrassandperennialryegrass
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mixture.Thecuttingheightissetat2inchesintherough,wherethelysimetersarelocated,andat3/4ofaninchinthefairways.TheirrigationseasonisgenerallyfromearlyMayintoearlyOctober.Irrigationisin9‐minutecyclesupto3timesperday,ifneeded.Sprinklersareplacedina70ft.triangularspacingwithnozzledischargeof22.5gpm.Thefirstseasonoflysimeterdatacollectionbeganinthespringof2002andhascontinuedtothepresent.Datacollectionwasinitiatedinthespringaftersnowmeltandcontinuedonintolatefallorearlywinter,untilsignificantsnowcover.Theperiodofmeasurementofturfgrasswaterusevariedfromyeartoyear,asaffectedbytheoccurrenceofsnowinthespringandthefall,butwasgenerallyfromearlyApriltolateOctober.DatafromtheweatherstationwasobtainedfromoccasionalsitevisitsaswellasfromthewebsiteFTPprocess.UtahCounty–BYUSpanishForkFarmTheBYUAgronomyturfplotsareabout3¼milesSSEofSpanishForkandabout¾mileSEoftheBYUDairy(nolongerinexistence).Theplotsareonanoldlaketerrace,depositedunderancientLakeBonneville.ThesoilisclassifiedasaTimpanogosloamwithparentmaterialoflacustrinedepositsderivedfromlimestone,quartziteandgranite.Thelysimetersitehasabout24inchesofloamtopsoilunderlainbysiltloam(Fig9).ItislocatednearthemouthofSpanishForkCanyonatanelevationofabout4700feet.Wintertemperaturesdropaslowas10degreesbelowzeroFahrenheit,whereassummerhightemperaturesmayreach95degreesFahrenheitandabove.Thefrostfreeperiodis150to170days.Normal(1971‐2000)annualprecipitationis21.6inches.Thelysimetersaresituatedabout240yardsSSWofthefieldshed,180yardsSWoftheweatherstationandabout15feeteastofaline‐sourcesprinklerusedtoapplyvaryingamountsofwatertotheturfplots.Theturfintheplotssurroundingthelysimetersisafescue.However,thelysimeterswerere‐soddedwithbluegrass.Cuttingheightwasabout2inchesandthelysimeterswerehandclippedtomatch.Theirrigationseasonwasgenerallyfrommid‐MayintoearlyOctober.Irrigationwasscheduledaboutonceperweekwiththedurationadjustedasneededtoprovidetheappropriatedepthofwateratthelysimeters.Sprinklerswereplacedabout20ft.apartalongthelinewithnozzledischargeof8‐9gpm.Thefirstseasonoflysimeterdatacollectionbeganinthespringof2002andcontinuedthrough2006whenfarmmanagementchanged.Datacollectionwasinitiatedinthespringaftersnowmeltandcontinuedonintolatefallorearlywinter,untilsignificantsnowcover.Theperiodofmeasuringturfgrasswaterusevariedfromyeartoyear,asaffectedbytheoccurrenceofsnowinthespringandthefallbutwasgenerallyfromearlyApriltolateOctober.Weatherdatafromtheweatherstationwasobtainedfromoccasionalsitevisitsaswellasfromthewebsite.WashingtonCounty–SouthgateGolfCourseThegolfcourseis2milesSSWofSt.Georgeabout0.3mileswestoftheI‐15crossingovertheSantaClaraRiver.ItislocatedalongtheSantaClaraRiveratanelevationofabout2550feet.
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ThesoilisclassifiedasaToblerfinesandyloamwithparentmaterialofalluviumderivedfromsandstoneandshale.Thereddishcoloredsandysoilismorethan3feetdeep(Figs3and4).Wintertimetemperaturesaremoderatealthoughminimumsdropbelowfreezing,whereassummertimehightemperaturesmayreach110degreesFahrenheitandabove.Thefrostfreeperiodis210to240days.Normal(1971‐2000)annualprecipitationis8.8inches.Thelysimetersaresituatedaboutinthemiddleofthecourse,about100yardseasterlyoftheclubhouse,about200ftfromthe1stteeandabout35to50feetsouthandeastoftheweatherstation(Fig10).TheBermudagrassturfisoverseededbyperennialryegrassintheearlyfall(September).Thecuttingheightissetat1½inchesintheroughnorthofthefairway,wherethelysimetersarelocated.Irrigationoccursallyearwiththefrequencyvaryingfromdailyinthesummertoonceeveryweekorlessfrequentinthewinter,dependingontheoccurrenceofwinterrains.TheirrigationdurationisadjustedtomatchETvaluesandspecificlocationsoilconditionsacrossthecourse.Sprinklersareplacedina70ft.triangularspacingwithnozzledischargeof32gpm.ThefirstseasonoflysimeterdatacollectionbeganinJuneof2004andcontinuedintomid‐December2008.Datacollectioncontinuedgenerallyyeararound.Theperiodofmeasurementofturf‐grasswaterusevariedsomewhatfromyeartoyear,asaffectedbypersonnelavailability.Theweatherdatafromtheweatherstationwasobtainedfromoccasionalsitevisitsaswellasfromthewebsite.WashingtonCounty–SunbrookGolfCourseThegolfcourseisabout3¼milesWNWofSt.Georgeandabout2milesSSWofSantaClara.ItislocatedalongtheSantaClaraRiveratanelevationofabout2670to2720feet.ThesoilisclassifiedasaToblerfinesandyloamwithparentmaterialofalluviumderivedfromsandstoneandshale.Thelysimetersitesandyloamsoilisuniformandmorethan3feetdeep(Fig2).Wintertemperaturesaremoderatealthoughminimumsdropbelowfreezing,whereassummerhightemperaturesmayreach110degreesFahrenheitandabove.Thefrostfreeperiodis210to240days.Normal(1971‐2000)annualprecipitationis8.8inches.Thelysimetersaresituatedinthenorthendofthedrivingrange,whichisaboutinthemiddleofthecourse,270yardsnorthoftheclubhouse,130feetsouthofthemaintenanceshedandaboutto230feetnortheastoftheweatherstation(Fig11).TheKentuckybluegrass/perennialryegrass/Bermudagrassturfisoverseededbyannualryegrassintheearlyfall(September).Duetoherbicideeffects,thelysimetersandadjacentareawerere‐soddedtoturftypefescuemid‐June2004.Thecuttingheightissetat1½incheswherethelysimetersarelocated.Irrigationoccursduringthenightandisyearround.Irrigationfrequencyvariesfromdailyinthesummertoonceeveryweekorlessfrequentlyinthewinter,dependingontheoccurrenceofwinterrains.TheirrigationdurationisadjustedtomatchETvaluesandspecificlocationsoilconditionsacrossthecourse.Sprinklersareplacedina65foottriangularspacingwithnozzledischargeof30to35gpm.
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Thefirstseasonoflysimeterdatacollectionbeganin2002andcontinuedthrough2006.Datacollectioncontinuedgenerallyyearround.Theperiodandconsistencyofmeasuringturfgrasswaterusevariedsomewhatfromyeartoyear,asaffectedbypersonnelavailability.Theweatherdatafromtheweatherstationwasobtainedfromoccasionalsitevisitsaswellasfromthewebsite.
DataAnalysis
WeatherData
Thecollectedweatherdatawasanalyzedandreviewedtoremoveerrorsandinaccurateormissingvalues.ThesolarradiationsensorcalibrationwascorrectedforeachseasonbycomparingobserveddailytotalsolarradiationwiththeoreticalcleardaysolarradiationusingtheproceduredescribedinHill(1994)andAllen,etal.(2005).Themostfrequentcorrectionsinvolvedmissinghourlydata.Onsuchoccasions,valuesforthemissinghourwereestimatedbyaveragingthevaluesfromthehoursbeforeandafterthemissingone.DetailsofthecorrectionsoradjustmentsmadetotheweatherdatabysiteandyeararegiveninAppendixE.
LysimeterData
Actualevapotranspiration(ETa)wascalculatedbyperformingasimplewaterbalanceforeachlysimeter.Asummationwasdonefortotalrainplusirrigationmeasuredinthetworaingagesneareachlysimeterandanaverageofthetwovalueswastakentorepresenttherainplusirrigationwhichwasappliedoverthelysimeterarea.Thisvaluewasaddedtothesumofadditionalwaterappliedtothelysimeter(whichwasconvertedintoanequivalentdepthoverthelysimeter).ThesumoftheequivalentdrainagewassubtractedfromthisvaluetoobtaintotalETforthecalculationperiod(seeEquation5).AnentirecalculationperiodETlyswasdeterminedby: ∑ETlys=∑(R+I)+∑Wadded‐∑D (6)where ETlysislysimeterestimatedevapotranspiration(in),Risrain(in),Iisirrigation(in),Waddediswateradded(in)andDisdrainage(in). Themeasuredbucketdrainagedepthwasconvertedintoanequivalentdepth,by:
(7)
whereDistheequivalentdepthofdrainageoverthelysimeter(in),havgistheaverageheightofwaterinthedrainagebucket(in),Alysistheareaofthelysimeter(1600sqin),Dtopisdiameter
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ofthetopofthebucket(in),Dbottomisdiameterofthebottomofthebucket(in)andhbucketisheightofthebucket(in).DailySoilWaterBalanceModel
Onanumberofoccasionsfornearlyallofthesitesthedrainagebucketswereobservedtohaveovertoppedbetweenvisits.Suchaneventcausesalossofdatabecausetheexactvolumeofdrainageisnotknown.InordertoobtainareasonableestimationoftheactualdrainageontheseoccasionsamodelwasdevelopedinVisualBasic.Themodelperformedrunningsoilwaterbalanceforeachdayduringthecalculationperiodfromwhichitcalculateddailydeeppercolation(DP)(seeEquation6).Thefirstreadingwasignoredbytheprogramsincethetotalprecipitationwhichresultedintheinitialdrainagereadingwasnotknown.Thedailysoilwaterbalancemodelisrepresentedby: DPi=(SW1)i‐(SW2)i+(R+I)i+(Wadded)i–Kc(ETrs)i (8)whereDPiisdeeppercolation(in),(SW1)Iistheinitialsoilwatercontentforthecurrentday(in),notethat(SW1)i=(SW2)i‐1(SW2)Iisthefinalsoilwatercontentforthecurrentday(in),(R+I)iistherainplusirrigationobservedforcurrenttheday(in),(Wadded)Iisthewateraddedtothelysimeteronthecurrentday(in),Kcisthecropcoefficientdeterminedbytheuser(decimal)and(ETrs)IistheASCEstandardizedreferenceevapotranspiration(in).InputforthemodelwasacommadelineatedfilecontainingthesumofthehourlycalculatedETrsforeachdayaswellasthelysimeterreadingsforeachobservation.Areasonablefullseasoncropcoefficientwasinputintothemodelaswellasanavailablewatercontentofthesoilinthelysimeter(AW)andtheinitialsoilwatercontentasestimatedforthecalculationperiod(SW0).TheSW0wasassumedtobeequaltotheAWfornearlyallofthelysimeterseachyear.Thisassumptionwasjustifiedbecausetypicallyacalculationperiodbeganearlyintheyearanddrainagewasoftenobservedonthefirstobservation,meaningthatthesoilwatercontentwasatfieldcapacityatthattime.Valuesofsoilparameters,AWandSW0usedforthecalculationsperformedbythesoilwaterbalancemodelaregiveninTable3.TheSW0valueatMurrayfor2003wasassumedtobehalfoftheAW,becausenoorlittledrainagewasobservedateitherlysimeterfortheentireseason(0inchesattheEastand0.03inchesattheWest).Thiswasneededinordertoobtainreasonableresultsfromthemodel.
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TABLE3:AVAILABLEWATERCONTENTANDINITIALSOILWATERCONTENTS
USEDINTHESOILWATERBALANCEMODEL AW SW0Location (in) (in)LoganGolfandCountryClubEast&West 2.6 2.6
New 3.2 3.2MurrayGolfCourse* 4.6 4.6SouthGateGolfCourse 2.4 2.4SpanishFork 4.6 4.6SunbrookGolfCourse 3.0 3.0
*TheSW0forbothlysimetersatMurrayGCin2003wassetto2.3in.Themodelcouldbeusedtocalculatethemeancropcoefficientfortheseasoniftherewerenoproblemswithovertoppeddrainagebuckets,oriftheseeventshadbeenadjustedfrompreviousrunsofthemodel.TheKcvaluecouldbedeterminediftheinputKcvaluewereadjusteduntilthecalculateddeeppercolationwasequaltothemeasured,oradjusted,drainage.ThisprovidedKcvalueswhichcouldbeusedtoverifythevaluesobtainedbythemethoddescribedinEquations5and6.Themodelestimatesdrainagebasedonasoilwaterbalance,forthosedayswhenadrainagebucketspilledovertop(andthuslostdata).Thisestimateddrainagevaluewastheninsertedintothedatafileandthemodelwasrunagain.TheKcvalueswereobtainedusingtheadjusteddrainagevalues.AdescriptionoftheadjustmentsisgiveninAppendixF.
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RESULTSANDDISCUSSIONOBSERVATIONANDCALCULATIONPERIODSTheperiodforwhichconsumptiveusecalculationswereperformedeachyearvariedfromlocationtolocationandwerenotalwayscontinuousthroughoutthegrowingseason.ThebeginningandendingdatesofweatherandlysimeterdatacollectionandthecalculationperiodsforLogan,Murray,SpanishFork,SouthgateandSunbrook,aregiveninTables4through8,respectively.Fullcalendaryearweatherdatawasavailablefornearlyeverylocationandyearofthestudywiththefollowingexceptions:January1throughMarch31,2006wasomittedatMurrayduetoerrorsinthedata,SouthgatedatabeganonJune23,2004andSunbrookdatabeganonFebruary22,2002(Tables5,6,and8).ThecalculationperiodandobservationperiodforlysimeterdataattheLogangolfcoursearethesameeveryyearexcept2004and2006(Table4).ThenewlysimeteratLoganwasinstalledonApril7,2004.ForthispurposethecalculationperiodforthatyearbeganonMay7.ThecalculationperiodbeganonApril26,2006duetosomeinconsistenciesinthedatacollectedonApril19fortheWestlysimeter;thereforethefirsttworeadingswereneglected.
TABLE4:LOGANGOLFANDCOUNTRYCLUBBEGINNINGANDENDINGDATESFORDATACOLLECTIONANDCALCULATIONPERIODS
Weather Lysimeter CalculationPeriodBeginDay EndDay BeginDay EndDay BeginDay EndDayYear
Date Day Date Day Date Day Date Day Date Day Date Day2002 1‐Jan 1 31‐Dec 365 25‐Mar 84 14‐Oct 287 25‐Mar 84 14‐Oct 2872003 1‐Jan 1 31‐Dec 365 17‐Mar 76 13‐Oct 286 17‐Mar 76 13‐Oct 2862004* 1‐Jan 1 31‐Dec 366 27‐Mar 87 18‐Oct 292 7‐May 127 18‐Oct 2922005 1‐Jan 1 31‐Dec 365 15‐Mar 74 24‐Nov 328 15‐Mar 74 24‐Nov 3282006 1‐Jan 1 31‐Dec 365 14‐Apr 104 8‐Nov 312 26‐Apr 116 8‐Nov 3122007 1‐Jan 1 31‐Dec 365 5‐Apr 95 17‐Nov 321 5‐Apr 95 17‐Nov 321*ThenewlysimeterwasinstalledonApril7,2004.ThisisthereasonthecalculationperiodbeganonMay7.
TheonlyyearatMurraywhichhadacalculationperioddifferingfromthelysimeterdataperiodofrecordwas2005(Table5).ThiswasbecauseofanabnormallylargeprecipitationeventonApril4.Thiseventcausedskewedresultsandthusthedatawasnotincludedforthepreviousweeksorthefollowingtwoweeksinordertoinsureamoretypicalsituation.
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TABLE5:MURRAYPARKWAYGOLFCOURSEBEGINNINGANDENDINGDATESFORDATACOLLECTIONANDCALCULATIONPERIODS
Weather Lysimeter CalculationPeriodBeginDay EndDay BeginDay EndDay BeginDay EndDayYearDate Day Date Day Date Day Date Day Date Day Date Day
2002 1‐Jan 1 31‐Dec 365 4‐May 124 14‐Oct 287 4‐May 124 14‐Oct 2872003 1‐Jan 1 31‐Dec 365 15‐Apr 105 13‐Oct 286 15‐Apr 105 13‐Oct 2862004 1‐Jan 1 31‐Dec 366 29‐Mar 89 15‐Nov 320 29‐May 89 15‐Nov 3202005 1‐Jan 1 31‐Dec 365 7‐Mar 66 26‐Sep 269 25‐Apr 115 19‐Sep 2622006 1‐Apr 91 31‐Dec 365 20‐Mar 79 25‐Sep 268 20‐Mar 79 25‐Sep 2682007 1‐Jan 1 31‐Dec 365 2‐Apr 92 19‐Nov 323 2‐Apr 92 19‐Nov 323
ThecalculationperiodforSouthgateGolfCoursebeganonJune11,2004(Table6),whichwasaboutaweekafterinstallation.However,theweatherstationwasnotinstalleduntilJune22.TheweatherdataforJune11throughJune22wasobtainedfromthestationatSunbrookGolfCourse.Thiswasjustifiedbecauseoftheproximityofthetwoweatherstations(approximately3.4milesapart)andtheobservationthatdatafromthetwolocationswasquitesimilar.In2006therewasabreakindatacollectionduetochangesinpersonnelatbothSouthgateandSunbrook;thisisthereasonforthelatebeginningdateforthecalculationperiod.
TABLE6:SOUTHGATEGOLFCOURSEBEGINNINGANDENDINGDATESFORDATACOLLECTIONANDCALCULATIONPERIODSWeather Lysimeter CalculationPeriod
BeginDay EndDay BeginDay EndDay BeginDay EndDayYear
Date Day Date Day Date Day Date Day Date Day Date Day2004 23‐Jun 174 31‐Dec 366 9‐Apr 100 4‐Dec 339 11‐Jun 162 4‐Dec 3392005 1‐Jan 1 31‐Dec 365 10‐Mar 69 2‐Dec 336 10‐Mar 69 2‐Dec 3362006 1‐Jan 1 31‐Dec 365 23‐Jan 23 1‐Dec 335 23‐Jun 23 1‐Dec 3352007 1‐Jan 1 31‐Dec 365 24‐Jan 24 29‐Dec 363 24‐Jan 24 29‐Dec 363
TheonlyyearsatSpanishForkwithcalculationperiodsshorterthantheperiodofrecordforthelysimeters,were2002and2003(Table7).In2002waterwasaddedtobothlysimetersonMay20.Thelysimetershadbeeninstalledthepreviousmonthandhadmostlikelynotcompletelysettled.TheresultsseemedmuchmoreappropriatewhentheweekseffectedbythewateradditiononMay20wereeliminated.In2003therewasalatespringsnowfalleventonApril8,whichcausesinaccurateprecipitationreadings.Thus,thebeginningdateforthecalculationswaschangedtoApril30.
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TABLE7:SPANISHFORKBEGINNINGANDENDINGDATESFORDATACOLLECTIONANDCALCULATIONPERIODSWeather Lysimeter CalculationPeriod
BeginDay EndDay BeginDay EndDay BeginDay EndDayYearDate Day Date Day Date Day Date Day Date Day Date Day
2002 1‐Jan 1 31‐Dec 365 10‐May 130 3‐Oct 276 5‐Jun 156 3‐Oct 2762003 1‐Jan 1 31‐Dec 365 17‐Mar 76 10‐Nov 314 30‐Apr 120 10‐Nov 3142004 1‐Jan 1 31‐Dec 366 1‐Apr 92 10‐Nov 315 1‐Apr 92 10‐Nov 3152005 1‐Jan 1 31‐Dec 365 22‐Mar 81 2‐Nov 306 22‐Mar 81 2‐Nov 3062006 1‐Jan 1 31‐Dec 365 24‐Apr 114 11‐Oct 284 24‐Apr 114 11‐Oct 284
AnumberofdatacollectionproblemsoccurredatSunbrookGolfCourse.Theonlyyearsforwhichthecalculationperiodmatchedthelysimeterperiodofrecordwere2004and2005(Table8).In2002theweatherstationwasnotinstalleduntilFebruary22,sothecalculationperiodbeganatthenextlysimeterobservation(February25).DatacollectionwassporadicduringJanuary2003,thereforethecalculationperiodbeginsonFebruary3.In2006therewasalargegapinthelysimeterdatabetweenMarch29andJune26,sodataprevioustothisgapwasexcludedfromthestudy.
WEATHERDATAADJUSTMENTSANDCALCULATEDREFERENCEEVAPOTRANSPIRATIONSolarradiationsensorcalibrationcorrectionfactorsforeachsiteandyeararegiveninTable9.Acorrectionfactorlessthanoneindicatesthatrecordedsolarradiationsensorvaluesarehigherthanwhatwouldhavebeenobtainedfromafieldsensorwiththecorrectcalibrationprogrammedintothedatalogger.Correctionfactorsvariedfrom0.969(Murray,2007)to1.087(SpanishFork,2004).Thisindicatesthatfieldsensorvaluesvariedfromabout3%highto9%low.ThesensorsatLoganandMurraygenerallyrequiredlesseradjustmentsafterthefactthansensorsatothersites.Thecalculationtimesteps,hourlyordaily,thatwerepossibleateachsitearealsogiveninTable9.Generally,datafromtheyear2002werestoredonlyat2hourintervals,thushourlycalculationswerenotfeasible.Beginningwith2003,alldataloggers,exceptatSpanishFork,wereprogrammedforhourlydatastorage,whichfacilitatedhourlyaswellasdailytimestepcalculations.
TABLE8:SUNBROOKGOLFCOURSEBEGINNINGANDENDINGDATESFORDATACOLLECTIONANDCALCULATIONPERIODS
Weather Lysimeter CalculationPeriodBeginDay EndDay BeginDay EndDay BeginDay EndDayYearDate Day Date Day Date Day Date Day Date Day Date Day
2002 22‐Feb 53 31‐Dec 365 7‐Jan 7 5‐Nov 309 25‐Feb 56 5‐Nov 3092003 1‐Jan 1 31‐Dec 365 2‐Jan 2 10‐Nov 314 3‐Feb 34 10‐Nov 3142004 1‐Jan 1 31‐Dec 366 1‐Mar 61 21‐Sep 265 1‐Mar 61 21‐Sep 2652005 1‐Jan 1 31‐Dec 365 18‐Jan 18 28‐Dec 362 18‐Jan 18 28‐Dec 3622006 1‐Jan 1 31‐Dec 365 5‐Jan 5 16‐Oct 289 26‐Jun 177 16‐Oct 289
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TABLE9:SOLARRADIATIONCALIBRATIONFACTORANDETRCALCULATIONTIMESTEPFOREACHSITEANDYEARATUTAHTURFLYSIMETERSITES,2002‐2008.
Site YearRs
CalibrationFactor
CalculationTimeStep
Comments
Logan 2002 1.025 Dailya Hourlyparametersnotsaved
2003b 1.012 Hourly
2004 1.010 Hourly
2005 1.006 Hourly
2006 1.002 Hourly
2007 1.004 Hourly
2008 0.997 Hourly
Murray 2002 0.994 Daily Hourlyparametersnotsaved
2003b 0.978 Hourly
2004 0.986 Hourly
2005 0.987 Hourly
2006b 0.971 Hourly
2007b 0.969 Hourly
2008b 0.979 Hourly
Southgate 2004b 1.048 Hourly
2005 1.032 Hourly 2006 1.049 Hourly 2007 1.017 Hourly 2008 1.048 Hourly
SpanishFork 2002c 0.980/1.086 DailyClimateCenterstationhadbadRH,dailydewpointlimitwasused
2003 1.086 Daily Hourlyparametersnotsaved 2004 1.087 Daily Hourlyparametersnotsaved 2005 1.081 Daily Hourlyparametersnotsaved
2006 1.070 Hourly
Sunbrook 2002b 1.045 Daily Hourlyparametersnotsaved
2003b 1.078 Hourly
2004 1.084 Hourly 2005 1.068 Hourly 2006 1.082 Hourly 2007 1.070 Hourly aAwindlimitof110miles/daywasusedforthedailycalculationsforLoganin2002.Thiswindlimitwasbasedoncalculationsfor2003to2008hourlyanddailyETrcalculationsusingdifferentdailywindlimits.bPartialyearofdataasfollows:Logan2003=1Febto31Dec,Murray2003=1Febto21Dec,Murray2006=1Aprto31Dec,
Murray2007=1Janto28Nov,Murray2008=26Janto31Dec,Southgate2004=23Junto31Dec,Sunbrook2002=22Febto31Dec,Sunbrook2003=29Janto31Dec.cSpanishFork2002includesdatafromaUtahClimateCenterweatherstationthroughday234,datafortheremainderoftheyearwasmeasuredbythecurrentweatherstation.Onlydailycalculationswereperformed,dewpointwassettobenomorethan4°FbelowTminintheClimateCenterstationdailycalculations.SpanishFork2002hastwoRscalibrations,onefortheClimateCenterstationandoneforthecurrentstation.Calculationsfor2002weredoneusingtheCRPSMWmodel.
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AcomparisonofASCEStandardizedPenman‐Monteithtallcrop(alfalfa)referenceET(ETrs)valuescalculatedusingbothdailyandhourlytimestepsisgiveninTable10forthefiveturflysimetersitesinUtah.Asnotedabove,onlydailycalculationtimestepswerepossiblein2002andatSpanishFork(exceptfor2006).TwosetsofwindandETrsvaluesareshowninTable10.Thefirst,denoted“Original”windrunorspeed,wasmadefromtheoriginalrecordedwindtravelandspeed,whereastheothercalculationofETrswasmadewith“Adjusted”winddata.Atemporaryco‐locationofelectronicweatherstationswithbothcuptype(MetOne014A)andpropellertype(R.M.Young05103)anemometerswasmadeintheSnowvilleareaaspartofanotherresearchstudy.Asaresult,wediscoveredthatthecuptypeanemometers(014A)givehigherwindvelocitiesthanthepropellertype(05103).FurthercalibrationchecksagainstaCSAT3sonicanemometerconfirmedthatthe014Areadhighandthe05103low.OnlySouthgateandSunbrook(Table2)havethepropellertype.ThisinfersthatETrsforSouthgateandSunbrookwouldberelativelylowerduetotheunderestimatedwindspeeds.Thus,thecalculatedcropcoefficient,withunadjustedwindspeed,wouldbehigherthanitshouldbe.Theconverseisthecasefortheothersites(Logan,MurrayandSpanishFork).InspectionofTable10indicatesthatthe“Original”averagewindtravelatLoganandMurrayisabout170andover125milesperday(mpd),respectively,andisabout100mpdatSpanishFork.WindtravelatSouthgateandSunbrookaveragesconsiderablylessatabout50and60mpd,respectively.ThecorrespondingdailytimestepcalculatedaverageannualETrsisabout79inchesatLogan,and64,58,64and70inches,respectively,atMurray,Southgate,SpanishForkandSunbrook.ThisillustratesthesensitivityoftheASCEStandardizedpenman‐Monteith,indeedanyPenmancombinationtypeETequation,towindspeed(orwindtravel).ThehighETrsatLogan,comparedwiththeconsiderablywarmersouthernUtahsitesissomewhatcounterintuitive.However,hourlytimestepcalculatedaverageannualETrsislowerthanthedailytimestepETrsvalueatsiteswiththehigherwindtravel,i.e.Logan(61in.vs.79),Murray(63in.vs.64)andSpanishFork(62in.vs.64).HourlycalculatedETrsishigherthandailyETrsatthelowerwindsitesofSouthgate(62in.vs.58)andSunbrook(71in.vs.70).Imposingthe“Adjusted”windreducestheETrsvaluesforthesiteswithcuptypeanemometers(Logan,MurrayandSpanishFork)whileincreasingcalculatedETrsatSouthgateandSunbrook,bothsiteswithloweraveragewind(Table10)andpropelleranemometers.Theneteffectofwindadjustmentforthehighwindsites(cupanemometers)wasabouta12%dropinwindtravel(Table10).Windtravelincreasedabout23%attherelativelylowwindsites(SouthgateandSunbrook)withtheadjustment.TheeffectofthewindadjustmentonETrswaslesspronounced.AnnualETrs,dailytimestepcalculation,averaged5%lessatthethreecupanemometer(014A)highwindsitesand10%moreatthetwopropelleranemometer(05103)lowwindsitesasaresultofthewindadjustmentcomparedtousingtheoriginalreportedwind.Similarly,hourlycalculatedETrsaveraged4%lessatthecupanemometer(014A)sitesand6%moreatthepropelleranemometer(05103)sites.
22
TABLE10:COMPARISONOFDAILYANDHOURLYCALCULATEDETRSVALUESWITHANDWITHOUTWIND
ADJUSTMENTSFOREACHSITEANDYEARATUTAHTURFLYSIMETERSITES,2002‐2008.CalculationsUsingDailyTimeStep CalculationsUsingHourlyTimeStep
AverageDailyWindRun(mpd)
AnnualETrsWith
OriginalWind
(inches)
AnnualETrsWithAdjustedWind
(inches)
AverageWindSpeed
(mph)
AnnualETrsWith
OriginalWind
(inches)
AnnualETrsWithAdjustedWind
(inches)
Site Year
Orig AdjASCEStd.
PMASCEStd.
PMOrig Adj
ASCEStd.PM
ASCEStd.PM
Logan 2002† 173 156 77.02 74.04 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2003* 185 168 81.80 78.63 7.69 6.99 62.08 60.07 2004 166 150 74.14 71.31 6.93 6.26 57.97 56.22 2005 162 146 74.55 71.67 6.76 6.09 58.07 56.29 2006 178 162 79.78 76.64 7.43 6.74 61.03 59.03 2007 171 154 84.01 80.61 7.11 6.43 65.30 63.09 2008 170 154 78.85 75.68 7.09 6.41 60.10 58.08 Average 172 156 78.59 75.51 7.17 6.49 60.76 58.80Murray 2002† 125 110 67.82 64.30 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2003* 128 113 66.59 63.08 5.34 4.70 65.70 63.12 2004 122 107 64.11 60.94 5.10 4.47 63.53 61.24 2005 128 113 64.24 61.09 5.33 4.70 62.57 60.35 2006* 124 109 57.78 54.81 5.15 4.52 56.29 54.12 2007* 125 110 68.81 65.21 5.22 4.60 67.81 65.17 2008* 121 106 61.01 57.68 5.01 4.38 59.68 57.23 Average 125 110 64.34 61.02 5.19 4.56 62.60 60.21Southgate 2004* 45 58 33.47 37.20 1.89 2.43 36.31 38.97 2005 44 57 60.47 67.06 1.84 2.38 65.84 70.47 2006 51 64 64.38 70.94 2.14 2.67 68.49 73.08 2007 54 67 67.13 73.89 2.24 2.77 71.67 76.48 2008 52 65 65.16 71.68 2.18 2.71 69.50 74.04 Average 49 62 58.12 64.15 2.06 2.59 62.36 66.61SpanishFork 2002** 107 93 64.34 59.84 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2003‡ 79 65 63.99 58.86 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2004‡ 94 80 61.91 57.87 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2005‡ 97 83 62.59 58.66 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2006 102 88 66.11 61.94 4.27 3.67 61.76 59.06 Average 96 82 63.79 59.43 4.27 3.67 61.76 59.06Sunbrook 2002*† 71 83 70.31 76.25 ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ ‐‐‐‐‐ 2003* 65 78 70.71 76.88 2.80 3.33 71.05 74.94 2004 65 78 71.19 77.25 2.72 3.24 72.29 76.16 2005 60 73 66.53 72.53 2.51 3.03 67.86 71.66 2006 62 75 68.45 74.89 2.60 3.12 69.05 73.29 2007 62 75 70.00 76.59 2.60 3.13 72.84 77.38 Average 64 77 69.53 75.73 2.65 3.17 70.62 74.69†In2002Logan,Murray,andSunbrookdidnotrecordnecessaryparametersforETrcalculationsonanhourlytimestep*Partialyearofdata,seeTable9footnoteb.**SeeTable9footnotec.‡SpanishFork2002hadoutputeveryhour,howeverdailycalculationsweredonefortheUtahClimateCenterstationdata,2003through2005hadoutputevery2hours.
23
LYSIMETERWATERBALANCEANDCALCULATEDKCRVALUES
LysimeterwaterbalanceandcalculatedcropcoefficientsweredeterminedforeachyearateachsitefortheperiodofcalculationaslistedinTables4through8.Anestimateofactual(measured)ETawasmadefromthelysimeterwaterbalance.Forthe2007annualreportseasonalturfgrassETcropcoefficients(alfalfareference,ETr)wereestimatedusingdailyandhourlycalculationtimestepsforETrfromtheASCEstandardizedPenmanMonteith(ASCEstPM)andthe1982KimberlyPenmanCombination(1982KimPen)Equations.Thefollowingdiscussionandfigureswereadaptedfromthatannualreport.ComparisonsofcumulativecalculatedETrandtheseasonprogressionofaccumulatedlysimeterwateruseandcorrespondingKcvaluesthroughouttheseasonsareillustratedinFigures7,8,and9,respectively,forLogan,Murray,andSouthgate.ThedifferenceinETbetweenthetwooldlysimeters(EastandWest)andthenewlysimeteratLoganisparticularlyevidentinFigure7a.TherewasmoredifferencebetweentheestimatedETforthetwolysimetersatSouthgate(Figure9)thanatMurray(Figure8).ThesumofcalculatedhourlyETrwaslowerthanthedailytimestepETrsum,exceptatSouthgate(Figure9a).ThemostdramaticdifferenceisatLogan(Figure7a)wherethehourlyASCEstPMETrwas24%lessthanthedailycalculatedvalue.ThisisattributedtothehighnighttimecanyonwindsatLogan.Generally,theASCEstPMETrvalueswerehigherthantheETrofthe1982KimPen.Earlyinthestudy,attemptsweremadetocalculateweeklycropcoefficientvalueswiththeassumptionthattheKcvaluemaybeabitlowerintheearlyspringthanduringthesummer.TheresultswereextremelyerraticwithcalculatedKcvaryingfromover2tonegativevaluesinsuccessiveweeks.ThiseffectissomewhatillustratedinFigure9bwherethecumulativelysimetercropcoefficientfluctuatesfrom0.85downtoabout0.6andthenincreasesagaininsuccessivecalculationperiodsintheearlyseason.Thismaybetheresultofatimingmismatchbetweenweeklymeasurementsandtheoccurrenceofrain,irrigationandsubsequentdrainage.Itisalsoanartifactofthecalculationprocedurewhichdoesnotaccountforsoilwaterdepletionandsubsequentrefill,becausesoilwatercontentwasnotmeasured.Similarly,theadditionofextrawatertotheMurraylysimetercauseda“jump”inthecalculatedETandinthecropcoefficient(Figure8).
24
FIGURE7A.CUMULATIVELYSIMETERETANDETRFORLOGANGOLFANDCOUNTRYCLUB,LOGAN,UTAH,2007
FIGURE7B.CUMULATIVELYSIMETERCROPCOEFFICIENTFORLOGANGOLFANDCOUNTRYCLUB,LOGAN,UTAH,2007
25
FIGURE8A.CUMULATIVELYSIMETERETANDETRFORMURRAYPARKWAYGOLFCOURSE,MURRAY,UTAH,2007
FIGURE8B.CUMULATIVELYSIMETERCROPCOEFFICIENTFORMURRAYPARKWAYGOLFCOURSE,MURRAY,UTAH,2007
26
FIGURE9A.CUMULATIVELYSIMETERETANDETRFORSOUTHGATEGOLFCOURSE,ST.GEORGE,UTAH,2007
FIGURE9B.CUMULATIVELYSIMETERCROPCOEFFICIENTFORSOUTHGATEGOLFCOURSE,ST.GEORGE,UTAH,2007
27
Asaresultofconsiderationsmentionedabove,theASCEStandardizedPenman‐MonteithEquationwasusedwithanhourlycalculationtimestephereintoestimateETr(denotedETrs).Cropcoefficient(Kc)valueswereobtainedbydividingthemeasuredseasontotalETabythecorrespondingETrs.Boththeactualmeasureddrainage,intherecords,andanadjusteddrainagevaluearereportedinthefollowingtables.Theadjusteddrainage(seeAppendixF)wasobtainedfromusingareasonableprovisionalcropcoefficientinthesoilwaterbalance(drainage)model.Logan
WaterbalancevaluesforthethreelysimetersatLoganaregiveninTable11.ThenewlysimeterETvariedfrom21.6(2004)to35.2inches(2007)andthecalculatedKcvariedfrom0.51to0.66,witha5‐yearaverageof0.59.TheEastlysimeterETvariedfrom14.5(2004)to30.3inches(2002)andKcvariedfrom0.33to0.61,witha7‐yearaverageof0.42.TheWestLysimeterETwassomewhatlower,varyingfrom11.2(2004)to21.2inches(2007)andKcvariedfrom0.27to0.44,witha7‐yearaverageof0.34.CalculatedhourlytimestepwithadjustedwindETrsvariedfrom41.3to54.8inches.Drainageadjustmentsweremadetothe2004and2005dataonnewlysimeterandeveryyearontheolderlysimeters,exceptfor2004ontheEastlysimeter.Thenew(East)lysimeterwasinstalledin2004becauseoftheseeminglylowKcvaluesobtainedfromthetwoolderlysimeters(particularlytheWestlysimeter),whichwereinstalledin1991,incomparisonwith2002and2003datafromothersites.Datacollectiononthenew(whichiseastoftheoldEast)lysimeterbeganinearlyMay2004(Tables4and11).ThedifferenceinestimatedETamongtheLoganlysimetersisclearlyevidentincomparingETaandKcvaluesfromthenewlysimeterwiththeWestlysimeter(Table11)andsomewhatwiththeEastlysimeter(after2003).ConsideringonlythenewlysimeterdatawouldsuggestusinganaverageKcvalueofabout0.6forturfgrass,whichisabout7%higherthanthepreviouslyusedvalueof0.56(Hill,1994).
Murray
TurfgrasswateruseontheMurrayEastlysimeter(Table12)variedfrom22.2(2008)to30.5inches(2005).CalculatedETrsvariedfrom41.5to56.8inches.EstimatedKcfortheEastlysimetervariedfrom0.46to0.74,witha7‐yearaverageof0.57.TheWestlysimeterETwassimilar,varyingfrom23.2(2007)to30.2inches(2007).TheobservedKcvariedfrom0.43to0.70,witha7‐yearaverageof0.57.TheaverageKcforallyearsoverbothlysimeterswas0.57.Thevalueof0.57fortheaverageKcisalmostidenticaltothecropcoefficientvalue(0.56)usedinpreviousestimatesofturfET.
28
TABLE11:LOGANGOLFANDCOUNTRYCLUBNEW,EASTANDWESTLYSIMETERFULLSEASONWATERBALANCEVALUESWITHSEASONALCALCULATEDCROPCOEFFICIENTSNewLysimeter
Calc.PeriodYear
Begin End
Irrig.+Rain(in)
WaterAdded(in)
MeasuredDrain.(in)
AdjustedDrain.(in)
ET(in)
ETrs(in)
Kc
2004 7‐May 18‐Oct 26.07 0 4.19 4.45 21.62 40.06 0.542005 15‐Mar 24‐Nov 36.13 0 8.00 9.71 26.42 52.23 0.512006 26‐Apr 8‐Nov 33.51 2.87 5.14 5.14 31.24 47.43 0.662007 5‐Apr 17‐Nov 36.67 1.73 3.12 3.19 35.21 54.80 0.642008 30‐Apr 21‐Nov 29.89 1.73 4.17 4.20 27.42 47.31 0.58
AverageKc= 0.59
EastLysimeter KcSt.Dev.= 0.07
Calc.PeriodYear
Begin End
Irrig.+Rain(in)
WaterAdded(in)
MeasuredDrain.(in)
AdjustedDrain.(in)
ET(in)
ETrs(in)
Kc
2002 25‐Mar 14‐Oct 45.03 0 13.91 14.69 30.34 50.01 0.612003 17‐Mar 13‐Oct 38.05 0 9.80 9.80 28.25 52.82 0.532004 7‐May 18‐Oct 23.14 0 8.65 8.65 14.49 40.06 0.362005 15‐Mar 24‐Nov 34.11 0 12.88 13.75 20.36 52.23 0.392006 26‐Apr 8‐Nov 29.49 0 11.86 13.03 16.46 47.43 0.352007 5‐Apr 17‐Nov 31.55 0.87 9.80 10.89 21.53 54.80 0.392008 30‐Apr 21‐Nov 24.37 0 7.76 8.63 15.74 47.39 0.33
AverageKc= 0.42
WestLysimeter KcSt.Dev.= 0.10
Calc.PeriodYear
Begin End
Irrig.+Rain(in)
WaterAdded(in)
MeasuredDrain.(in)
AdjustedDrain.(in)
ET(in)
ETrs(in)
Kc
2002 25‐Mar 14‐Oct 39.30 0 13.86 20.33 18.97 50.01 0.382003 17‐Mar 13‐Oct 34.13 0 13.29 13.53 20.60 52.82 0.392004 7‐May 18‐Oct 25.21 0 13.04 14.06 11.15 40.06 0.282005 15‐Mar 24‐Nov 36.13 0 19.99 22.22 13.91 52.23 0.272006 26‐Apr 8‐Nov 32.80 0 14.83 16.51 16.29 47.43 0.342007 5‐Apr 17‐Nov 33.69 0.58 12.93 13.03 21.24 54.80 0.392008 30‐Apr 21‐Nov 31.91 0 9.64 11.08 20.83 47.39 0.44
AverageKc= 0.35
KcSt.Dev.= 0.06
SiteAverage AverageKcforalllysimeters= 0.44
KcSt.Dev.foralllysimeters= 0.12
29
TABLE12:MURRAYPARKWAYGOLFCOURSEEASTANDWESTLYSIMETERFULLSEASONWATERBALANCEVALUESWITHSEASONALCALCULATEDCROPCOEFFICIENTSEastLysimeter
Calc.PeriodYear
Begin End
Irrig.+Rain(in)
WaterAdded(in)
MeasuredDrain.(in)
AdjustedDrain.(in)
ET(in)
ETrs(in)
Kc
2002 4‐May 14‐Oct 28.6 0 0 0 28.60 44.65 0.642003 15‐Apr 13‐Oct 26.15 2.17 0 0 28.32 48.75 0.582004 29‐May 15‐Nov 30.11 1.73 3.58 3.58 28.26 53.08 0.532005 25‐Apr 26‐Sep 24.31 9.09 2.89 2.89 30.51 41.46 0.742006 20‐Mar 25‐Sep 23.96 6.79 2.58 6.34 24.41 46.14 0.532007 2‐Apr 19‐Nov 26.65 4.33 0.64 3.15 27.83 56.75 0.492008 2‐Apr 19‐Nov 22.57 0 0.35 0.35 22.22 48.03 0.46
AverageKc= 0.57
WestLysimeter KcSt.Dev.= 0.09
Calc.PeriodYear
Begin End
Irrig.+Rain(in)
WaterAdded(in)
MeasuredDrain.(in)
AdjustedDrain.(in)
ET(in)
ETrs(in)
Kc
2002 4‐May 14‐Oct 28.80 0 0 0 28.80 44.65 0.652003 15‐Apr 13‐Oct 27.59 2.17 0.03 0.03 29.73 48.75 0.612004 29‐May 15‐Nov 30.98 0 3.02 3.02 27.96 53.08 0.532005 25‐Apr 26‐Sep 24.80 6.06 1.78 1.78 29.08 41.46 0.702006 20‐Mar 25‐Sep 26.73 3.47 2.75 3.89 26.31 46.14 0.572007 2‐Apr 19‐Nov 29.32 2.60 0.14 1.73 30.19 56.75 0.532008 2‐Apr 19‐Nov 23.59 0 0.36 0.36 23.23 54.03 0.43
AverageKc= 0.57
KcSt.Dev.= 0.09
SiteAverage AverageKcforalllysimeters= 0.57
KcSt.Dev.foralllysimeters= 0.09
TheMurraysuperintendentusedaKcof0.56asaguideinirrigationscheduling.Asnotedearlier,theirrigationamountatMurrayismoderatedtoavoidcreatingorworseningatroublesomewetspotinaheavytrafficareatowardtheendofthe16thfairway.AsaresulttheestimatedturfETwasessentiallythesameasirrigationplusrainfall.Thus,thesimilaritybetweenKcvaluesmaynotbecoincidental.Becauseoftheslightlydeficitirrigation,veryfewdrainageeventsoccurredforeachcalculationperiodatMurray;thusanyabnormaldrainagehadasignificanteffectonthecalculatedcropcoefficient.Thiswasevidentin2005,wherethecalculatedKcvaluesareconsiderablyhigherthanthevaluescalculatedforotheryears.Drainageadjustmentsweremadein2006and2007onbothlysimeters.
30
Southgate
EvapotranspirationestimatedfromwaterbalancevaluesatSouthgatevariedfrom19.7(2006)to40.2inches(2007)fortheEastlysimeterandfrom23.1(2006)to50.0inches(2007)ontheWest(Table13).CalculatedETrsforSouthgatevariedfrom36.9to74.7inches.EstimatedKcfortheEastlysimetervariedfrom0.48to0.55,witha5‐yearaverageof0.53.TheWestlysimeterKcwassomewhathigher,varyingfrom0.63to0.67,witha5‐yearaverageof0.65.AverageKcforallyearsoverbothlysimeterswas0.59.Drainageadjustmentsweremadeeveryyearexcept2006ontheEastlysimeterand2004ontheWest.Forreasonsthatarenotclear,ETontheWestlysimeterwassignificantlyhigherthanontheEast.Thusthe5‐yearaverageKc,0.53,fortheEastlysimeterisabout18%lowerthantheWestlysimeter’saverageKcof0.65.TheWestlysimeteraverageKcvalueof0.65forturfgrass,isabout16%higherthanthepreviouslyusedvalueof0.56(Hill,1994).TABLE13:SOUTHGATEGOLFCOURSEEASTANDWESTLYSIMETERFULLSEASONWATERBALANCEVALUESWITH
SEASONALCALCULATEDCROPCOEFFICIENTSEastLysimeter
Calc.PeriodYear
Begin End
Irrig.+Rain(in)
WaterAdded(in)
MeasuredDrain.(in)
AdjustedDrain.(in)
ET(in)
ETrs(in)
Kc
2004 11‐Jun 4‐Dec 35.71 0 13.70 13.98 21.73 41.29 0.532005 10‐Mar 2‐Dec 33.22 13.59 3.33 12.18 34.63 63.38 0.552006 23‐Jun 1‐Dec 23.81 0 4.13 4.13 19.68 36.59 0.542007 24‐Jan 29‐Dec 54.97 2.60 15.22 17.35 40.22 74.73 0.542008 7‐Feb 18‐Nov 46.58 0.00 12.54 13.16 33.42 69.14 0.48
AverageKc= 0.53
WestLysimeter KcSt.Dev.= 0.03
Calc.PeriodYear
Begin End
Irrig.+Rain(in)
WaterAdded(in)
MeasuredDrain.(in)
AdjustedDrain.(in)
ET(in)
ETrs(in)
Kc
2004 11‐Jun 4‐Dec 36.83 0 9.28 9.28 27.55 41.29 0.672005 10‐Mar 2‐Dec 41.91 7.81 10.23 9.47 40.25 63.38 0.642006 23‐Jun 1‐Dec 31.50 0 7.08 8.43 23.07 36.59 0.632007 24‐Jan 29‐Dec 69.48 1.73 19.51 21.17 50.04 74.73 0.672008 7‐Feb 18‐Nov 62.22 0 17.03 17.9 44.32 69.14 0.64
AverageKc= 0.65
KcSt.Dev.= 0.02
SiteAverage AverageKcforalllysimeters= 0.59
KcSt.Dev.foralllysimeters= 0.07
31
SpanishFork
TheSpanishForkNorthlysimeterETvariedfrom17.8(2002)to30.4inches(2004),asgiveninTable14.CalculatedETrsvariedfrom31.7to49.7inches.TheobservedKcfortheNorthlysimetervariedfrom0.51to0.63,witha5‐yearaverageof0.58.TheSouthlysimeterETwasaboutthesameasthatfortheNorthvaryingfrom14.2(2002)to29.9inches(2005).TheobservedKcvariedfrom0.45to0.61,witha5‐yearaverageof0.54.TheaverageKcforallyearsoverbothlysimeterswas0.56,whichisidenticaltothevaluepreviouslyused.NodrainageadjustmentswereneededforeitherlysimeteratSpanishFork.TABLE14:SPANISHFORKTURFPLOTNORTHANDSOUTHLYSIMETERFULLSEASONWATERBALANCEVALUESWITH
SEASONALCALCULATEDCROPCOEFFICIENTSNorthLysimeter
Calc.PeriodYear
Begin End
Irrig.+Rain(in)
WaterAdded(in)
MeasuredDrain.(in)
AdjustedDrain.(in)
ET(in)
ETrs(in)
Kc
2002 5‐Jun 3‐Oct 18.73 0 0.96 0.96 17.77 31.67 0.562003 30‐Apr 10‐Nov 20.35 4.62 2.29 2.29 22.68 44.87 0.512004 1‐Apr 10‐Nov 34.16 6.13 9.90 9.90 30.39 48.33 0.632005 22‐Mar 2‐Nov 40.28 4.01 14.90 14.90 29.39 49.72 0.592006 24‐Apr 11‐Oct 32.13 6.48 10.15 10.15 28.46 45.35 0.63
AverageKc= 0.58
SouthLysimeter KcSt.Dev.= 0.05
Calc.PeriodYear
Begin End
Irrig.+Rain(in)
WaterAdded(in)
MeasuredDrain.(in)
AdjustedDrain.(in)
ET(in)
ETrs(in)
Kc
2002 5‐Jun 3‐Oct 19.54 0 5.38 5.38 14.16 31.67 0.452003 30‐Apr 10‐Nov 22.93 4.62 5.09 5.09 22.46 44.87 0.502004 1‐Apr 10‐Nov 34.52 6.44 11.61 11.61 29.35 48.33 0.612005 22‐Mar 2‐Nov 35.04 6.18 11.35 11.35 29.87 49.72 0.602006 24‐Apr 11‐Oct 31.84 5.76 13.20 13.20 24.40 45.35 0.54
AverageKc= 0.54
KcSt.Dev.= 0.07
SiteAverage AverageKcforalllysimeters= 0.56
KcSt.Dev.foralllysimeters= 0.06
32
Sunbrook
WateruseontheSunbrookEastlysimetervariedfrom13(2004)to35.9inches(2005)andKcvariedfrom0.37to0.68,witha5‐yearaverageof0.49(Table15).TheWestlysimeterETwassimilar,varyingfrom13.8(2004)to35.5inches(2002).CalculatedKcvariedfrom0.33to0.64,witha5‐yearaverageof0.46.TheaverageKcforallyearsoverbothlysimeterswas0.47.TheserelativelylowKcvaluesmayreflectthedatacollectionissuesexperiencedatthissite.CalculatedETrsforSunbrookvariedfrom29.7to71.3inches.Thiswiderangecorrespondstothevariableseasonlengthfromyeartoyear.Drainageadjustmentsweremadein2005onbothlysimeters.ThehighestKcvalues(0.68and0.64)werederivedfortherelativelyshortcalculationperiod,lateJunethroughmid‐October,2006.TheaveragetwolysimeterKcvalueof0.66forthis21/2monthperiodisessentiallythesameastheKc(0.65)fromtheSouthgateWestlysimeter(Table13).TABLE15:SUNBROOKGOLFCOURSEEASTANDWESTLYSIMETERFULLSEASONWATERBALANCEVALUESWITH
SEASONALCALCULATEDCROPCOEFFICIENTSEastLysimeter
Calc.PeriodYear
Begin End
Irrig.+Rain(in)
WaterAdded(in)
MeasuredDrain.(in)
AdjustedDrain.(in)
ET(in)
ETrs(in)
Kc
2002 25‐Feb 5‐Nov 35.12 0 0 0 35.12 71.33 0.492003 3‐Feb 10‐Nov 31.28 0 1.06 1.06 30.22 71.07 0.432004 1‐Mar 29‐Jun 13.6 0 0.62 0.62 12.98 35.17 0.372005 18‐Jan 28‐Dec 39.93 6.5 5.02 10.54 35.89 70.69 0.512006 26‐Jun 16‐Oct 25.44 0 5.34 5.34 20.10 29.73 0.68
AverageKc= 0.49
WestLysimeter KcSt.Dev.= 0.12
Calc.PeriodYear
Begin End
Irrig.+Rain(in)
WaterAdded(in)
MeasuredDrain.(in)
AdjustedDrain.(in)
ET(in)
ETrs(in)
Kc
2002 25‐Feb 5‐Nov 35.46 0 0 0 35.46 71.33 0.502003 3‐Feb 10‐Nov 24.99 0 1.49 1.49 23.50 71.07 0.332004 1‐Mar 29‐Jun 13.78 0 0 0 13.78 35.17 0.392005 18‐Jan 28‐Dec 31.98 6.07 5.00 8.29 29.76 70.69 0.422006 26‐Jun 16‐Oct 23.50 0 4.62 4.62 18.88 29.73 0.64
AverageKc= 0.46
KcSt.Dev.= 0.12
SiteAverage AverageKcforalllysimeters= 0.47
KcSt.Dev.foralllysimeters= 0.11
33
ESTIMATEDMONTHLYTURFGRASSCROPCOEFFICIENTSDerivingKcrvaluesforshorterthanseasonaltimeperiodsresultedinpoorresultsduetothetemporalresolutionofthelysimeterdata(seepage23herein).However,attherequestoftheUtahDivisionofWaterResources,monthlyKcr,andsubsequentlyKco,valueswerecalculatedforfourofthelysimeters:Logan–New,SpanishFork–North,andbothSouthgatelysimeters.DatanearthebeginningandendofeachmonthwereadjustedinanattempttoattributemeasuredETtothecorrectmonth.Forexample:ifalysimeterreadingwasmadewithinthefirstfewdaysofthemonthandnoreadingwasmadeonthelastdayortwoofthepreviousmonththedatawasproratedbetweenthe2monthsusingthenumberofdaysinthemeasurementinterval.FurtheradjustmentsweremadetothedatauponfinalanalysisbydiscardingobviousoutliersfromtheaveragemonthlyKcvalues.AlfalfaReference,ETrs,BasedCropCoefficientsTheyear‐to‐yearvariationinmonthlyKcrvaluesatthefourlysimetersisshowninFigures10through13.Althoughtherewasconsiderabledeviationinsomepoints(“outliers”),i.e.November2006,LoganNew(Fig.10);September2002and2003andMarch2005,SpanishForkNorth(Fig.11);December2006,SouthgateEast(Fig.12)andDecember2004,SouthgateWest(Fig.13),therewasgeneralagreementintrendsduringtheseason.
FIGURE10.MONTHLYKCRVALUESFORTHELOGANNEWLYSIMETER,2004‐2008
34
FIGURE11.MONTHLYKCVALUESFORTHESPANISHFORKNORTHLYSIMETER,2002‐2006.
FIGURE12.MONTHLYKCVALUESFORTHESOUTHGATEEASTLYSIMETER,2004‐2008.
35
FIGURE13.MONTHLYKCVALUESFORTHESOUTHGATEWESTLYSIMETER,2004‐2008.AverageKcrvaluesforeachmonthatthefourlysimetersareshowninFigures14through17.ThedashedlinesinthefiguresrepresenttheseasonalsuggestedKcrvaluesforthelocation.SeasonalKcrvalueswere0.6forLoganandSpanishForkand0.65forSouthgate.TheoutlyingdatapointswerenotincludedinFigures14through17.
FIGURE14.AVERAGEKCVALUESFOREACHMONTHFORTHELOGANNEWLYSIMETER..OBVIOUSOUTLIERSWERE
EXCLUDED.THEDASHEDLINEREPRESENTSTHESUGGESTEDFULLSEASONKCR.
36
FIGURE15.AVERAGEKCVALUESFOREACHMONTHFORTHESPANISHFORKNORTHLYSIMETER.OBVIOUS
OUTLIERSWEREEXCLUDED.THEDASHEDLINEREPRESENTSTHESUGGESTEDFULLSEASONKCR.
FIGURE16.AVERAGEKCVALUESFOREACHMONTHFORTHESOUTHGATEEASTLYSIMETER.OBVIOUSOUTLIERS
WEREEXCLUDED.THEDASHEDLINEREPRESENTSTHESUGGESTEDFULLSEASONKCR.
37
FIGURE17.AVERAGEKCVALUESFOREACHMONTHFORTHESOUTHGATEWESTLYSIMETER.OBVIOUSOUTLIERS
WEREEXCLUDED.THEDASHEDLINEREPRESENTSTHESUGGESTEDFULLSEASONKCR.
ThevaluesinFigures14and15werecombinedtoobtainanaverageforthehigherelevationregionsofthestate.TheresultsofthiscomparisonalongwithasuggestedseasonallyvaryingcropcoefficientcurveareshowninFigure18.Asimilarcurve,Figure19,wasdevelopedforthelowelevationsouthernregionofthestate.
FIGURE18.SUGGESTEDKCCURVEFORTHEHIGHERELEVATIONAREASOFUTAH.MONTHLYKCVALUESAVERAGED
BETWEENTHELOGANNEWANDSPANISHFORKNORTHLYSIMETERS.OBVIOUSOUTLIERSWEREEXCLUDED.
38
FIGURE19.SUGGESTEDKCCURVEFORTHELOWELEVATIONAREASOFSOUTHERNUTAH.MONTHLYKCVALUES
AVERAGEDBETWEENTHETWOSOUTHGATELYSIMETERS.OBVIOUSOUTLIERSWEREEXCLUDED.ThecropcoefficientsshowninFigures18and19arereasonableKcrcurvesfordifferentregionsofUtah.ThecurveinFigure18representsthemajorityofthestate(excepttheSouthernLowelevationregionofUtah’sDixie).ThecurvesuggestedinFigure18beginswithavalueof0.45startingatturfgreenuporabsenceofsnowinthespring(aroundthebeginningtomiddleofMarchformanyareas).TheKcrremainsat0.45forabout20daysuntillateMarchwhentheturfbeginsactivegrowth.TheKcrvaluethenincreaseslinearlyforabout30daystoavalueof0.60whentheturfreachesfullleafareaandgrowth(typicallyneartheendofApril).TheturfKcrremainsat0.60forthedurationoftheseasonuntilcoolfalltemperaturesresultinreducedturfgrowthrates.Thisistypicallyaroundmid‐October,afterwhichKcrdecreaseslinearlytoward0.45inearlyNovemberandremainsatthatvalueuntildormancy.TheKcrcurveforUtah’sDixie,Figure19,issimilartothatofFigure18,however,itcontinuesforthefullyearandisshiftedupbyabout0.05.TheKcrbeginsinJanuaryatavalueof0.50duringthesemi‐dormantperiod.InlateFebruarytoearlyMarchtheKcrvaluebeginstoincreaselinearlytowardavalueof0.65,typicallyreachedafterabout30daysorwithinthefirstweekofApril.TheKcrvalueremainsat0.65forthemajorityoftheseasonuntilthegrowthslowsinlatefall.ThisoccursinmidtolateOctoberandtheKcrvaluedecreaseslinearlytowardavalueof0.50,whichistypicallyreachedinmid‐November,andremainsat0.50untilthefollowingspring.Inbothsetsofsuggestedcropcoefficientcurves,Figures18and19,maintainingthemid‐seasonKcrataconstantvalue,0.60or0.65,ignorestheindicationofa“summerslump”inturfwateruse.
39
GrassReference,ETos,CropCoefficients
CalculatedvaluesofETforagrassreference,EToarelowerthanthoseforanalfalfareferenceby10to25%orso(Jensen,etal.,1990).Asaresult,grassreferencebasedcropcoefficient,Kco,valuesarecorrespondinglygreaterthanalfalfabasedcropcoefficients,Kcr.Typically,multiplicationfactorsonETorangingfrom1.15to1.25havebeenusedtoapproximateETr(forexample,ETr=1.2ETo).ThecropcoefficientvaluesforETrspresentedaboveshouldbemultipliedbyafactorapproximatelyequalto1.2torelatetoanASCEStandardizedgrassreference,ETos,basis.Thus,themid‐seasonKcovaluesare0.72(0.72=1.2x0.6)forhigherelevationsandnorthernUtah.Similarly,amid‐seasonKcovalueof0.78(0.78=1.2x0.65)wouldbeindicatedforthesouthernandlowerelevationpartsofthestate.TheearlyandlateseasonKcovaluesbecome0.48and0.60,respectively,forthenorthernhigherelevationandsouthernlowerelevationsites.Mid‐seasonKcovaluesof0.70fornorthernUtahandhigherelevationsand0.80forsouthernUtahandlowerelevationsareobtainedfromroundingthesevaluestothenearest0.05.CorrespondingearlyandlateseasonKcovaluesare0.50and0.60,respectively,forthenorthernhigherelevationandsouthernlowerelevationsites.TheresultingcropcoefficientcurvesareshowninFigures20and21.
FIGURE20.SUGGESTEDKCOCURVEFORTHEHIGHERELEVATIONAREASOFUTAHALONGWITHKCOVALUESFOR
EACHMONTHAVERAGEDBETWEENTHELOGANNEWANDSPANISHFORKNORTHLYSIMETERS.ADAPTEDFROM
FIGURE18.
40
FIGURE21.SUGGESTEDKCOCURVEFORTHELOWELEVATIONAREASOFSOUTHERNUTAHALONGWITHKCO
VALUESFOREACHMONTHAVERAGEDBETWEENTHETWOSOUTHGATELYSIMETERS.ADAPTEDFROMFIGURE19.
41
SUMMARYANDCONCLUSIONSObservedseasonalturfgrassconsumptiveusevariedfrom11.2inches(LoganWest,2004,Table11)to50.0inches(Southgate,2007,Table13).TherangeatLogan(Table11)was11.2(West,2004)to35.2inches(New,2007);atMurray(Table12),22.2(East,2008)to30.5inches(East,2005);atSouthgate(Table13),19.7(East,2006)to50.0inches(West,2007);atSpanishFork(Table14),14.2(South,2002)to30.4inches(North,2004)and13.0(East,2004)to35.5inches(West,2002)atSunbrook(Table15).DirectcomparisonofsuchvariationinETvaluesacrossyearsandsitesisproblematicduetodifferinggrowingseasonlengthsfromyeartoyear,siteenvironmentalconditions(averagetemperaturesandwindpatterns),andelevation(rangeof2600to4800ftabovemsl)fromsouthtonorthinUtah(Latituderangeof37°Nto42°N).Therewasconsiderableyeartoyearandlysimetertolysimetervariation.TheyeartoyearvariationwasmoreevidentatSouthgateandSunbrook,dueperhapstothelargervariationincalculationperiodsthanattheothersites.ThelysimetertolysimetervariationwasparticularlynoticeableatLogancomparingtheWestlysimetertoboththeNewandtheEastlysimeters.TherewasalsoafairdifferencebetweenthetwolysimetersatSouthgate.ThevariationinrainplusirrigationthatisevidentinTables11‐15betweenlysimetersatagivensiteillustratesnon‐uniformityofirrigationasthereisproportionatelylesservariationinthemagnitudeofrainamounts.Itwasalsoaperplexingdataanalysisissue.Themulti‐yearaverageseasonalobserved(basedonlyonindividuallysimeterET)cropcoefficientvaluesvariedfrom0.34(LoganWest)to0.65(SouthgateWest).SingleseasonKcvaluesof0.74and0.70werecalculated,respectively,fortheEastandWestMurraylysimetersin2005,buttheseseemanomalousandmaybeduetodrainagemeasurementproblems.Ashortperiod,2‐1/2month,lysimeteraverageKcof0.68wasobtainedatSunbrookEast(2006).StudyperiodaverageseasonalKcvaluesbylysimeterwere:Logan0.59(New),0.42(East),0.34(West)andsiteaverageof0.45;Murray0.57(bothEastandWest)andsiteaverageof0.57;Southgate0.53(East),0.65(West)andsiteaverageof0.59;SpanishFork0.58(North),0.54(South)andsiteaverageof0.56andSunbrook0.49(East),0.46(West)andsiteaverageof0.47.AveragetwolysimeterseasonalKcvaluesatMurrayandSpanishForkweresimilar(0.57and0.56,respectively)althoughtherewaslessacrossyearvariationatSpanishFork.IgnoringtheolderlysimetersatLogan,the5‐yearseasonalaverageKcrontheNewlysimeterofabout0.60mayreasonablyrepresentawell‐wateredturfgrass,cuttingheightof1.5to2inches,inthecentralandnorthernpartsofthestate,whereastheSouthgateWestlysimeter5‐yearseasonalaverageKcrof0.65wouldsimilarlybereasonabletouseinthelowerelevationandwarmersouthernUtah.TheseKctvalues,0.60and0.65,are,respectively,about7%and16%higherthantheKcof0.56usedinearlierestimatesofturfgrassevapotranspirationacrossUtah(Hill,1994).
42
FurtheranalysiswasconductedtoderivemonthlyKcrandsubsequentlyKco,valuesforfourofthelysimeters:Logan–New,SpanishFork–North,andbothSouthgatelysimeters.LysimeterETdatanearthebeginningandendofeachmonthwereproratedbetweenthe2monthsusingthenumberofdaysinthemeasurementinterval.FurtherdataadjustmentsweremadeuponfinalanalysisbydiscardingobviousoutliersfromtheaveragemonthlyKcvaluesTheturfgrasscropcoefficientforthemajorityofthestate(exceptlowelevationsouthernUtah)beginswithavalueof0.45startingatturfgreenuporabsenceofsnowinthespring(aroundthebeginningtomiddleofMarchformanyareas).TheKcrremainsat0.45forabout20daysuntillateMarchwhentheturfbeginsactivegrowth.TheKcrvaluethenincreaseslinearlyforabout30daystoavalueof0.60whentheturfreachesfullleafareaandgrowth(typicallyneartheendofApril).TheturfKcrremainsat0.60forthedurationoftheseasonuntilcoolfalltemperaturesresultinreducedturfgrowthrates.Thisistypicallyaroundmid‐October,afterwhichKcrdecreaseslinearlytoward0.45inearlyNovemberandremainsatthatvalueuntildormancy.TheKcrcurveforUtah’sDixieissimilar;however,itcontinuesforthefullyearandisshiftedupbyabout0.05.TheKcrbeginsinJanuaryatavalueof0.50duringthesemi‐dormantperiod.InlateFebruarytoearlyMarchtheKcrvaluebeginstoincreaselinearlytowardavalueof0.65,typicallyreachedafterabout30daysorwithinthefirstweekofApril.TheKcrvalueremainsat0.65forthemajorityoftheseasonuntilthegrowthslowsinlatefall.ThisoccursinmidtolateOctoberandtheKcrvaluedecreaseslinearlytowardavalueof0.50whichistypicallyreachedinmid‐Novemberandremainsat0.50untilthefollowingspring.Inbothsetsofsuggestedcropcoefficientcurves,maintainingthemid‐seasonKcrataconstantvalue,0.60or0.65,ignorestheindicationofa“summerslump”inturfwateruse.Grassreference‐basedcropcoefficient,Kco,valueswerederivedfromKcrbymultiplyingKcrbyabout1.2.Thus,themid‐seasonKcovaluesare0.72(0.72=1.2x0.6)forhigherelevationsandnorthernUtah.Similarly,amid‐seasonKcovalueof0.78(0.78=1.2x0.65)wouldbeindicatedforthesouthernandlowerelevationpartsofthestate.TheearlyandlateseasonKcovaluesbecome0.48and0.60,respectively,forthenorthernhigherelevationandsouthernlowerelevationsites.Mid‐seasonKcovaluesof0.70fornorthernUtahandhigherelevationsand0.80forsouthernUtahandlowerelevationsareobtainedfromroundingthesevaluestothenearest0.05.CorrespondingearlyandlateseasonKcovaluesare0.50and0.60,respectively,forthenorthernhigherelevationandsouthernlowerelevationsites.
43
REFERENCESAllen,R.G.,J.PruegerandR.W.Hill.1992.Evapotranspirationfromisolatedstandsof
hydropytes:cattailandbulrush.Trans.ASAE35(4):1191‐1198.Allen,R.G.andJ.L.Wright.2002.ConversionofWright(1981)andWright(1982)alfalfa‐based
cropcoefficientsforusewiththeASCEStandardizedPenman‐MonteithReferenceEvapotranspirationEquation.TechnicalNote.USDA‐ARSKimberly,ID.December.
Allen,R.G.,I.A.Walter,R.Elliot,T.A.Howell,D.ItenfisuandM.E.Jensen.2005.TheASCE
StandardizedReferenceEvapotranspirationEquation.TaskCom.onStandardizationofReferenceEvapotranspiration,EWRI,ASCE.Reston,VA.
Dlamini,M.V.D.2003.Short‐TermWaterUseDynamicsinDrainageLysimeters.Unpublished
PhDDissertation.UtahStateUniversity,Logan,UtahErvin,E.H.andA.J.Koski.1998.DroughtAvoidanceAspectsandCropCoefficientsofKentucky
BluegrassandTallFescueTurfsintheSemiaridWest.CropScience38:788‐795.Hill,R.W.,C.E.Brockway,R.D.Burman,L.N.AllenandC.W.Robison.1989.DutyofWater
UndertheBearRiverCompact:FieldVerificationofEmpiricalMethodsforEstimatingDepletion.FinalReport.UtahAgricultureExperimentStationResearchReportNo.125.UtahStateUniversity,Logan,Utah.January.
Hill,R.W.1994.ConsumptiveuseofirrigatedcropsinUtah,UtahAgriculturalExperiment
StationResearchReportNo.145,UtahStateUniversity,Logan,UT,Oct.370p.RevisedFeb.1997,reprinted.AlsoonplacedontheWebathttp://nrwrtl.nr.state.ut.us/techinfo/consumpt/default.htm
Hill,R.W.,A.Gonzalez‐Mesa,L.N.Allen,andR.Oldham.1997.Turfgrasswateruseforan
IntermountainGolfCourse.PresentedattheSep.18‐20,PNWRegionMeeting,PaperNo.PNW97‐108,ASAE2950NileRoad,St.Joseph,MI49085‐9659.
Jensen,J.E.,R.D.BurmanandR.G.Allen(Eds.)1990.EvapotranspirationandIrrigationWater
Requirements.AmericanSocietyofCivilEngineers,345East47thStreet,NewYork,NY10017‐2398.ASCEManualNo.70.
Quinlan,P.,R.BurmanandE.Siemer.1982.Insitulysimeterinstallation.ASAETech.Paper82‐
2015.AmericanSocietyofAgriculturalEngineers,St.Joseph,MI.
Wright,J.L.1982.NewEvapotranspirationCropCoefficients.JournalOfIrrigationAndDrainageDivision.ASCE,Vol.108,pp.57‐75.
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Wright,J.L.,R.G.Allen,T.A.Howell.2000.ComparisonBetweenEvapotranspirationReferencesandMethods.pages251‐259inEvans,R.G.,B.L.Benham,andT.P.Trooien(ed.)ProceedingsoftheNationalIrrigationSymposium.ASAE,Nov.14‐16,2000,Phoenix,AZ.
45
APPENDICESAPPENDIXA:WorkTasksbyObjective
A.Determineturfgrasswaterusebymeasurementwithlysimeters.
USU:1.Arrangeforfabricationandtransportlysimeterseachsite.2. Superviseinstallationoflysimetersateachsiteandprovideoverallsupervisionof
project.3. Trainpersonnelateachsiteinirrigationprecipitation,weather,andlysimeterdata
collectionanddatatransferprotocol.4. Receiveweeklye‐mailedlysimeterdatareportsfromeachsite,enterintospreadsheet
andperformpreliminaryqualitycontrolanalysis.5. Performweeklypreliminarydataanalysisforqualitycontrolforallsites,collect
lysimeterandweatherdataatLogansite.6. Prepareannualprogressreports.Analyzeavailableweatherdatafromelectronic
weatherstationsandassociatedNWSstationsandprepareconsistentdailyandmonthlydatasetsandshareinterimresultsasappropriate.
7. Provideongoingtrainingandsupervisionasneeded.8. PerformdetailedanalysisoffirsttwoyearsoflysimeterdataafterNovember2002and
prepareinterimturfgrasscropcoefficientandwateruserecommendations.9. PreparefinalreportsummarizingthelysimeterdatafromCacheValley,southSaltLake
County,UtahCounty,andWashingtonCounty.
BYU:1.PerformlysimeterdatacollectionatBYUturfplotsbeginninginearlyMarchand
continuingthroughNovember.Thefrequencyshouldbeatleastonceperweekinspringandfallandtwice(orthreetimes)perweekinthesummer.
2. Collectothersitedataasappropriate(seeAnnex).3. E‐mailcurrentdatatoUSUeachweek.4. Reviewreports,providesuggestionsforimprovement.
B. Analysisofpreviouslycollectedturfgrassirrigationandsoilwatercontentdata.
BYU:1. Locateandorganizearchiveddata.2. Transmitinelectronicformat(standardDOS‐ASCIIorExcelorQuattro)toUSUBIE
personnel.3. Reviewpreliminaryresultsanddraftoffinalreport.
USU:1. Review,screen,andperformdetailedanalysisofneutronprobe,irrigation,
precipitation,andweatherdataasreceivedfromBYU.2. Preparesummaryreportoffindings.
46
APPENDIXB:TurfLysimeterDataCollectionProtocolThepurposeofthisprotocolistoformalizeturfgrasslysimeterdatacollectionprocedures.Thiswillaidinobtainingturfgrasswateruseunderwell‐wateredconditions.Well‐wateredconditionsareassuredonlyifdrainageoccursfromtimetotime.I. DataCollectionProcedureandObservations
A. Raingage
Theraingagetopfunnelshouldberemoved.Theinnermeasurementcylindershouldbetakenoutandheldupsuchthatthewatersurfaceisateyelevel.Theamountofwater(hundredthsofinches)shouldberecordedonthedatasheet.Ifmorethan1inchofirrigationandprecipitationoccurs,theinnercylindershouldbedumped(equals1inchatoverflow),andwaterpouredintoitfromtheraingagetogetthereading.Thetotaldepthshouldberecordedonthedatasheet.
B. DrainageBucket Thebucketshouldberemovedfromthemanholewell,andsetonalevelsurface
(perhapsthemanholelid).Thedepthofwatershouldbemeasuredwithatapemeasuretothenearest1/16inchintwodiametricallyoppositesidesofthebucket(toallowfornon‐level).Thetwodepths(h1,h2)shouldberecordedonthedatasheet.Alternately,agraduatedcylindercouldbeusedtoobtainwatervolumesinplaceofthetwodepthmeasurements.
C. DataSheet
EastLysimeter WestLysimeter Date
RainGageDepth Drainagebucketdepth(inch)
RainGageDepth Drainagebucketdepth(inch)
NW(inch)
SE(inch) h1,h2 Avg NW(inch) SE(inch) h1,h2 Avg
Comments
47
D. DataCollectionInterval.
Datashouldbecollectedfromtheraingagesanddrainagebucketforeachlysimeteratleastonceperweek.However,ifthedrainagebucketsareallowedtooverflow,thewaterbalancemeasurementwillbelostforthattimeperiod.Thus,thelysimeterdatacollectionintervalmayneedtobe2or3days,ratherthanonceperweek,ifabundantdrainageisoccurringormayoccurduetoheavyrainorirrigation.
Atthetimeofdatacollection,cleananygrassleavesthatmaybeencroachingontheraingageouterpipes.Also,noteanyconditionsthatmayaffectdataaccuracy.
II. SpringtimeDataCollectionInitiation(exceptatSt.George,whichisyearround) Assoonasthesnowhasmelted,theraingagesshouldbecleanedandplacedinanuprightpositionwiththetopasclosetolevelaspossibleandabout1inchbelowthegroundsurface.Anygrassshouldbetrimmedawayfromtheinsideofraingageaccesspipe(6inchPVC).Thedrainagebucketsshouldalsobeplacedunderthedrainpipe.Thedateandtimeofstart‐upshouldberecordedandfaxed[(435)797‐1248]ore‐mailed([email protected])toR.W.Hill. Withinadayortwo,checkthedrainagebucketforanydrainagewater.Ifnodrainageoccurs,thenameasuredquantityofwater(15gallons)shouldbeaddedtoeachlysimeter.Ifthesoilismoist,thedrainagebucketsshouldbecheckedin30minutes.Anydrainageshouldbenotedandmeasuredifmorethan1/3full,andthebucketsemptied.Usejudgmenttoestimatewhenthebucketsshouldbecheckedagaintoavoidoverflow.III. GrowingSeasonObservations Weeklylysimeterdatacollectionvisitsshouldbegininthespringandcontinuethroughoutthesummerandfall.Dependingontheamountofdrainage,thevisitsmayneedtobetwiceweeklytoavoidhavingadrainagebucketoverflowinbetweenobservations.Ateachvisit,datashouldbecollectedasdescribedinSectionI.Thedatasheetshouldbefaxedto[(435)797‐1248]toR.W.Hill,every2or3weeks. Itisimportanttothepurposeofthestudythatadequatewaterbeappliedtothelysimeters.Thus,somedrainageisnecessarytoensure“well‐watered”conditionshavebeenrealized.Ifdrainageisnotoccurringeachweek,thentheadditionofextrawatertoeachlysimetermustbedone.Ifnodrainageoccurs,thenameasuredquantityofwater(15gallons)shouldbeaddedtoeachlysimeter.Ifthesoilismoist,thedrainagebucketsshouldbecheckedin30minutes.Anydrainageshouldbenotedandmeasuredifmorethan1/3full,andthebucketsemptied.Usejudgmenttoestimatewhenthebucketsshouldbecheckedagaintoavoidoverflow.Also,thisprocedureshouldbefollowedtoinducedrainageattheendofeachmonth(April,May,June,July,AugustandSeptember)ifnootherdrainagehasoccurred.
48
IV. WinterShutDown(exceptatSt.George) Theraingageshouldbeturnedupsidedown,orremovedfromthefield,whentemperaturesbecomecoldenoughtocausefreezingdamage.Themeasurementshouldbediscontinuedifsignificantsnowfalloccurs.Thedrainagebucketscouldbeleftinplacealittlelonger,withoutfrostdamage.Although,theyeventuallyshouldalsobeturnedupsidedownwhenairtemperaturesdropbelowabout20°F.
49
APPENDIXC:WeatherStationSensorsandObservationParametersEachelectronicweatherstationincludedaCampbellScientificdatalogger(CR10XatLogan,Murray,SouthgateandSunbrookandCR10atSpanishFork)andthefollowingsensors:
• TwoCampbellScientific107TemperatureProbes,oneforairandoneforsoiltemperature
• VaisalaHMP45CRelativeHumidityProbe• LICORLI200sSiliconPyranometer,forsolarradiation• MetOne014AAnemometerandMetOne024AWindDirectionSensor(atLogan,
MurrayandSpanishFork)orRMYoung05103WindMonitor(atSunbrookandSouthgate),forwindspeedandwinddirection
Thedataloggerscannedthevariousinputsensorsonceevery10seconds.Theseobservationswereprocessedandoutputasdaily(midnighttomidnight)andhourlyvalues.Theparametersoutputeachhourandeach24hourperiodwere:
Hourly• Averageairtemperature• Maximumairtemperature• Minimumairtemperature• Averagerelativehumidity• Totalsolarradiation• Averagewindspeed• Averagewinddirection• Averagesoiltemperature
24Hour(oncedaily)Output
• Maximumairtemperature• Minimumairtemperature• Maximumrelativehumidity• Minimumrelativehumidity• Totalsolarradiation• Totalwindrun• Averagewinddirection• Averagesoiltemperature
50
APPENDIXD:SummaryofDataCollectedatLogan,1991‐2001TABLED1:SEASONALTOTALIRRIGATION,DRAINAGEANDTURFWATERUSE,1991‐95,2000‐01,FROMTWO
LYSIMETERSINTHELOGANGOLFANDCOUNTRYCLUB,LOGAN,UTAH.PARTIALSEASONDATAFOR1996‐99 EastLysimeter WestLysimeter
Year SeasonIrrigation+rain,in
Drainagein
ETin
Irrigation+rain,in
Drainagein
ETin
AverageET,
inches
1991 03Apr‐28Oct 38.95 6.81 32.14 38.00 13.94 24.06 28.101992 15Apr‐27Oct 28.29 0.18 28.11 28.69 2.97 25.72 26.921993 16Apr‐26Oct 30.77 6.36 24.41 34.87 15.75 19.12 21.771994 11Apr‐28Oct 35.08 3.94 31.14 37.80 14.71 23.08 27.101995 17Apr‐02Oct 27.48 1.59 25.89 32.17 11.06 21.11 23.502000 06Apr‐06Nov 35.70 2.11 33.59 32.73 8.67 24.06 28.832001 15Mar‐19Nov 44.24 11.39 32.84 42.08 20.64 21.44 27.14
SevenYearAverage 34.36 4.63 29.73 35.19 12.53 22.66 26.19
1996b 09May‐14Nov 25.93 3.75 22.18 27.64 8.46 19.18 20.681997b 09May‐03Dec 25.52 6.47 19.05 13.25 4.75 8.50 13.781998b 16Apr‐11Nov 22.61 2.87 19.74 15.91 5.39 10.52 15.131999b 11May‐08Sept 17.97 0.66 17.31 8.73 1.57 7.16 12.24
aThetwolysimetersarelocatedattheLoganGolfandCountryClubinaroughbetweentheholeoneandthreefairwaysandadjacenttothegreensnurseryarea.Theelectronicweatherstation(CampbellScientific,Inc.)iswestofthegreensnurseryandabout30feettothenorthoftheeastlysimeter.bSomedrainagerecordslostduetobucketoverflow.
51
TABLED2:TURFGRASSWATERUSE(ET)ANDCROPCOEFFICIENTS(KCM),1991‐95,AND2000‐01,FROM
LYSIMETERSATTHELOGANGOLFANDCOUNTRYCLUB,LOGAN,UTAH.PARTIALSEASONDATAFOR1996‐99
EastLysimeter WestLysimeter
Year ETrInchesET,inches Kcm
ETrinches
ET,inches Kcm
SeasonalaverageKcm
1991 43.06 32.14 0.75 43.06 24.06 0.56 0.651992 48.82 28.11 0.58 48.82 25.72 0.53 0.551993 47.36 24.41 0.52 47.36 19.12 0.40 0.461994 52.00 31.14 0.60 52.00 23.08 0.44 0.521995 40.75 25.89 0.64 40.75 21.11 0.52 0.582000 48.37 33.59 0.69 48.37 24.06 0.50 0.602001 47.53 32.84 0.69 47.53 21.14 0.45 0.57SevenyearAverage 46.84 29.73 0.63 46.84 22.61 0.48 0.56 1996 33.90 22.18 0.65 32.91 19.18 0.58 0.621997 40.77 19.05 0.47 20.84 8.50 0.41 0.441998 28.56 19.74 0.69 21.70 10.52 0.49 0.591999 27.17 17.31 0.69 16.93 7.16 0.42 0.53ElevenYearAverage 0.63 0.48 0.56
1. WeatherDatafor1996wasobtainedfromLoganUSUStation2. 1995datastartedfromMayinsteadofApril3. For1996,97,98and1999somedrainagerecordslostduetobucketoverflow
52
APPENDIXE:CorrectionsMadetoWeatherData
Logan2002 Dailycalculationsonlyweredoneforthewholeyear,Day35hour1500appearstwicewith
differentdatathefirstwasdeleted.2003 Dailycalculationsonlyweredonefordays1–31,Day31valueswereerroneousexceptfor
maximumtemperature;allothervaluesweretakenasanaverageofDays30and32.2007 Day95hour1100wastakenasanaverageofhours1000and1200,Day304hours600and700
appearedtwicewithdifferentdatathesecond600andfirst700weredeleted.2008 Day86,hour600wasmissing(daylightsavingsshift)anaverageofhours500and700wasused
tocreatea600dataset.Day309hour900appearedtwice(daylightsavingsshift)tookaverageofbothlinesandusedit.
Murray2003 Dailycalculationsonlyweredonefordays1–30,Day30hadsomeerroneousvaluesfor
minimumtemperature,relativehumidity(maxandmin)andsolarradiation;thesevaluesweretakenasanaverageofdays29and30.
2004 Day336hour600datawasduplicated,oneoftheselineswasdeleted2005 Day303hour900appearedtwicewithdifferentdatathefirstwasdeleted.2006 Day42haderrorvaluesforminimumtemperatureandrelativehumidityassoiltemperature;
averagevaluesfromdays42and44wereused.OnDay100thedaywasfalselyincrementedupbyoneuntilDay103(whichappearedtwice)thiswascorrected.Thissameerrorwascorrectedbetweendays142and150.Day101hour2300wasestimatedasanaverageofhours2200and2400.
2007 Day333datawasreplacedwiththeaverageofDays332and334.2008 DatauptoDay25,hour600,was6hourdataduetoanaccidentalprogramalteration.Data
fromDay25,hour1500onwashourly,dailycalculationswereusedforDays1–25.DailywindandsolarradiationvaluesforDay25weretakenasanaverageofDays24and26,becausetheprogramchangecausedalossoftemporarydataintheloggeronDay25.Day72,hour600wasmissing(daylightsavingsshift)anaverageofhours500and700wasusedtocreatea600dataset.Day311hour700appearedtwice(daylightsavingsshift).Tookaverageofbothlinesandusedit.
Southgate2004 Day303hour900appearedtwicewithdifferentdata.Thefirstwasdeleted.2005 Day122hour800appearedidenticallytwice.Onewasdeleted,Day124hours600to800were
filledinwithdatafromSunbrook2006 Day67hour1600minimumtemperaturewasmissingthevaluefrom1700wasused.Hour1500
alldatawasmissingtheaveragesofvaluesfor1400andcorrectecd1600wereused.Dailyvalues(exceptmaximumairtemperature)weretakenasaveragesofdays66and69.Day93hour12wastakenasanaverageofhours1100and1300.
2008 Day70,hour700wasmissing(daylightsavingsshift)anaverageofhours600and800wasusedtocreatea700dataset.
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SpanishFork2002 Day61hour2100valuesweretakenasanaverageof2000and2200.Day16hour1000average
airtemperatureandrelativehumidityaswellasminimumairtemperatureweretakenasaveragesfrom800,900,1100,and1200.Day29hour1500averageairtemperatureandrelativehumidityaswellasminimumairtemperatureweretakenasaveragesfrom1300,1400,1600,and1700.Day122,hour1600valuesweretakenasanaverageof1500and1700.Day67hour200valuesweretakenasanaverageof100and300.Day136hour700valuesweretakenasanaverageof600and800.Day172,hour200valuesweretakenasanaverageof100and300.Day152,hour1500averageairtemperatureandrelativehumidityaswellasminimumairtemperatureweretakenasaveragesfrom1400and1600.Day189,hour1400wasrepeatedwithdifferentdatathesecondwasdeleted.Day207,hour200valuesweretakenasanaverageof100and300.Day223,hour200valuesweretakenasanaverageof100and300.Day241hour200valuesweretakenasanaverageof100and300.Day252hour1300wasrepeatedwithdifferentdata.Thesecondwasdeleted.
2003 Dailycalculationsonlyweredonefordays1–30.Fordays114to365,datawassavedeverytwohours,windwassavedasmph,thiswasmultipliedbytwotogetwindrunfor2hours.Day36dailyvaluesweretakenasanaverageofdays35and37,exceptmaximumrelativehumidity.Day113minimumdailyairtemperaturewastakenasanaverageofdays112and114.
2004 Alldatawassavedevery2hours.Windwassavedasmphandmultipliedby2togetwindrunfor2hours.
2005 DatauptoDay124wassavedevery2hours,windwassavedasmphandmultipliedby2togetwindrunfor2hours.Day31,hour1600toDay34weremissingaveragesfromdays28‐30and35‐37wereusedtofillinthedailygap.Day124minimumdailyairtemperatureandhumidityaswellassolarradiationandsoiltemperaturevalesweretakenasanaveragefromdays123and135.
2006 Replicadatabetweendays137and179wasdeleted.Sunbrook2002 Day98hour1200wastakenasanaverageofhours1100and1300.2003 Day28alldailyvaluesexceptmaximumairtemperatureandwind,weretakenasaveragesfrom
days27and29.Days175to179wereduplicated,aswereday189hour300today194hour1300,theduplicatesweredeleted.
2004 Day336minimumairtemperatureandrelativehumidityvaluesweretakenasaveragesofdays335and337.Day306hour600appearstwicewithdifferentdatathesecondlinewasdeleted.Day307hour600appearstwicewithdifferentdata.Thesecondlinewasdeleted.
2005 Somehourlyvaluesweren’tsavedfromdays1to28,dailycalculationsonly,weredoneforthisperiod.Day336hour900wasmissingminimumairtemperature,thevaluefrom800,wasused.Day76hour600appearstwicewithdifferentdata.Thesecondlinewasdeleted.
2006 Temperaturedatafromday252athour200today256athour1200andday257athour1200haderrors,thisdatawasreplacedwithdatafromSouthgate.
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APPENDIXF:AdjustmentsMadetoIndividualLysimeterDrainageValuesDuetoOvertopping
LoganThenew(East)lysimeterwasinstalledin2004withdatacollectionbeginninginearlyMay(Table9).Drainageadjustmentsweremadetothe2004and2005data.AtLoganthemaximumvolumethedrainagebucketscouldholdwasequivalentto0.81inchesofwaterappliedovertheareaofthelysimeter.OvertoppingeventsoccurredonSeptember3,2004,March28,2005,April28,2005,drainagefortheseeventswasadjustedto1.25,1.54,and1.74inches,respectively.AnovertoppingeventalsooccurredonJune10,2005,butthemodelshowedthatnochangewasnecessarysoitwasleftat0.81inches.DrainageadjustmentsfortheEastlysimeterweremadeforeveryyearexcept2004(Table10).Thedatesoftheovertoppingeventsandadjustmentsforthislysimeterin2002were:April30wasadjustedto1.00,June24to0.91,andSeptember,8to1.58.OnSeptember2,2003,anovertopeventwasestimatedtobe0.99inches,thiswasfoundbythemodeltobeanoverestimatesothedrainagewasadjustedto0.82inches.For2005anovertopeventonMarch25wasadjustedto1.65inches.Twoovertopeventswererecordedin2006,onJuly1andSeptember15.ThedrainageonJuly1wasnotadjusted,theother,however,wasadjustedto2.01inches.In2007twoadjustmentsweremade,oneonJune7to1.48inchesandoneonJuly26to1.06inches.AneventonJuly2,2007wasnotadjusted.AdjustmentsweremadeforallyearsfortheWestlysimeter(Table11).Inboth2002and2003theadjusteddrainagevaluesarelowerthanthereportedvaluesbecausebothyearshadlargenumbersofovertopevents,sevenin2002and5in2003.Inbothyearsfourvaluesdidnotneedadjusting,buthadbeenoverestimatedwhentheywereinitiallyrecorded.Thesevalueswerealladjustedto0.82inches.ThishappenedonJune7,14,and17andJuly15,2002,aswellasApril21,June14,August18and22,2003.Other2002overtopeventsoccurredApril30,June4,andSeptember8.Theseeventswereadjustedto1.58,0.92,and1.01inches,respectively.Oneeventwasadjustedin2003,onSeptember29.Itwaschangedto0.95inches.Twoovertopeventswereadjustedin2004,onMay13,adjustedto1.10inches,andSeptember3,adjustedto1.44inches.AneventonJuly16,2004wasnotadjusted.For2005,fiveeventswerenotadjusted,theyoccurredonJuly15and18,August29,andSeptember2and9.EventsonMarch28andApril28werechangedto1.69and1.95inches,respectively.DrainagevaluesforSeptember15andOctober8,2006wereadjustedto2.06and1.24inches.Fiveothereventsin2005on:May24and30,July25,August17,andSeptember20,werenotadjusted.Fourovertopeventsoccurredin2007,ofwhichtwowereadjusted.EventsonJune7andOctober9werechangedto1.53and1.16inches.TheothertwoeventsoccurredonJuly2and30.MurrayBecauseofdeficitirrigation,veryfewdrainageeventsoccurredforeachcalculationperiodatMurray;thusanyabnormaldrainagehadasignificanteffectonthecalculatedcropcoefficient.Thiswasthecasein2005,thereforeKcvaluesforthisyearareconsiderablyhigherthanvaluescalculatedforotheryears.
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Forbothlysimetersnodrainageadjustmentswereneededfortheyears2003through2005.However,adrainagebucketovertopeventoccurredonbothlysimetersonNovember4,2004.Theseeventswerenotadjustedandwereleftat0.97,theequivalentdepthoverthelysimetercorrespondingtothemaximumvolumewhichthedrainagebucketscouldhold.FortheEastlysimeter(Table12)adjustmentsweremadeforJun21,2007,changedto4.47inches,andJuly5,2007,changedto2.59inches.ThreeadjustmentsweremadetodrainagevaluesfortheWestlysimeteratMurray(Table13).ThefirstwasonJune21,2006,whichwasadjustedto1.31inches.AsecondoccurredonJuly5,2007,andwasadjustedto1.10inches.Thethirdevent,onJuly9,2007,mayhavebeenamissingdatavalue.Adrainagevalueof0.53incheswasaddedforthatdate.Southgate
DrainageadjustmentsweremadeeachyearforbothlysimetersatSouthgate(Tables14and15),withtheexceptionofEastlysimeterin2006.In2004overtopeventsoccurredtwiceattheEastlysimeter.OneoccurredonJune26,thiswasadjustedto1.04inches.TheothereventoccurredonOctober29;itwasnotadjustedbutwasleftat0.97,theequivalentdepthcorrespondingtoafulldrainagebucket.Twoovertopeventsoccurredin2005(September27andOctober24).Thefirstwasnotadjusted,butthesecondwaschangedto1.82inches.Duringthissameyearthemodelshowedsignificantdrainageonthreedays,forwhichtherecordshowednodrainage.Becausethereweresomeerrorsindatacollectiontheseanomaliesweretreatedasovertopevents.TheyoccurredonMay5,July21,andSeptember22;drainagevaluesof3.27,5.26,and3.74inches,respectively,wereuseddays.In2007fourovertopeventsoccurred,noadjustmentsweremadethefirsttwo,onJuly6andAugust29.TheothertwoeventswereonSeptember22,changedto1.45inches,andDecember2,changedto1.52inches.FortheWestlysimeteranovertopeventoccurredJune26,2004,on.Thedataforthiseventwasnotadjusted.AnovertopeventwasrecordedonOctober24,2005;thiswaschangedto2.25inches.In2005theWestlysimeterhadanomaliessimilartothosedescribedfortheEastlysimeter.TheyalsooccurredonMay5,June2,andJuly21.ThedrainageabnormalitiesinMayandJulywereadjustedto3.36and4.14inches,respectively.TheanomalyinJunewasnotadjusted.SpanishFork
NoovertopeventswererecordedforeitherlysimeteratSpanishForkforanyyear.Sunbrook
Adjustmentswereonlymadefor2005(SeeTables18and19).FortheEastlysimeterovertopeventsoccurredonFebruary28,August8,andSeptember18,2005.TheeventonFebruary28wasadjustedto4.19inchesandthatonSeptember18to1.07inches.TheeventinAugustwasnotchanged.Abnormalitieswerepresentinthe2005drainagerecordssimilartothosepresentatSouthgateforthesameyear.Theseoccasionswerealsotreatedasovertopeventsandwereadjustedaccordingly.TheadjustmentsweremadeonMay5,to1.93inches,andJuly21,to2.40inches.Twoovertopeventsoccurredin2005ontheWestlysimeter,oneonFebruary28andanotheronAugust8.Neithereventwasadjusted.TheabnormalitiesonMay5,andJuly21,werepresent,however,andvaluesof1.21and2.39incheswereinsertedforthesetimes.