稻田甲烷排放模型研究

2411200411ACTAECOLOGICASINICAVol.24,No.11Nov.,20041,2,1,23,2,2,2(11,210095;21,100029):(KZCX12SW201213);(G1999011805):2004203212;:2004208220:(1968),,,,GIS:Authorforcorrespondence.E2mail:[e-mail]:theKnowledgeInnovationProgramofChineseAcademyofSciences(No.KZCX12SW201213),theNationalKeyBasicRe2searchDevelopmentFoundationofChina(No.G1999011805)Receiveddate:2004203212;Accepteddate:2004208220Biography:ZHANGWen,Ph.D.,mainlyengagedinGISapplicationandglobalchange.:,,,,,,(CH4MOD),,:CH4MOD;;;Modelingmethaneemissionfromricepaddies:modelandmodificationZHANGWen1,2,HUANGYao1,23,ZHENGXun2Hua2,LIJing2,YUYong2Qiang2(11CollegeofResourcesandEnvironmentalSciences,NanjingAgriculturalUniversity,Nanjing210095,China;21InstituteofAtmosphericPhysics,ChineseAcademyofSci2ences,Beijing100029,China).ActaEcologicaSinica,2004,24(11):23472352.Abstract:PreciseestimatesofCH4emissionsfromricefieldshavebeendifficulttodetermineduetoregionaldifferencesinspa2tialandtemporalvariabilityinclimate,soilsandagriculturalpractices.Toobtainestimatesofmethaneemissionsfromregionalorglobalricepaddies,attentionmustbefocusedonanexaminationofmethodologiesbywhichthecurrenthighuncertaintiesintheestimatesmightbereduced.Onepossiblewaytodothisisthedevelopmentofpredictivemodels.Withanunderstandingoftheprocessesofmethaneproduction,oxidationandemission,Huangetal.developedamodeltopredictmethaneemissionfromricepaddysoils.ValidatedagainstindependentfieldmeasurementsofmethaneemissionfromricepaddiesinUSA,ChinaandI2taly,Huang’smodelprovidesarealisticestimateoftheobservedresults.However,Huang’smodelwasprimarilydevelopedforcontinuousfloodingandnotforintermittentirrigationricepaddies.Moreover,themethaneemissionviaebullitionwasnottak2enintoaccountintheirmodel.TheobjectiveofthispaperistomodifyHuang’smodelsoastomakeitcapableofsimulatingmethaneemissionsfromirrigatedricefieldsundervariousagriculturalpractices.Weacceptthehypothesisfromtheoriginalmodelthatmethanogenicsubstratesareprimarilyderivedfromriceplantsandaddedorganicmatter.Ratesofmethaneproductioninfloodedricesoilsaredeterminedbytheavailabilityofmethanogenicsub2stratesandtheinfluenceofenvironmentalfactors.Thefractionofmethaneemittedthroughplantsiscontrolledbyricegrowthanddevelopment.Ratesofmethanetransportedfromsoiltotheatmosphereviaplantsaredeterminedbytheratesofproduc2tionandtheemittedfraction.Modificationtotheoriginalmodelfocusesontheeffectofwaterregimeonmethaneproductionöemissionandthemethanetransportviabubbles.TheeffectofwaterregimewasquantifiedbysoilEh.ChangesofthesoilEh©1995-2005TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.duringdrainagecourseandre2floodingcourseweresimulatedbytwodifferentialequations,respectively.SimulationofthesoilEhduringthere2floodingcourseassociatedthedecompositionofaddedorganiccarbon.Methaneemissionviabubbleswasmod2eledbysoiltemperature,ricerootgrowthandthedifferencebetweenmethaneproductionrateandacriticalratewhenthebub2blesoccur.Newfeaturesofthepresentmodel,namedasCH4MOD,aretheincorporationofbubblefluxprocessandthedrainageeventsintotheoriginalmodel.Overall,theadvantagesofthismodelmakeitparticularlyapplicabletothesimulationofmethaneemissionsfromirrigatedricefieldswithfewinputparametersofirrigationpatterns,typeandamountoforganicmatteramendment,ricegrainyield,airtemperature,andsoilsandpercentage.Keywords:CH4MOD;ricepaddies;methane;model:100020933(2004)1122347206:Q958:A(CH4),20a,(GlobalWarmingPotential)CO262[1],9%30%[2,3],[4,5],(,),[68],,,,GIS,,,,[914],Huang[10],vercelliIPCC2000(GoodPracticeGuidanceandUncertaintyManagementinNationalGreenhouseGasInven2tories:IPCC,2000),Huang’s,,,[1517],[18],Huang’s,,,Huang’s,ö,Huang’s,1Huang’sHuang’s,(),111,:COM=0165SITI(k1OMN+k2OMS)(1),COM(gö(m2d))OMNOMS(göm2),k1k2SITI,:CR=11810-3VISIW1125(2),CR(gö(m2d)),VI,,W(göm2):843224©1995-2005TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.W=Wmax1+B0exp(-rt)(3)B0=WmaxöW0-1(4)Wmax=9146GY0176(5),GY(göm2),W0Wmax(göm2),t(d),r112(,SAND)(Tsoil)(Eh),:SI=01325+010225SAND(6)TI=QTsoil-31010(Tsoil=3030Tsoil40)(7)FEh=exp-117150+Eh150(Eh=-150Eh-150),24[5,19],Q10=310Eh(mv),[10]113,,(P,gö(m2d)):P=0127FEh(COM+TICR)(9),0127(CH4)(C6H12O6),(Fp)(10):Fp=01551-WWmax0125(10)(9)(10)(Ep,gö(m2d)):Ep=EpP(11)2Huang’sHuang’s[10],,,,211,,,,,[5,1922],(E,gö(m2d)):E=Ep+Ebl=minFp,1-EblPP+Ebl(12),P(gö(m2d)),Ebl(gö(m2d)):Ebl=017(P-P0)ln(Tsoil)öWroot(13),P0(gö(m2d))PP0,,P001002Tsoil()Wroot(göm2),Yoshida[23],,:Wroot=01136(Wroot+W)01936(14),W(göm2)(14),W((3)),(Wroot(0)=0943211:,1999,(),©1995-2005TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.,Wroot(i)-Wroot(i-1)011),212EhMishra,Eh;Eh[16]Eh,Matthews,Eh,[13],()Eh:Eh(t+1)=Eh(t)-DEh(AEh+min(1,COM))(Eh(t)-BEh)Eh(t+1)=Eh(t)-DEh(AEh+017)(Eh(t)-BEh)(15),t,Eh(t)tEh,AEhDEh[24]Eh,AEhDEh01230116BEhEh()(),300mv-250mvEh,,Eh300mv-250mv,Eh[18],,,Eh,Eh-20mv,1020mv3,,11Table1Descriptionofmodelinputparameters,variablesandempiricalconstantsItemDefinitionanddescriptionValueRicegrowthWAbovegroundmassVariable(göm2)W0Abovegroundmassattransplantingdate15(göm2)WmaxAbovegroundmassatharvestVariab