Page 27 - 2024年第55卷第5期
P. 27
High - resolutionmodelingofurbanwaterandcarbonfluxesin
themainurbanareaofBeijing ,China
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SHAOWeiwei,SHAORui ,NIGuangheng,WANGYicheng,YANGZhiyong,LIUJiahong
(1.StateKeyLaboratoryofSimulationandRegulationofWaterCycleinRiverBasin,ChinaInstituteof
WaterResourcesandHydropowerResearch,Beijing 100038,China;
2.StateKeyLaboratoryofHydroscienceandEngineering,Departmentof
HydraulicEngineering ,TsinghuaUniversity,Beijing 100084,China)
Abstract:Urbanizationaltershydrologicalandecologicalprocesses,suchasregionalwater - heatbalance,byaf
fectingsurfaceevapotranspiration (ET)processes,whichinturnchangesthestructureandfunctionofterrestriale
cosystems.Toscientificallyassesstheurbanwater - carbonprocess ,thisstudyestimatedthemonthlyvegetationin
dexat10m × 10mspatialresolutioninthemainurbanareaofBeijingfrom2016to2021basedonthevegetationin
formationfromSentinel - 2data ,andfurthercombinedwiththePT - JPLimmodel,theInVEST(IntegratedValua
tionofEcosystemServicesandTradeoffs),andtheanalyticalWUE(WaterUseEfficiency)modeltosimulatethe
monthly ET,ETpartitioning(transpirationE t ,soilevaporationE b ,interceptionevaporationE i ,andimpervious
surfaceevaporationE u ),grossprimaryproductivity(GPP),carbonstorage,andecosystemWUEforthemainur
banareaofBeijingataspatialresolutionof10m × 10m.Largervaluesofvegetationindexwereconcentratedinthe
westernmountainousareas,andtheparkareasofBeijingalsopresentedlargerNDVI(NormalizedDiffernceVegeta
tionIndex )withamaximumvalueof0.65.TheannualmeanETinthemainurbanareaofBeijingis497mm,with
thehighestETinthewesternmountainousarea,exceeding1000mm.ETincreaseswiththeincreaseofLAI(Leaf
AreaIndex )andEVI(EnhancedVegetationIndex).IncreasesinNDVI,LAI,andEVIwereobservedatarateof
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0.0048,0.016m ·m ,and0.0047peryear,respectively,from 2016to2021.TheregionalaverageE t was
141.51mm ,E i was50.77mm,andE b was272mm.E u wasdistributedonlyonimpervioussurfacesofbuilding
sites ,andE u ?ETonimpervioussurfaceswas18.2%.Theareaswithhighercarbonstorageweremainlydistributed
inthewesternmountains ,whichhadrelativelyhighelevation,highvegetationcover,andhighvaluesoftotalcar
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bonstoragedensityexceeding5t?hm .ThemeanvalueofGPPinthestudyareawas2.7g·m ·d ,andthe
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annualmeanWUEwas0.63g·mm .TherewasasignificantnegativecorrelationbetweenWUEandE t ?ET(R =
- 0.44 ,p<0.001),andWUEtendedtoincreasesignificantlywithincreasingGPP.Therefinedurbanwaterand
carbonsimulationcanprovideatheoreticalbasisfortheconstructionandevaluationofspongecities,andthesimu
lationofurbanwaterandcarbonfluxesisofgreatsignificancefortheachievementofthecarbonpeakingandcarbon
neutralitygoals.
Keywords:urbanization;ecosystems;evapotranspiration;Beijing;wateruseefficiency
(责任编辑:耿庆斋)
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