简介:Long-lastingexpansionofhazepollutioninChinahasalreadypresentedasternchallengetoregionaljointpreventionandcontrol.Thereisanurgentneedtoenlargeandreconstructthecoverageofjointpreventionandcontrolofairpollutioninkeyarea.Airqualitymodelscanidentifyandquantifytheregionalcontributionofhazepollutionanditskeycomponentswiththehelpofnumericalsimulation,butitisdifficulttobeappliedtolargerspatialscaleduetothecomplexityofmodelparameters.Thetimeseriesanalysiscanrecognizetheexistenceofspatialinteractionofhazepollutionbetweencities,butithasnotyetbeenusedtofurtheridentifythespatialsourcesofhazepollutioninlargescale.Usingeconometricframeworkoftimeseriesanalysis,thispaperdevelopedanewapproachtoperformspatialsourceapportionment.WeappliedthisapproachtocalculatethecontributionfromspatialsourcesofhazepollutioninChina,usingthemonitoringdataofparticulatematter(PM2.5)across161Chinesecities.Thisapproachovercamethelimitationofnumericalsimulationthatthemodelcomplexityincreasesatexcesswiththeexpansionofsamplerange,andcouldeffectivelydealwithseverelarge-scalehazeepisodes.
简介:Nepalisoneofthetopthreeexportersoflargercardamom(AmomumsubulatumRoxb.)intheworldmarketcontributinglargelytotheNepaleseeconomy.Sub-HimalayanrangeofhillyareaofeasternNepalispopularforlargecardamomcultivation.Beingsimilarphytogeographicalandecologicalsetting,cultivationhasbeguninhillsofKathmanduValleyhoweverlandsuitabilityneedstobeevaluatedwithreferencetospecificneedofthecrop.Kathmanduisavalleywithalluvialbottomandaltitudinalrangebetween1200and2730mabovesealevelhavingcooltowarmtemperateclimaticrange.Varietiesofaspectsandslopegradienthavepotentialityforthelargecardamomcultivation.Aimofthestudywassettocategorizeavailablelandareaintherangeofsuitabilityforlargecardamoncultivationonthebasisofphysicalcharacteristicsofthelandandecologicalneedofcrop.LandevaluationmethodologyhasbeendesignedalongwithsitespecificamendmentinFAOframework(1976).Landusemapinscaleof1:25000wasusedingeographicinformationsystemenvironment.Suitabilitywasdonethroughmapoverlayingmethods.Aimofthestudywassettocategorizeavailablelandareaintherangeofsuitabilitycategoriesforlargecardamomcultivationbasedonphysicalcharacteristicsofthelandmatchingwithecologicalneedofcrop.AnalysisofdatashowsthataltitudinalrangeatuplandsofKathmanduValleyandannualaveragerainfallandtemperaturearefoundtobewithinsuitabilityrangeforAmomumsubulatumcultivation.Sandyloamsoil,slightlyacidicinnaturewithgentleslopinglandofabout5-8°provideshighlysuitablecondition.Resultshowedthatmorethanone-thirdoftotallandareaabove1800mofaltitudeissuitable.Selectively,ofthetotalarea,5%arenorthfacingslope,13%gentleslopesarehighlysuitable.16%landswithnortheastorientationaremoderatelysuitable.Mostofthelandareaswhicharemarginalysuitabileforvegetableandcerealcropsarehighlysuitableforlargecardamom.Hillsofnorthernboundary
简介:WiththeeconomicdevelopmentandtheaccelerationofmotorizationinChina,thenumberofprivatecarsincreasesrapidlyinurbanareas.However,thelimitofurbanresourcesandthecontradictionbetweentrafficsupplyanddemandareincreasinglyprominentinlargecities,whileprivatecarconsumptionhasbeenanew'light'inmediumandsmallcities.Consumers’behaviorsdifferfromregiontoregion.Aimingattheaboveproblems,weformulatestructuralequationmodelingandcarryoutempiricalresearch.Inthispaper,acomparativestudyaboutthemaininfluentialfactorsthataffecttheconsumptionofprivatecarsinlargeandsmallcitiesinChinaismade,anditishopedthatsomeguidanceforpolicyrecommendationscanbeobtained.