学科分类
/ 8
155 个结果
  • 简介:Theproductionofwood-basedpanelwaspresentedfirstlyinthispaper.SomefeaturesofChina’swood-basedpanelindustrywerereviewed,includingproductionbases,rawmaterialsandmainmarketsofwood-basedpanel.Inaddition,thetradeflowofwood-basedpanelwasdescribedintheend.

  • 标签:
  • 简介:Light-weightcompositepanelsweremanufacturedusingkenafcoreparticlesascorematerialandkenafbastfiber-wovensheetsastopandbottomsurfaces.Methylenediphenyldiisocyanate(MDI)resinwasusedastheadhesivewiththeresincontentof4%forcoreparticlesand50g/m2forbastfiber-wovensheets.Thetargetboarddensitiesweresetat0.35,0.45and0.55g/cm3.ThecompositepanelswereevaluatedwithJapaneseIndustrialStandardforParticleboards(JISA5908-2003).Theresultsshowthatthecompositepanelhashighmodulusofruptureandinternalbondingstrength.Thepropertiesof0.45g/cm3densitycompositepanelare:MOR20.4MPa,MOE1.94MPa,IB0.36MPa,WA142%,TS21%.Kenafisagoodrawmaterialformakinglight-weightcompositepanels.

  • 标签: 洋麻 木心材料 树皮纤维 复合板
  • 简介:Inthispaper,thephysicalandmechanicalpropertiesoflaminatedbamboolamberwerestudiedbytestingmoisturecontent,delaminationratio,horizontalshearstrength,MOEandMORofthestructure-usematerial,inthesametime,thesesubjectsoffinger-jointweretestedtoo.Theresultsshowedthat,thehorizontalshearstrength,MOR,MOEoflaminatedbambooweresuperiortotheordinarystructure-usetimberinarchitecture,suchasPinus.Theperformanceofagingtestwasnotextraordinary,althoughthephysicalandmechanicalpropertiesoflaminatedbamboolamberdecreasedafteragingtest,thesepropertieswerebeyondPinusyet.

  • 标签: 竹材层压人造板 物理性能 机械性能 建筑材料
  • 简介:Themanufacturetechnologiesoftwokindsofbamboolaminatedpanelandtheirphysical-mechanicalpropertieshavebeenstudiedinthepaper.ThespeciesofbambooaretheD.yunnanicusHsuehetD.Z.LiinYunnanProvinceandP.heterocyclavar.pubescensOhwiinZhejiangProvince.Thedataareofferedinordertoprovideprooftoproducearchitecturalpanelbybamboomaterials.Theresultsshowasfollows:Laminatedbamboopanelcanbeproducedbythereconstructiontechnology,andthemechanicalprope...

  • 标签:
  • 简介:ThefeasibilityofERSSARTandemdataformappingforestandnon-forestcoverinChinawasevaluatedoverZengchengCountyintheSouthChina.Anaccuracyof75%hasbeenachieved.Then,theMACFERST(MappingChinaForestwithERSSARTandemdata)projectstartedbytheMinistryofScienceandTechnology(MOST)ofChinaandtheEuropeanSpaceAgency(ESA)in1999.Thegenerationofalarge-scaleforestmaprequiressolvingproblemssuchasthegeoreferencingandmosaickingofverylongimagestripscov...

  • 标签:
  • 简介:ThepurposeofthispaperistostudytheRSdatawebservicesandrelatedsubjectsofdatastorageanddatamanagement.Basedonananalysisofthepresentsituationanddevelopmenttrendofstorageandmanagementofrasterdataandwebservicetechnology,amanagementandservicesystemarchitectureforRemoteSensingrasterdatabasedonwebservicetechnologieswasdeveloped,theimplementationmethodologiesofthekeytechnologyofthesystemwereexploredandaprototypeofthesystemwasillustrated.

  • 标签: 遥感技术 光栅数据 管理系统 网络技术 服务器
  • 简介:Basedonsixthandseventhnationalforestryinventorydataofthesixprovinces,includingGuangdong,Jiangxi,Guizhou,Shaanxi,JilinandBeijing,thethreemethods(IPCC,continuousfunctionforbiomassexpansionfactorandweightedbiomassregressionmodel)wereselectedtoestimatewoodbiomassinthispaper.Theestimationofthethreemethodswerecomparedandanalyzedfromcalculatingprocess,methodcharacters,repeatabilityandverifiabilitytostabilityofgrowthrateofbiomassbetweentwoperiods.TheresultsshowedthetotalbiomassestimatedbyIPCCmethodwithvariableBEF2waslarge,thetotalbiomassestimatedbyIPCCmethodwithconstantBEF2wassmallandthetotalbiomassesestimatedbycontinuousfunctionforbiomassexpansionfactorandweightedbiomassregressionmodelweremiddle.Thebiomassexpansionfactorderivedfromweightedregressionmodelwasmoststableinthedifferentprovinces.Basedontheseventhnationalforestryinventorydata,thebiomassexpansionfactorsofvariouskindsoftreespeciesderivedfromIPCCandtheweightedregressionmodelweremorestablethanthebiomassexpansionfactorsderivedfromcontinuousfunctionmethod.Thegrowthrateofbiomassbetweentwoperiodswasthesameregularpatternasthebiomassexpansionfactors.

  • 标签: IPCC continuous function for BEF(biomass EXPANSION
  • 简介:Climateisadominantenvironmentalfactorinbuildingecosystemstructureanddrivingbioticdynamicswithtopographicdependenceonspatialdistribution.Thispaperdemonstratestheapplicationofinterpolationtechniquetodescribespatialclimatedistribution.Adigitalelevationmodel(DEM)inresolutionof0.01degreeoflatitudeandlongitudehasbeendevelopedbecausetheincorporationofspatialdependenceontopographyiscrucialtoaccuracyofinterpolation.Climatedatafromsparseanddiscr...

  • 标签:
  • 简介:目前,关于防风林的保护的效果的大多数研究根据森林带和网络的二规模。与关于全球环境变化的进一步的研究,然而,更多的注意对防风林的地区性的气候效果被给予。在现在的学习,我们由使用陆地表面温度(LST)在地区性的规模分析了防风林的温度效果从在在到在2008的10月的从三月的中国的吉林省的Yushu,Nongan,Dehui,和Fuyu的中等决定成像分光辐射函数(MODIS)的数据。结果证明防风林能作为与没有防风林地区相比增加保护的农田的土壤温度,与0.57的增长吗?

  • 标签: MODIS数据 防护林带 土壤温度 区域尺度 中分辨率成像光谱仪 评估
  • 简介:Forestgrowthismainlycurrentlymonitoredusingin-situmeasurementsinnortheastofChina.Toeffectivelymonitorforestgrowthdisturbanceatlargescale,weattemptedtouseremotesensingtechnique,particularly,timeseriesMODISdatafrom2004to2006.Theannualtimeseriesof8-dayenhancedvegetationindex(EVI)datasetwasgeneratedandsmoothedusingaSavitzky-Golayfilter.TheEVItrajectoryduringgrowthseasonwassimulatedusingalogisticmodel.Fromthesimulatedtrajectory,theEVIareaofgrowthseasonandannualEVIentropywerecalculated.Thesetwofactorswerecombinedtomapthedisturbanceregionsofforestgrowth.Finally,thedisturbanceregionswereverifiedusingasetofrandomsamples.Theresultindicatesthatthedisturbancepointshavedistinctivelyhigherentropyandlowerpeak.SomeofthesepointsalsoshowabruptEVIdeclineduringthemidseasonofthepeakphasesordoublepeaks.Thisapproachisdemonstratedtobefeasiblefordisturbancemonitoringofforestgrowth.

  • 标签: time series MODIS EVI growth SEASON
  • 简介:农业庄稼的大规模耕作为领域害虫管理要求疾病的即时察觉。Hyperspectral遥感数据通常高光谱分辨率,它能为在叶和华盖在绿植被检测疾病应力很有用铺平。在这研究,在实验室和领域的大米的hyperspectral反射被测量描绘光谱区域和wavebands,它对棕色的点由Bipolarisoryzae感染了的大米最敏感(HelminthosporiumoryzaeBreda。deHann)。叶反射与感染的叶表面的增加的百分比在450~500nm和630~680nm的范围增加了,并且在520~580nm的范围减少了,760~790nm,1550~1750nm,并且有感染的叶表面的增加的百分比的2080~2350nm分别地。敏感分析和衍生物技术被用来为棕色的点由B感染了的米饭的察觉选择敏感wavebands。oryzae。米饭叶反射的比率作为棕色的点的指示物被评估。R669/R746(在669nm的反射在746nm由反射划分了,下列比率可以被类比推出),R702/R718,R692/R530,R692/R732,R535/R746,R521/R718,并且R569/R718作为棕色的点不管它是否在叶或华盖水平有增加了的米饭的发生显著地增加了。R702/R718,R692/R530,R692/R732是为估计米饭褐的疾病严厉的三比率在叶和华盖层次看到的最好。这结果不仅在在真实世界上为精确害虫管理描绘庄稼疾病证实hyperspectral遥感数据的能力,而且证明庄稼反射的比率是一个有用方法估计庄稼疾病严厉。

  • 标签: 导数光谱 水稻 褐斑病 疾病预防
  • 简介:Informationaboutthespatialdistributionofsoilattributesisindispensableformanylandresourcemanagementapplications;however,theabilityofsoilmapstosupplysuchinformationformodernmodelingtoolsisquestionable.Theobjectivesofthisstudyweretoinvestigatethepossibilityofpredictingsoildepthusingsometerrainattributesderivedfromdigitalelevationmodels(DEMs)withgeographicinformationsystems(GIS)andtosuggestanapproachtopredictothersoilattributes.Soildepthwasdeterminedat652fieldobservationsovertheAl-MuwaqqarWatershed(70km2)inJordan.Terrainattributesderivedfrom30-mresolutionDEMswereutilizedtopredictsoildepth.Theresultsindicatedthattheuseofmultiplelinearregressionmodelswithinsmallwatershedsubdivisionsenabledthepredictionofsoildepthwithadifferenceof50cmfor77%ofthefieldobservations.Thespatialdistributionofthepredictedsoildepthwasvisuallycoincidedandhadgoodcorrelationswiththespatialdistributionoftheclassesamalgamatingthreeterrainattributes,slopesteepness,slopeshape,andcompoundtopographicindex.Thesesuggestedthatthemodelingofsoil-landscaperelationshipswithinsmallwatershedsubdivisionsusingthethreeterrainattributeswasapromisingapproachtopredictothersoilattributes.

  • 标签: 土壤深度 数据预测 数字地形 视觉 多元线性回归模型 属性空间
  • 简介:Keerqin沙土地位于在向东北平凡、内部的蒙古之间的过渡地面(42°41′-45°15′N,118°35′-123°30′E)在东北Chinaand,它被沙漠化严重影响。根据地球表面的配置和生态环境,植被,赤裸的砂土的职业比率和土壤质地的范围被使用地调查数据作为评估索引选择。Keerqin沙的沙漠化的评估索引系统被使用遥感数据建立,并且赤裸的砂土的职业比率被混合光谱模型获得。这个索引系统被域调查数据验证,结果显示它对Keerqin的thedesertification评估合适。

  • 标签: 含沙土壤 遥感技术 荒漠化 生态环境 水土流失
  • 简介:MODIS(中等决定成像分光辐射函数)是在地(曙光女神AM)和水(曙光女神下午)上的一台关键仪器卫星。线性光谱混合模型为陆地封面的亚象素分类被用于MOIDS数据。在中国的浙江省的Shaoxing县被选择是学习地点,早米饭作为学习庄稼被选择。从MODIS象素使用的陆地封面的导出的比例线性光谱混合模型与从在一样的天获得的TM数据导出的无指导的分类相比,它暗示MODIS数据能为米饭耕作被用作卫星数据来源区域评价,可能米饭生长在地区性的规模上监视并且产量预报。

  • 标签: 水稻 种植区域 线性光谱混合剂 中等分变成像分光辐射度计
  • 简介:作为由地面生产的数据的数量,为根渗透雷达(GPR)大,传播和数据的存储消费大资源。减轻这个问题,我们这里用混乱粒子群建议一个根成像算法最佳(CPSO)压缩了根据根空间的稀少基于GPR数据察觉到。雷达数据以稀少的方式被分解,观察,测量并且代表,因此根图象能与有限数据被重建。第一,雷达信号测量和稀少的表示被实现,并且解决方案空格被小浪基础和高斯随机矩阵建立;第二,匹配的功能被看作健康功能,并且最好的健康价值被一个PSO算法发现;然后,混乱搜索被用来获得全球最佳的操作员;最后,根图象被最佳的操作符重建。分别地,从美国GSSIGPR的A扫描数据,B扫描数据,和复杂数据在试验性的测试被使用。为B扫描数据,计算时间被减少60?%和PSNR被改进5.539?dB;为实际的根数据成像,重建PSNR是26.300?dB,和全部的计算时间仅仅是67.210?s。CPSO-OMP算法克服本地最佳套住的问题并且包括地在重建期间提高精确。

  • 标签: 雷达数据 探地雷达 影像压缩 数据成像 传感 粒子群优化算法
  • 简介:WemappedtheforestcoverofKhadimnagarNationalPark(KNP)ofSylhetForestDivisionandestimatedforestchangeoveraperiodof22years(1988-2010)usingLandsatTMimagesandotherGISdata.SupervisedclassificationandNormalizedDifferenceVegetationIndex(NDVI)imageclassificationapproacheswereappliedtotheimagestoproducethreecoverclasses,viz.denseforest,mediumdenseforest,andbareland.Thechangemapwasproducedbydifferencingclassifiedimageriesof1988and2010asbeforeimageandafterimage,respectively,inERDASIMAGINE.Errormatrixandkappastatisticswereusedtoassesstheaccuracyoftheproducedmaps.Overallmapaccuraciesresultingfromsupervisedclassificationof1988and2010imagerieswere84.6%(Kappa0.75)and87.5%(Kappa0.80),respectively.Forestcoverstatisticsresultingfromsupervisedclassificationshowedthatdenseforestandbarelanddeclinedfrom526ha(67%)to417ha(59%)and105ha(13%)to8ha(1%),respectively,whereasmediumdenseforestincreasedfrom155ha(20%)to317ha(40%).ForestcoverchangestatisticsderivedfromNDVIclassificationshowedthatdenseforestdeclinedfrom525ha(67%)to421ha(54%)whilemediumdenseforestincreasedfrom253ha(32%)to356ha(45%).BothsupervisedandNDVIclassificationapproachesshowedsimilartrendsofforestchange,i.e.decreaseofdenseforestandincreaseofmediumdenseforest,whichindicatesdenseforesthasbeenconvertedtomediumdenseforest.Areaofbarelandwasunchanged.Illicitfelling,encroachment,andsettlementnearforestscausedthedenseforestdeclinewhileshortandlongrotationplantationsraisedinvariousyearscausedtheincreaseinareaofmediumdenseforest.ProtectivemeasuresshouldbeundertakentocheckfurtherdegradationofforestatKNP.

  • 标签: 遥感和地理信息系统 森林覆盖率 LANDSAT TM遥感影像 国家公园 覆被变化
  • 简介:Usingthemulti-temporalLandsatdataandsurveydataofnationalresources,theauthorsstudiedthedynamicsofcultivatedlandandlandcoverchangesoftypicalecologicalregionsinChina.TheresultsofinvestigationshowedthatthewholedistributionofthecultivatedlandshiftedtoNortheastandNorthwestChina,andasaresult,theecologicalqualityofcultivatedlanddroppeddown.TheseacoastandcultivatedlandintheareaofYellowRiverMouthexpandedbyanincreasingrateof0.73km?a-1,withadepositingrateof2.1km?a-1.ThedesertificationareaofthedynamicofHorqinSandyLandincreasedfrom60.02%ofthetotallandareain1970sto64.82%in1980sbutdecreasedto54.90%inearly1990s.AstothechangeofNorthTibetlakes,thewaterareaoftheNamuLakedecreasedby38.58km2fromyear1970to1988,withadecreasingrateof2.14km2?a-1.

  • 标签: 遥感信息 耕地 土地覆盖变化 典型生态区 中国
  • 简介:Background:Overthelastdecades,manyforestsimulatorshavebeendevelopedfortheforestsofindividualEuropeancountries.Theunderlyinggrowthmodelsareusuallybasedonnationaldatasetsofvaryingsize,obtainedfromNationalForestInventoriesorfromlong-termresearchplots.Manyofthesemodelsincludecountry-andlocation-specificpredictors,suchassitequalityindicesthatmayaggregateclimate,soilpropertiesandtopographyeffects.Consequently,itisnotsensibletocomparesuchmodelsamongcountries,anditisoftenimpossibletoapplymodelsoutsidetheregionorcountrytheyweredevelopedfor.However,thereisaclearneedformoregenericallyapplicablebutstilllocallyaccurateandclimatesensitivesimulatorsattheEuropeanscale,whichrequiresthedevelopmentofmodelsthatareapplicableacrosstheEuropeancontinent.ThepurposeofthisstudyistodeveloptreediameterincrementmodelsthatareapplicableattheEuropeanscale,butstilllocallyaccurate.Wecompiledandusedadatasetofdiameterincrementobservationsofover2.3milliontreesfrom10NationalForestInventoriesinEuropeandasetof99potentialexplanatoryvariablescoveringforeststructure,weather,climate,soilandnutrientdeposition.Results:Diameterincrementmodelsarepresentedfor20species/speciesgroups.Selectionofexplanatoryvariableswasdoneusingacombinationofforwardandbackwardselectionmethods.Theexplainedvariancerangedfrom10%to53%dependingonthespecies.Variablesrelatedtoforeststructure(basalareaofthestandandrelativesizeofthetree)contributedmosttotheexplainedvariance,butenvironmentalvariableswereimportanttoaccountforspatialpatterns.Thetypeofenvironmentalvariablesincludeddifferedgreatlyamongspecies.Conclusions:ThepresenteddiameterincrementmodelsarethefirstoftheirkindthatareapplicableattheEuropeanscale.Thisisanimportantsteptowardsthedevelopmentofanewgenerationofforestdevelopmentsimulatorsthatcan

  • 标签: EUROPEAN FORESTS Diameter INCREMENT model Climate
  • 简介:Forestsareamongthemostimportantcarbonsinksonearth.However,theircomplexstructureandvastareasprecludeaccurateestimationofforestcarbonstocks.Datasetsfromforestmonitoringusingadvancedsatelliteimageryarenowusedininternationalpolicyagreements.DatasetsenabletrackingofemissionsofCO2intotheatmospherecausedbydeforestationandothertypesofland-usechanges.TheaimofthisstudyistodeterminethecapabilityofSPOT-HRGSatellitedatatoestimateabovegroundcarbonstockinadistrictofDarabkolaresearchandtrainingforest,Iran.Preprocessingtoeliminateorreducegeometricerrorandatmosphericerrorwereperformedontheimages.Usingclustersampling,165sampleplotsweretaken.Of165plots,81wereinnaturalhabitats,and84wereinforestplantations.Followingthecollectionofgrounddata,biomassandcarbonstockswerequantifiedforthesampleplotsonaperhectarebasis.Nonparametricregressionmodelssuchassupportvectorregressionwereusedformodelingpurposeswithdifferentkernelsincludinglinear,sigmoid,polynomial,andradialbasisfunction.Theresultsshowedthatathird-degreepolynomialwasthebestmodelfortheentirestudiedareashavinganrootmeansquareerror,biasandaccuracy,respectively,of38.41,5.31,and62.2;42.77,16.58,and57.3%forthebestpolynomialfornaturalforest;and44.71,2.31,and64.3%forafforestation.Overall,theseresultsindicatethatSPOTHRGsatellitedataandsupportvectormachinesareusefulforestimatingabovegroundcarbonstock.

  • 标签: ABOVEGROUND carbon STOCK Support VECTOR machine
  • 简介:Background:Remotesensing-basedmappingofforestEcosystemService(ES)indicatorshasbecomeincreasinglypopular.TheresultingmapsmayenabletospatiallyassesstheprovisioningpotentialofESsandprioritizethelanduseinsubsequentdecisionanalyses.However,themappingisoftenbasedonreadilyavailabledata,suchaslandcovermapsandotherpubliclyavailabledatabases,andignoringtherelateduncertainties.Methods:Thisstudytestedthepotentialtoimprovetherobustnessofthedecisionsbymeansoflocalmodelfittinganduncertaintyanalysis.Thequalityofforestlanduseprioritizationwasevaluatedundertwodifferentdecisionsupportmodels:eitherusingthedevelopedmodelsdeterministicallyorincorporationwiththeuncertaintiesofthemodels.Results:PredictionmodelsbasedonAirborneLaserScanning(ALS)dataexplainedthevariationinproxiesofthesuitabilityofforestplotsformaintainingbiodiversity,producingtimber,storingcarbon,orprovidingrecreationaluses(berrypickingandvisualamenity)withRMSEsof15%–30%,dependingontheES.TheRMSEsoftheALS-basedpredictionswere47%–97%ofthosederivedfromforestresourcemapswithasimilarresolution.Duetoapplyingasimilarfieldcalibrationsteponbothofthedatasources,thedifferencecanbeattributedtothebetterabilityofALStoexplainthevariationintheESproxies.Conclusions:Despitethedifferentaccuracies,proxyvaluespredictedbyboththedatasourcescouldbeusedforapixel-basedprioritizationoflanduseataresolutionof250m~2,i.e.,inaconsiderablymoredetailedscalethanrequiredbycurrentoperationalforestmanagement.TheuncertaintyanalysisindicatedthatmapsoftheESprovisioningpotentialshouldbepreparedseparatelybasedonexpectedandextremeoutcomesoftheESproxymodelstofullydescribetheproductionpossibilitiesofthelandscapeundertheuncertaintiesinthemodels.

  • 标签: FORESTRY decision making Spatial PRIORITIZATION Light