植株冠层几何形状对草地反射率的影响

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1、Seediscussions,stats,andauthorprofilesforthispublicationat:https://www.researchgate.net/publication/301199119EffectsofcrownshapeonreflectanceofgrasslandArticleinJournalofRemoteSensing·January2007CITATIONSREADS4552authors,including:NaZhangChineseAcademyofSciences37PU

2、BLICATIONS222CITATIONSSEEPROFILESomeoftheauthorsofthispublicationarealsoworkingontheserelatedprojects:Eco-hydrologicaleffectsofurbanlandscapespatialpatternchangeandcoupledsimulationViewprojectAllcontentfollowingthispagewasuploadedbyNaZhangon11April2016.Theuserhasre

3、questedenhancementofthedownloadedfile.第11卷第1期遥感学报Vol.11,No.12007年1月JOURNALOFREMOTESENSINGJan.,2007文章编号:100724619(2007)0120009211植株冠层几何形状对草地反射率的影响张娜,赵英时(中国科学院研究生院资源与环境学院,北京100049)摘要:本研究建立了一个反映植被辐射传输和几何光学特性的混合模型,以模拟半干旱地区天然草地的多波段反射率值。该模型引入一个几何相似性参数,用以描述植株冠层的几何形状对叶/枝角分

4、布、阴影地面比例、冠层和地面各光学分量、冠层反射率和总反射率的影响。模型模拟值与研究区3个不同退化程度羊草草地的实测值较为吻合,而且退化程度越轻的草地,模拟效果也越好。对于中度退化草地,在高度与冠幅之比(chw)不变的情况下,当45°≤太阳天顶角sza≤75°时,不同几何形状植株的总反射率之间无显著差异;当0°≤sza<45°或75°

5、;几何相似性参数;植株冠层的几何形状;半干旱天然草地中图分类号:TP701文献标识码:AEffectsofPlantCrownShapeonReflectanceofGrasslandZHANGNa,ZHAOYing2shi(CollegeofResourcesandEnvironment,GraduateUniversityofChineseAcademyofSciences,Beijing100049,China)Abstract:Thestudyestablishedanintegratedmodelcombining

6、radiativetransferandgeometricopticalpropertiesinordertosimulatemulti2spectralreflectanceofsemi2aridnaturalgrassland.Themodelintroducedageometricalsimilarityparameter,whichdescribestheinfluencesofplantcrownshapeonleaf/branchangledistributionfrequencies,fractionofsha

7、dowedorilluminatedcanopyandbackground,canopyreflectance,andfinallyscenereflectance.ThesimulatedresultsagreedwiththemeasuredvaluesinthethreeLeymuschinensegrasslandswithdifferentdegradationdegree,andthelowerwasdegradationdegree,thebetterweresimulatedresults.Forthemod

8、eratelydegradedgrasslands,ifplantcrownheight2to2widthratio(chw)wasinvariant,when45°≤solarzenithangle(sza)≤75°,nosignificantdifferencesoccurredins