基于MODIS时序数据的青海湖流域植被时空变化特征及其与气候因子的关系英文.docx

J. Geogr. Sci. 2014, 24(6):1009-1021DOI:10.1007/s11442-014-1134-y? 2014 Science Press Springer-VerlagSpatial-temporal patterns of vegetationdynamicsand their relationships to climate variationsinQinghai Lake Basin using MODIS time-seriesdataGUO Wei1, NI Xiangnan1, JING Duanyang1, *LIShuheng2School of Human Settlements and Civil Engineering, Xian Jiaotong University, Xi’an 710049,China;School of Urban and Resources Sciences, Northwest University, Xi’an 710032,ChinaAbstract:Globalwarminghasledtosignificantvegetationchangesinrecentyears.Itisnecessarytoinvestigatetheeffectsofclimaticvariations(temperatureandprecipitation)onvegetationchangesforabetterunderstandingofacclimationtoclimaticchange.Inthispaper,wefocusedontheintegrationandapplicationofmulti-methodsandspatialanalysistech-niques inGISto study thespatio-temporal variationof vegetation dynamicsand toexplore thevegetationchangemechanism.ThecorrelationsbetweenEVIandclimatefactorsatdifferenttimescaleswerecalculatedforeachpixelincludingmonthly,seasonalandannualscalesrespectivelyinQinghaiLakeBasinfromtheyearof2001to2012.Theprimaryobjectivesofthisstudyaretorevealwhen,whereandwhythevegetationchangesoastosupportbetterunderstandingofterrestrialresponsetoglobalchangeaswellastheusefulinformationandtechniquesforwiseregionalecosystemmanagementpractices.Themainconclusionsareasfollows:(1)OverallvegetationEVIintheregionincreased6%duringrecent12years.TheEVIvalueingrowingseasons(i.e.springandsummer)exhibitedverysignificantimprovingtrend,accountedfor12.8%and9.3%respectively.ThespatialpatternofEVIshowedobviousspatialheterogeneitywhichwasconsistentwithhydrothermalcondition.Ingeneral,theveg-etation coverage improved in most parts of the area since nearly 78% pixel of the wholebasinshowed increasing trend, while degraded slightly in a small part of the area only. (2) TheEVIchange was positively correlated with average temperature and precipitation.Generallyspeaking,inQinghaiLakeBasin,precipitationwasthedominantdrivingfactorforvegetat