%0 Journal Article
%T The Variability of NDVI over Northwest China and Its Relation to Temperature and Precipitation<br>中国西北地区NDVI变化及其与温度和降水的关系
%A LI Zhen
%A YAN Fu-li
%A FAN Xiang-tao
%A <br>李震
%A 阎福礼
%A 范湘涛
%J 遥感学报
%D 2005
%I 
%X Land vegetation plays amajorrole inthe global climate change through carbon cycle,and climate change inturn af fects vegetation growth and its photosynthetic activity.In arid and semi-arid area,sparse vegetation cover characterizes environ ments.Thus quantitativetemporal series analysisofvegetation distribution and itsvariations enablesobservingannualtrends,helps to find out the reason for environment variability.There are serious environmental problems,such as deforestation,soil erosion, salinization,and desert encroachment in the northwestern China,its natural conditions is very delicate.In this paper,we built th time series of vegetation change by theNDVI(normalized difference vegetation index)covered northwest regions in recent 2 years,and analyzd the time serialNDVIvariability using three methods,which are simple differencing,slope map ofNDVI(an biomass),and principal component analysis(PCA).The change image demonstrated thatthe area of vegetation covers decrease i recent 20 years innorthwesternChina,especially intheLoessPlateauwhere precipitation decrease andtemperature increase.Only little part,such as theTianshanMoruntain area,vegetation is increased.The character of vegetation change in northwest showe that the ecological environment inthis area is becomingmore fragile,suchas shrinkingof lakes,oasis andwetland,area extending of soil erosion,salinization land,and desert because human activities and globalwarming.The correlation analysis betweenNDVI with the temperature and precipitation in northwestern China was carried out.There was significant positive correlation betwee NDVIand precipitation,and temperature was not strong correlation relatively withNDVIin the northwest China.The results showed AVHRR is reliable forregional vegetation change research after comparingwiththe change of precipitation and tempoera ture.
%K NDVI
%K vegetation cover changes
%K precipitation
%K temperature<br>NDVI
%K 植被覆盖变化
%K 温度
%K 降水
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=A41A70F4AB56AB1B&jid=F926358B31AC94511E4382C083F7683C&aid=BA893BDD4E5AFBB0&yid=2DD7160C83D0ACED&vid=9CF7A0430CBB2DFD&iid=38B194292C032A66&sid=51C74DF6A16DA45B&eid=C2F76551C0111538&journal_id=1007-4619&journal_name=遥感学报&referenced_num=36&reference_num=7