【摘要】 植被覆盖度指数FVC(FractionalVegetationCover)是从植被归一化指数中演化出来的反映植被盖度的指数,是很多干旱半干旱地区生态水文模型中的重要变量.本文通过该指数结合地貌特征对中国新疆南部植被进行了分类.首先按数字地面高程将整个研究区分为三个子研究区:(1)低海拔平原荒漠、丘陵区,海拔高度≤2000m,主要植被为绿洲、平原荒漠类植被;(2)亚高山、中低山地地区,海拔高度在2000～3900m,主要植被为森林、亚高山草原、山地草原、山地荒漠草原、山地荒漠;(3)高山区,海拔高度>3900m,主要植被高山垫状植被、高寒荒漠.然后对每一个子区的植被进行独立的分类.由于每一个子区的种类相对于整个区域种类减少,且具有特殊性,使分类方法从考虑研究区所有对象之间的均衡变为仅考虑每个子研究区内相对特殊的植被,分类条件放宽,再加之FVC指数的特点使得分类精度提高.在对三个子研究区进行相对独立的分类之后,再利用GIS方法,将三个子研究区合并为整体的分类图,完成对整个区域的植被分类.更多还原

【Abstract】 FVC( Fractional Vegetation Cover) derived from remotely sensed data is often associated with computation of spectral vegetation indices and their empirical relationships with fractional vegetation cover. FVC in arid and semi-arid regions is an important variation in hydrological and ecological modeling studies. Their temporal dynamicsand spatial distributions areoften needed in global circulation models ( GCMs) in order to compute the energy or water fluxes.In this article we classity the regetation types in the south of Xinjiang using FVC and DEM( Digital Elevation Model) .First we divide all study areas into three subareas:( 1 ) low altitude plain desertand hill subarea in which the altitude is below2 0 0 0 m,the main vegetation types are oasis and plain desert and semi-desert vegetation;( 2 ) subalpine which is 2 0 0 0～ 3 90 0 m in altitude,main types are forest,subalpine meadows,mountain meadows,mountain desert and semi-desert vegetation;( 3 ) alpine:in which the altitude is above 3 90 0 m,main types are Tundra,alpine desert.After dividing we independently classify for vegetation in every subarea.For the reason thatvegetation types in subarea is less than in all area and there are differentvegetation types living in different subarea,we do notneed to think how to balance all types in a whole image while classifying and just consider how to classifiy less vegetation types in someone subarea.The threshold of classifying changs widely,classifying is a subarea is easier and can trend case of reality,in addition to the feature of FVC,theresultof classifying improved.Atthe end wegetherthree subarea into one map of classification map by the method of GIS( Geographic Information System) .The result shows this method issuperior to the traditional method,and solve the confusion of vegetation classification in altitude.更多还原