云南怒江流域植被光谱特征季节变化研究

Seasonal Variation of Vegetation Spectral Characteristics at Yunnan Nujiang River Basin

[目的]分析云南怒江流域植被的季节变化规律。[方法]在大量野外调查和影像分析的基础上,参照《云南植被》将云南怒江流域植被划分为19种自然植被和1种人工林。以2009年TM影像为数据源对保护区植被进行人机交互解译,利用MODIS NDVI数据提取各类型的MODIS NDVI季节变化信息,构建5个光谱特征季节变化指标来对研究区植被进行了全年分析。[结果]NDVIjmax:常绿类型大于落叶,森林大于灌丛及灌草丛,草甸类型最小。NDVIjmin:森林类型大于灌丛及灌草丛,草甸类型最小。NDVIjm:常绿阔叶林类型处于较高水平,其次为针叶林类型以及落叶阔叶林、人工林和竹林,灌草丛及草甸类型相对较低,2种草甸类型最小。NDVIjr:一般是落叶大于常绿,灌丛及灌草丛类型大于其他类型,水热好的大于其他区域类型。NDVIja:基本上是森林类型大于灌丛及灌草丛,草甸类型最小。[结论]构建的5个光谱特征季节变化指标较好地反映了研究区植被的季节变化规律。

[Objective]The aim was to analyze the seasonal variation law of vegetations in Yunnan Nujiang River basin.[Method]Based on comprehensive field survey and image analysis,it developed a classification system for Nujiang River basin based on remote sensing,in which the basic units is reference to the subtype in Yunnan Vegetation.In total,there are 19 types of natural vegetation and plantation forest.Make use of TM images in 2009 as data source to interpret the vegetation on the protected areas by human-computer interaction,then used MODIS NDVI data to extract various types of information on seasonal variation of MODIS NDVI.5 indexes of seasonal variation of vegetation spectral characteristics were constructed to analysis vegetation variation.[Result]As for NDVIjmax,evergreen type was more than deciduous type;forest was more than shrubs and shrub-grassland;meadows were the minimum.As for NDVIjmin,forest was more than shrubs and shrub-grassland;meadows were the minimum.As for NDVIjm,evergreen broad-leaved forest was high,the secondly for coniferous forest,deciduous broad leaved forest,plantation and bamboo forest;shrubs and meadows were relatively lower;two kinds of meadows were the minimum.As for NDVIjr,deciduous type was generally more than evergreen type;shrubs and shrub-grassland were more than the other types;the regions with good humidity and temperature were more than the other regions.As for NDVIja,forest was more than shrubs and shrub-grassland basically;meadows were the minimum.[Conclusion]The indexes reflect the seasonal changes of vegetation evidently.