基于MODIS的广东省植被指数序列构建与应用

Establishment and Application of Vegetation Index Sequences in Guangdong Based on MODIS Data

植被指数是衡量植被长势的重要指标,植被指数序列有助于准确地认知植被覆盖、土地利用和土壤水分的时空变化规律,以及进行干旱和植被生长监测。利用2004—2006年的MODIS数据,选择RVI、NDVI和EVI三种植被指数,采用最大值合成法进行广东省植被指数序列构建。按照不同植被覆盖对三种植被指数的年际变化规律进行分析,并通过NDVI进行植被覆盖度计算以及植被覆盖等级分类来分析植被的空间分布。结果表明,建立的植被指数序列能真实地反映植被生长规律,植被覆盖度和广东地区的植被实际分布状况一致。说明建立植被指数序列是动态监测广东省植被长势的及植被环境的变化的有效方法。

Vegetation index （VI） is an important criterion to evaluate vegetation condition. VI time series can be used to judge the spatial-temporal change rules of the vegetation coverage, land use and soil moisture, also they can be used to monitor drought and vegetation condition. Three kinds of vegetation indices, i.e., ratio vegetation index （RVI）, normalized difference vegetation index （NDVI） and enhanced vegetation index （EVI）, were selected to establish the time series for Guangdong province using maximum value composites （MVC） based on MODIS data in 2004-2006. The rules of vegetation growth were analyzed in different vegetation cover type for the three vegetation indices. The vegetation coverage was computed by NDVI and classified to analyze the spatial distribution of vegetation in Guangdong. The results showed that the VI time series could reflect the rules of vegetation growth and change exactly. The vegetation coverage was consistent with the real spatial distribution of vegetation. All these showed that building VI time series were an effective method to monitor the vegetation growth and vegetation environment change dynamically for Guangdong province.