基于MODIS-NDVI的草地长势变化监测--以锡林郭勒盟为例

Monitoring Changes of Grassland Growth Based on Vegetation Index(NDVI) of MODIS——A Case Study of Xilin Gol League

基于锡林郭勒盟2002-2006年MODIS的影像数据,提取植被指数NDVI,采用最大值合成法得到旬度植被指数NDVI数据,结合地面实测数据判断锡林郭勒盟的各类草地在空间上的分布情况,结果表明根据植被指数判断的植被分类情况和全盟的植被实际分布状况基本一致。在此基础之上利用两年旬度植被指数NDVI的差值研究锡林郭勒盟草地的长势变化情况,结果表明,2002-2006年植被状况在逐渐变好。这说明植被指数可以很好反映全盟的植被长势变化状况,该方法是动态监测全盟植被长势的有效方法。

Based on the MODIS image data of Xilin Gol grassland during the period of 2002-2006, vegetation index NDVI was gained, the ten-day NDVI data was calculated using the maximum value composite method. The distribution of various type of grassland was classified by using the ten-day NDVI data combined with ground true date. The result showed that the division of vegetation determined by NDVI data was consistent with the real spatial distribution of vegetation. Then the changes in growth of Xilin Col grassland was investigated according to the variation of ten-day NDVI data between two years, the results showed that the vegetation state gradually developed better from 2002 to 2006. So the NDVI data could reflect the vegetation growth change exactly, and this method was effective to dynamically monitor the vegetation growth for the whole Xilin Col League.