干旱的频繁发生已经成为影响西藏农业生产最严重的自然灾害之一,干旱给农业造成的巨大损失引起了各级政府部门的高度重视。对地观测卫星(EOS)中分辨率成像光谱仪(MODIS)传感器因其具有高时间分辨率、高光谱分辨率、适中的空间分辨率等特点,非常适合大范围、长时期、动态的干旱监测。文中利用MODIS数据提取归一化植被指数(NDVI)和地表温度(LST),构建NDVI-TS特征空间,依据该特征空间得到的温度植被干旱指数进行西藏的旱情分析。研究表明:此种方法适用于西藏旱情监测,同时它也是一种便捷、高效和近实时的适合大面积干旱监测的方法。
The frequent occurrence of drought has become one of the natural disasters which have severely affected agricultural production in Tibet. Using NDVI (Normalized Difference Vegetation Index) and ST (Surface Temperature) gain from MODIS (Moderate Resolution Imaging Spectroradiometer), The NDVI -TS characteristic space was constructed and a drought discriminating method was devised according to TVDI (Temperature - Vegetation Dryness Index) as the drought guideline. This study showed that this method is suitable for monitoring drought in Tibet and is also convenient, efficient and near - real time drought monitoring approach which may be used to monitor in the wide range.