基于TVDI的西藏地区旱情遥感监测

TVDI-Based Remote Sensing Monitoring of Droughts over Tibet Plateau

西藏大部分地区属干旱或重干旱区,干旱发生较为频繁,是影响农牧业生产最严重的灾害之一。文章利用拉萨接收站的中分辨率成像光谱仪(MODIS)资料提取的归一化植被指数(NDVI)和地表温度(ST),构建ST-IND-VI特征空间,依据该特征空间设计的温度植被旱情指数作为旱情指标,找出适合该地区的旱情判别模式,以2005～2008年6～7月同时段西藏地区卫星资料、气象旱情监测结果以及土壤相对湿度观测数据为例,进行旱情对比分析。结果表明,利用温度植被旱情指数(TVDI)法对西藏地区进行夏季干旱动态监测是可行的。

Most parts of the Tibetan Plateau belong to the region frequently attacked by droughts or heavy droughts,which is one of most serious disasters influencing agriculture and pasturing production in Tibet.Using NDVI（Normalized Difference Vegetation Index） and ST（Surface Temperature） gained from MODIS（Moderate Resolution Imaging Spectroradiometer） at the Lhasa receiving station,the ST-INDVI characteristic space is constructed and a drought discriminating method is devised according to TVDI（Temperature-Vegetation Dryness Index） as the drought guideline,along with the satellite datasets for the same periods（June and July） from 2005 to 2008,and the monitoring results of meteorological droughts and soil moisture observation indicate that the TVDI method is applicable in the Tibetan Plateau for monitoring droughts with satellite datasets.