The application of FY-3A/MERSI in drought and vegetation monitoring in Gansu

Medium Resolution Spectral Imager (MERSI) on board the new Generation Polar-Orbiting Meteorological Satellite of China (FY-3A/MERSI) has more advantage than MODIS, NOAA/AVHRR over drought monitoring, five spectral channels with 250 m spatial resolution, which give MODIS, NOAA/AVHRR incomparable advantages in monitoring drought. As a result, FY-3A/MERSI enhances the ability to observe fine surface features and provides a new data source for drought monitoring in large area. How to turn the traditional drought monitoring method based on MODIS and AVHRR drought index of remote sensing monitoring to FY-3A/MERSI platform, so that FY-3A/MERSI play in precision drought monitoring role and has a extensive application field. Based on the FY-3A/MERSI image data, this paper built a drought monitoring retrieval method using the Temperature Vegetation Drought Index (TVDI) to monitor Gansu drought. In this paper, EOS/MODIS and FY-3A/MERSI data of July 5, 2012 and September 2, 2012 were acquired respectively and the vegetation and TVDI index of EOS/MODIS and FY-3A/MERSI were calculated in different land such as cultivated land, forestry and grassland and so on. The difference of vegetation and TVDI index of EOS/MODIS and FY-3A/MERSI were reported in this paper. Based on histogram and Feather Space methods and compared the contemporaneous MODIS and the soil moisture data, we built the relationship between MODIS/NDVI (Normalized differential vegetation index) and MERSI/NDVI of the same region at different time. The results showed that their shapes were the same in the histogram, and the range of their values had consistent region. Each kind of ground objects showed a better linear consistency, the maximum R can reach to 0.85. There are negative relationships between the Temperature Vegetation Drought Index and measured soil moisture data at the 10 and 20 cm depth, and the relationship is good for the 10 cm soil moisture data than 20 cm. FY-3A/MERSI improve China´s satellite remote- sensing independent application ability, to reduce dependence on foreign remote sensing data, to ensure that China´s timeliness and accuracy of drought monitoring is of great significance. The FY-3A/MERSI can monitor more area than MODIS, and the monitored drought is similar.