抄録
Remote sensing is powerful technique for large area observation at once. We developed the monitoring system of near real time for agricultural disaster at coastal zone of China using NOAA/AVHRR data. Current ten-day composite of Normalized Difference Vegetation Index (NDVI) is compared with the average of ten day NDVI composite of past three years. The average NDVI images are created using the ten-day composite data of 1997-1999. To reduce the cloud noise, the maximum value of NDVI is used for ten-day composite. The negative NDVI pixels are eliminated at the calculation of the average, since there are the cloud pixels even in ten-day composite. Then, the difference NDVI values are calculated as current composite NDVI minus the average NDVI images and negative difference (<-0.1) pixels are listed as drought risk area in spring and summer. Using the difference NDVI images of Northeast China, we can realize drought damage on agricultural land and grassland.
