Three Landsat TM data acquired in September 1984,1986,1992 and MOS-1/MESSR data acquired in September 1993 were analyzed to obtain a spatial variability map of the rice yield in central Hokkaido. For extracting paddy fields, another four Landsat TM data acquired in May, June and July were also used. Satellite images of paddy fields were superimposed on the administrative district mesh map based on the Digital National Land Information of the Geographic Survey Institute. The statistical reports on agriculture, forestry and fisheries in Hokkaido were used as ground truth data. The spatial variability of rice yields was well explained by the multiple regression model using TM band 2,band 4 and NDVI (Normalized Difference Vegetation Index) in 1984,1986 and 1992 when the municipalities in the northern part of the study area were excluded (coefficient of determination was 0.81-0.87). The coefficient of the model varies with the year. In 1993,when the rice yield was mainly limited by sterility, there was a close relation between the digital number of MESSR band 2 and the yields of municipalities, and the logistic curve was applied to estimate the yields.
