2006 年 26 巻 2 号 p. 146-153
In this study, spatio-temporal patterns of continuous paddy fields were examined using the patterns observed in metrics calculated for five years of MODIS over East Asia. Firstly, discrimination scores were computed to determine optimal images among seven types of MODIS derived metrics in channel 1, 2 and NDVI supplemented by ASTER classification result. The given scores were stable over five years to distinguish paddy from other land cover category. Then fractional coverage of paddy field were mapped over five years and they resulted in the consistency with the training data derived from ASTER. The derived metrics and paddy fields fractional coverage maps were not sensitive to year to year or the annual cycle and can limit the inclusion of atmospheric contamination. Finally our MODIS product were compared with the past efiorts on continental-scale land cover monitoring with AVHRR and MODIS sensors, and statistics by IRRI showed that the others' estimation except our product overestimate the paddy fields covers. The un-mixinng technique with difierent spatial resolution sensors played a crucial role in depicting the paddy fields cover.