Mapping of Fractional Coverage of Paddy Fields Over China Using MODIS 250m Data

Abstract

In this study, spatio-temporal patterns of continuous paddy fields were examined using the patterns observed in metrics calculated for 1-year of MODIS over China. Four analytical approaches were used ; calculation of temporal mean, maximum and minimum layers for selected metrics showing significant spatial variability of channel 1, 2 and NDVI ; linear discriminant for input into the un-mixing analysis was derived from the same multi-temporal metrics used for the classification product using National Land Cover Data (NLCD) set of China ; the continuous percentage of paddy field was generated based on un-mixing technique with the training data derived from the above mentioned NLCD data. The derived metrics were not sensitive to time of year or the seasonal cycle and can limit the inclusion of atmospheric contamination. The comparison of 250m MODIS product with the past efforts on lkm AVHRR, MODIS and SPOT-VEGETATION product, and statistics by IRRI showed that the finer resolution and its un-mixing played a crucial role in depicting the paddy field cover over China.