Estimating Paddy Rice Area in Southren China With Multi-Temporal MODIS Data

Paddy rice is one of the most important crops in the world. Information of the area and spatial distribution of paddy rice is significant for food security, water resources management, and greenhouse gas (methane) emissions. Paddy rice field is characterized by an initial period of flooding and transplanting, during which period open canopy (a mixture of rice crops and surface water) exists. The present algorithms for paddy rice recognition are mainly based on the unique physical features of paddy rice and the vegetation indices, which are sensitive to dynamics of the canopy and surface water content. In this study, the rice growth calendar data and the cropping pattern (e.g., single rice or double rice) information were used to improve present phenology-based rice recognition approach by determining the potential temporal window of flooding and transplanting periods over a year. Other land cover types (e.g., snow, evergreen vegetation and permanent water bodies) with potential influences on paddy rice identification were removed (masked out) due to different temporal profiles. The results showed that the estimated rice area is in line with the provincial agricultural statistics with R2and slope are 0.951, 1.049, respectively, and the relative errors of the different province are between -15.81% to 25.75%.