Historical Rice Field Maps of Japan

This dataset provides rice field maps of Japan from the 1980s. The rice field raster layers were created using Landsat images, by combining temporal aggregation and a phenology-base algorithm in Google Earth Engine. Each layer represents an averaged representation of the distribution of rice fields over a period of 5 years. Methods for creating the rice layers are fully described in the associated publication: Carrasco et. al. 2022. Historical mapping of rice fields in Japan using phenology and temporally aggregated Landsat images in Google Earth Engine. (Under review). The "Raw-maps" folder contains the seven rice field binary maps (seven different time periods; 1 = rice fields; 0 = non-rice fields) described in the associated publication. The "Post-processed-maps" folder contains the seven rice field maps with additional post-processing (1 = rice fields; Non-rice fields are set to NA values). This post-processing consists on (1) water-bodies masking, and (2) masking of Hokkaido municipalities where rice was not present during the last two decades. As discussed in the associated publication, rice fields were overestimated in Hokkaido. For this reason, by masking out rice fields in areas where rice fields were not present in recent times we can improve the accuracy of the mapping for this area. For this masking, we used official (field-based) data on rice field area of Hokkaido municipalities provided by the Ministry of Agriculture, Forestry, and Fisheries of Japan. Unfortunately, those data were not available at the municipality level for all prefectures. Each raster file is in geographic coordinates and has an original spatial resolution of 30 m. The accuracy of the maps is presented in the associated publication. We suggest users to check the associated documentation and to understand the uncertainties and limitations of this dataset.