The project changing from continuously flooded to intermittent flooded condition during rice cultivation is conducted in Tongnan District, Chongqing City, with a total acreage of 19,190 ha for single-cropping rice. Without the implementation of this project, which provides ditches to conduct intermittently flooded method, the backward continuously flooded method would be continued, so the scenario that rice was cultivated by continuously flooded method is the baseline scenario.