Detection of water-logging in a large number of paddy fields

摘要

On March 11, 2011, a huge earthquake hits Japan. The earthquake wreaked enormous damage on a wide area of north-eastern Japan. Many farmlands also suffered much damage. Therefor it was necessary to evaluate which paddy rice field the cultivation was carried out in. In this time I tried to detect water logging in a large number of paddy fields on a wide area, which number is over million. The study carried out using RADARSAT-2 wide mode data. All each paddy fields were classified as water logging or non-water logging by threshold. The threshold value decided automatically each scene. As a result, mapping of water logging paddy fields was successes. The overall accuracy of map evaluates 77.05% from ground truth data. The detection accuracy of wide fine mode is somewhat lower than fine mode which uses previous study. However price/area of the Wide Fine mode is about one-five of Fine mode. The Wide Fine mode of RADARSAT-2 is useful for detection of water logging in a large number of paddy fields on a wide area.