Change detection of rice fields after the Great East Japan Tsunami using time-series MODIS data

The 2011 Great East Japan Tsunami destroyed rice agriculture in east coastal area of Japan, especially in Fukushima Prefecture and Miyagi Prefecture. The tsunami damaged approximately 23,600 hectares of cultivation area in the region. Monitoring the effect of rice area after the Tsunami is critical to provide agronomic planners with valuable information to devise effective crop management strategies. This study aims to investigate the change detection of paddy rice after the disaster using Moderate Resolution Imaging Spectroradiometer (MODIS) data from 2010 to 2011. The procedure of data processing consists of four steps: (1) data pre-processing to produce the time-series Normalized Difference Vegetation Index (NDVI) MODIS data; (2) data filtering of the time-series NDVI data using wavelet transform; (3) paddy rice mapping using support vector machine (SVM) and accuracy assessment, and (4) examination of paddy rice. Primary mapping results compared with ground reference data indicated close agreement between the two datasets. The paddy rice areas affected by the 2011 Tsunami were spatially distributed along the coastline. However, results revealed a significant change of paddy rice cultivation between 2010 and 2011. We expect this study can provide useful information for agronomic management in tsunami-affected area in Japan.