COSMO-SkyMed data observation of reconstruction process in agricultural fields damaged by the March 11 2011 tsunami

To extract annual changes in paddy field areas, we analyzed COSMO-SkyMed observation data relating to an area damaged by the 2011 Tohoku earthquake. Backscattering coefficient (gamma naught: γ⁰) values were calculated for images obtained on June 4 2011, June 2 2012, and June 9 2013. Mean backscattering coefficients were calculated for each agricultural parcel using vector boundary data. Areas of relatively low backscattering coefficients correspond with fields that were flooded in relation to rice planting, or fields that have not been repaired. The area of low backscattering coefficients expanded annually between the inland area and the coastal area, showing the progress of paddy field reconstruction. The spatial distribution of COSMO-SkyMed data backscattering coefficient patterns in 2011 were similar to that of TerraSAR-X data obtained 1 day after the COSMO-SkyMed data.