Detection of Flooding Agricultural Field by Typhoon Hagibis on 2019 Using Sar Imagery

Damage detection due to Typhoon Hagibis was attempted on an agricultural field in Miyagi Prefecture, Japan, using Synthetic Aperture Rada (SAR) data. Sentinel-l data obtained immediately following the heavy rainfall was analyzed. Additionally, the possibility for damage detection by ALOS-2 PALSAR-2 data obtained four days after the rainfall was examined. Image composition of Sentinel-l data obtained directly after the rainfall and the flooding time during paddy rice transplanting is effective in detecting heavily flooded areas caused by dike breach. Flooding because of heavy rain causes a decrease in the backscattering coefficient in both the inside of the field and footpath between the fields. Pixel spacing of PALSAR-2 strip map mode data was 2.5 m and showed the disturbed pattern of the paddy fields caused by the receding floodwater.