[S-TT59_29AM1] 合成開口レーダー

[STT59-02] 台風26号による伊豆大島土砂災害の観測

*渡辺 学¹、段 理紗子²、本岡 毅¹、大木 真人¹、島田 政信¹ (1.宇宙航空研究開発機構、2.リモートセンシング技術センター)

キーワード：Full polarimetry, SAR, disaster

On October 16, 2013, Typhoon Wipha struck Izu Oshima island, and a large-scale landslide was induced by the heavy rain. Six days after the disaster, Pi-SAR-L2 observation was carried out in four different observation directions (L203201?L203204). One Pi-SAR-L observation (L03801) was carried out before the disaster on August 30, 2000 in same observation direction of L203201. The observation data were used to determine which parameters and directions are preferable to detect landslide areas. Several full polarimetric parameters, including Sigma_0, polarimetric coherence, four-component parameters, and eigenvalue decomposition parameters were obtained using PolSARPro and a self-produced programs. As pointed out by Shimada et al. [1], the change of the land cover from a forest before the disaster to bare soil after the disaster was well detected by the coherence between HH and VV. In addition to this parameter, the eigenvalues and four-component decomposition parameters have the potential to detect landslide areas. The data from observations of the bottom to the top of the landslide detect the landslide well, whereas the observation of the opposite side are not as useful. Soil from the landslide intruded into the town areas, but none of the full polarimetric parameters show any significant difference between the landslide-affected town areas and the unaffected areas.[1] Masanobu Shimada, Manabu Watanabe, Noriyuki Kawano, Masato Ohki, Takeshi Motooka, and Yutaka Wada, Detecting Mountainous Landslides by SAR polarimetry: A Comparative Study Using Pi-SAR-L2 and X band SARs, Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan, 2014, 12, No.ists29, pp. Pn9-Pn15.