Detection and mapping of soil liquefaction in the 2011 Tohoku earthquake using SAR interferometry
Detection and mapping of soil liquefaction in the 2011 Tohoku earthquake using SAR interferometry
复制标题
使用 SAR 干涉测量法检测 2011 年东北地震中的土壤液化并绘制地图
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
T. Matsuoka
中科院分区：
文献类型：
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作者：
K. Ishitsuka;T. Tsuji;T. Matsuoka
我们通过分析2011年东北地震引起的地表变化，在日本关东地区使用合成孔径雷达（SAR）干涉测量法确定了土壤液化的区域。表面散射特性的变化进行了评估，使用相位校正的相干性，计算从SAR数据的反射强度（振幅）。通常，相干性的丧失（去相关）被简单地认为代表了灾难中受损的区域。然而，时间去相关也可以引起有序的表面覆盖变化，除了灾害损失。因此，我们使用一个相干变化阈值来区分显着的去相关引起的土壤液化所产生的有序表面覆盖的变化。此外，局部表面位移估计使用相位信息从SAR数据。我们的研究结果相比有利的沙沸和航空摄影的调查，表明来自SAR数据的表面变化与土壤液化。研究结果表明，液化主要发生在东京湾沿岸沿着和东京都内川沿岸，地面沉降分布广泛。
We have identified areas of soil liquefaction by the analysis of surface changes caused by the 2011 Tohoku earthquake, using synthetic aperture radar (SAR) interferometry in the Kanto region of Japan. Changes in surface scattering properties were evaluated using phase-corrected coherence, computed from the reflective intensity (amplitude) of SAR data. Often, the loss of coherence (decorrelation) is simply considered to represent areas damaged from the disaster. However, temporal decorrelation could also be induced by ordinal surface cover change in addition to disaster damage. Therefore, we use a coherence change threshold to discriminate significant decorrelation caused by soil liquefaction from that produced by ordinal surface cover changes. Moreover, local surface displacements are estimated using phase information from the SAR data. Our results compare favorably with those from surveys of sand boils and aerial photography, showing that surface changes derived from SAR data are associated with soil liquefaction. Our results demonstrate that soil liquefaction occurred mainly near the waterfront along Tokyo Bay and the Tone River, and ground subsidence was widely distributed.