Extraction of Inundation Areas Due to the July 2018 Western Japan Torrential Rain Event Using Multi-Temporal ALOS-2 Images
Extraction of Inundation Areas Due to the July 2018 Western Japan Torrential Rain Event Using Multi-Temporal ALOS-2 Images
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使用多时相 ALOS-2 图像提取 2018 年 7 月日本西部暴雨事件造成的淹没区域
DOI：
10.20965/jdr.2019.p0445
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发表时间：
2019
影响因子：
0.8
通讯作者：
Y. Maruyama
中科院分区：
文献类型：
--
作者：
Wen Liu;F. Yamazaki;Y. Maruyama
2018年6月28日至7月8日，一系列严重的飓风袭击了日本的西半部。河水泛滥，冲毁河堤，造成大面积洪灾。在这项研究中，两个事件前和一个共同事件的ALOS-2 PALSAR-2图像被用来提取在仓敷和冈山市，冈山县，日本的淹没区。首先，从三个时间的强度图像中提取水区域的阈值。2018年7月增加的水域作为淹没获得。通过后向散射强度的增加来识别被淹没的建筑区。计算事件前和事件共时相干性值之间的差异。相干性降低的区域被提取为可能的淹没区域。2018年7月16日进行的实地调查结果用于估计提取的最佳参数。最后，从强度和相干图像的结果进行了验证，通过比较基于网络的问卷调查报告和航空照片的视觉解释。
A series of heavy rainfalls hit the western half of Japan from June 28 to July 8, 2018. Increased river water overflowed and destroyed river banks, causing flooding over vast areas. In this study, two pre-event and one co-event ALOS-2 PALSAR-2 images were used to extract inundation areas in Kurashiki and Okayama Cities, Okayama Prefecture, Japan. First, water regions were extracted by threshold values from three-temporal intensity images. The increased water regions in July 2018 were obtained as inundation. Inundated built-up areas were identified by the increase of backscattering intensity. Differences between the pre-and co-event coherence values were calculated. The area with decreased coherence was extracted as a possible inundation area. The results of a field survey conducted on July 16, 2018 were used to estimate the optimal parameters for the extraction. Finally, the results from the intensity and coherence images were verified by making comparisons between a web-based questionnaire survey report and the visual interpretation of aerial photographs.