An empirical–statistical model for predicting debris-flow runout zones in the Wenchuan earthquake area
An empirical–statistical model for predicting debris-flow runout zones in the Wenchuan earthquake area
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DOI：
10.1016/j.quaint.2010.11.020
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发表时间：
2012-02
影响因子：
2.2
通讯作者：
Chuan Tang;Jing Zhu;Chang Ming;Jun Ding;Xin Qi
中科院分区：
文献类型：
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作者：
Chuan Tang;Jing Zhu;Chang Ming;Jun Ding;Xin Qi
2008年5月12日汶川大地震引发的暴雨泥石流是由滑坡泥石流再活化而成。由此产生的泥石流具有非常高的能量，并运送了大量松散的物质。其峰值流量达到了正常水平的几倍，特别是在2008年9月24日汶川地震区北川县暴雨引发的泥石流中。这种现象是由于存在大量的松散的物质沉积的地震引起的滑坡在泥石流流域。因此，现有的泥石流径流模型用于地震灾区泥石流危险区的评价会产生误差。因此，有必要建立一个合适的模型来预测汶川地震后冲积扇上可能出现的泥石流冲刷带。泥石流引发的9月24日暴雨被选中，并使用高分辨率航空摄影和SPOT 5图像进行调查，以提取一组滑坡存款量的泥石流集水区和沉积扇的尺寸。应用多元回归分析方法，建立了估算泥石流最大冲出距离和宽度的数学模型。验证结果表明，所建立的模型适用于汶川地震灾区泥石流径流带的预测。研究结果将有助于当局今后选择安全的恢复和搬迁地点，也可作为泥石流风险管理的重要依据。
Rainstorm-induced debris flows were remobilized from landslide debris triggered by the May 12, 2008 Wenchuan earthquake. The resulting debris flows had very high energy and transported large amounts of loose material. Their peak discharge reached levels several times normal, notably during the rainstorm-induced debris flows of September 24, 2008 in Beichuan County, in the Wenchuan earthquake area. This phenomenon was due to the presence of large amounts of loose material deposited by the earthquake-induced landslides in the debris-flow catchments. Therefore, errors will occur if existing debris-flow runout models are employed to assess the hazardous zones connected with debris flows in earthquake-affected areas. For this reason, it is necessary to establish an appropriate model to predict the possible debris-flow runout zones on the alluvial fans after the Wenchuan earthquake. Debris flows triggered by the September 24 rainstorm were selected and investigated using high-resolution aerial photography and SPOT5 imagery to extract a set of landslide deposit volumes in the debris-flow catchment areas and also the dimensions of the deposition fans. Applying multivariate regression analysis, a mathematical model was established to estimate the maximum runout distance and the width of the debris flows. The validation showed that the established model was suitable for the prediction of the debris-flow runout zones in the Wenchuan earthquake area. The results of the study will help authorities select safe sites for rehabilitation and relocation in the future and can also be used as an important basis for debris-flow risk management.