Hazard assessment of debris flows in the Wenchuan earthquake-stricken area, South West China
Hazard assessment of debris flows in the Wenchuan earthquake-stricken area, South West China
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DOI：
10.1007/s10346-017-0824-9
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发表时间：
2017-10-01
期刊：
影响因子：
6.7
通讯作者：
Cai, Fei
中科院分区：
文献类型：
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作者：
Chang, Ming;Tang, Chuan;Cai, Fei
位于中国西南部四川省都江堰市的龙溪河流域属于2008年5月12日汶川地震的地震区。斜坡上存在大量松散的同震物质，这些物质在后来的岁月中成为泥石流的源物质。2010年8月13日，在研究区，共有12个泥石流，由强降雨引发。采用FLO-2D数值分析软件对泥石流强度进行了数值模拟，包括泥石流运动速度和最大流深。将实测扇展与模拟结果进行对比，并采用评价参数Omega验证模拟的准确性，结果表明Omega值在1.37 ~ 1.65之间，模拟效果较好。本研究还估计了不同重现期（分别为20年、100年和200年）的洪水过程线，以进行泥石流情景模拟，并遵循瑞士和奥地利的标准，建立了泥石流危险性分类模型的基础上的泥石流强度和重现期相结合。这项研究区分了三个危险等级：低，中，高。该方法生成的泥石流危险度分布图可用于汶川地震灾区的灾害预防。
The Longxi river basin with the city of Dujiangyan, in the Sichuan province of South West China, belongs to the seismic area of the May 12, 2008 Wenchuan earthquake. Lots of loose co-seismic materials were present on the slopes, which in later years served as source material for rainfall-induced debris flows. A total of 12 debris flows, were triggered by heavy rainfall on August 13, 2010 in the study area. The FLO-2D numerical analysis software was adopted to simulate debris flows intensity, including movement velocities and maximum flow depths. A comparison of the measured fan spreading with the simulation results, the evaluation parameter Omega was used to verify accuracy of simulation, the results show Omega values ranging between 1.37 and 1.65 indicating relative good simulation results. This study also estimated the flood hydrograph for various recurrence intervals (20, 100, and 200 years, respectively) to perform scenario simulations of debris flows, and followed Swiss and Austrian standards to establish a debris flow hazard classification model on the basis of a combination of the debris flow intensity and the recurrence period. This study distinguishes three hazard classes: low, medium, and high. This proposed approach generated a debris flow hazard distribution map that could be used for disaster prevention in the Wenchuan earthquake-stricken area, South West China.