雅鲁藏布江色东普沟崩滑-碎屑流过程模拟及运动特征分析

2018年10月17日，西藏自治区雅鲁藏布江西岸色东普沟发生冰崩岩崩，冲刷侵蚀下部冰积堆积体和沟床松散堆积物，形成碎屑流冲入雅鲁藏布江，堆积后形成堰塞坝堵塞河道，严重影响当地居民安全和社会经济发展。本文基于真实遥感影像建立三维数值模型，利用DAN3D分析其动力学特征，选取Frictional-Voellmy复合模型反演得到碎屑流堆积特征、滑体运动速度和铲刮深度等动力特征参数，与实际勘察结果基本一致，具有较好的可靠性。在野外勘察基础上，结合高密度电阻率法揭示了色东普沟崩滑-碎屑流堆积特征，结果表明DAN3D能够较好地模拟滑体的堆积形态和最大厚度，验证了DAN3D模拟的有效性，研究结论及方法对于此类灾害的机理研究及未来防治工程提供了新的研究思路。

Numerical runout modeling and dynamic analysis of the ice avalanche-debris flow in Sedongpu Basin along Yarlung Zangbo River in Tibet

On October 17, 2018, a massive ice avalanche-debris flow occurred in the Sedongpu Basin on the left bank of the Yarlung Zangbo River in Tibet. The sliding mass scoured the glacial deposits and loose deposits in the gully bed and then transformed into a debris flow. Eventually, a barrier dam was formed and blocked the Yarlung Zangbo River, which seriously affected the safety of residents and social and economic development. In this paper, a three-dimensional numerical simulation of this event was performed based on remote sensing. A dynamic analysis (DAN3D) model was utilized to analyze the dynamic characteristics of sliding mass, and the Frictional-Voellmy composite model was selected to reproduce debris flow accumulation characteristics, movement speed, and scraping depth. The simulation results are consistent with the actual survey results and have good reliability. Based on field investigation, the electrical resistivity tomography method was used to reveal the post-event accumulation characteristics of the ice avalanche-debris flow in Sedongpu gully. The results showed that DAN3D could well simulate the accumulation shape and maximum thickness of sliding mass, which verified the effectiveness of DAN3D simulation. The results of the study can help forecast similar events and provide new research ideas for the mechanism research of such disasters for future prevention and control projects.