Glacial debris flows occurring on the Tibetan Plateau consistently result in significant property damage and loss of human life. A comprehensive field investigation was conducted in Tianmo valley along the Sichuan-Tibet Highway to reveal the dynamics of a debris flow that occurred on 11 July 2018. Furthermore, a depth-averaged multiphase debris flow model was proposed and employed to reconstruct the characteristics of the debris flow. The model derivation, implementation, evaluation, and application were presented to demonstrate its performance. The Voellmy model was chosen because it adequately accounts for both basal frictional effects and the entrainment phenomenon. The entrainment processes, the ice melting, and the lubrication effect, were also taken into consideration. Based on the numerical results combined with field investigation data, the kinetic characteristics of the glacial debris flow were analyzed. The Tianmo valley has a small area, but the volume and erosion rate of debris flows were much larger than that of two-phase debris flows in the same location due to ice melting. The simulation results demonstrated that the glacial debris reached a peak velocity of 20 m/s. Additionally, the volume of the debris flow increased by 50% due to the erosion over a short runout distance of approximately 4,000 m. This increase was a result of the high velocity and abundant entrainment sources on the slope. This study aims to improve understanding of the high velocity and destructive potential of debris flows in the Tianmo valley.

中文翻译：

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青藏高原天魔谷冰川泥石流动力学特征初步研究

青藏高原发生的冰川泥石流持续造成重大财产损失和人员伤亡。对川藏公路沿线天磨谷进行了全面的现场调查，揭示了2018年7月11日发生的泥石流动力学。此外，提出了深度平均多相泥石流模型，并用于重建泥石流的特征。泥石流。模型的推导、实现、评估和应用都被展示出来，以展示其性能。选择 Voellmy 模型是因为它充分考虑了基本摩擦效应和夹带现象。夹带过程、冰融化和润滑效果也被考虑在内。根据数值结果结合野外调查数据，分析了冰川泥石流的动力学特征。天磨谷面积虽小，但由于冰雪融化，泥石流的体积和侵蚀速度远大于同一地点的两相泥石流。模拟结果表明，冰川碎片的峰值速度达到20 m/s。此外，由于约 4000 m 的短跳动距离的侵蚀，泥石流体积增加了 50%。这种增加是由于斜坡上的高速度和丰富的夹带源造成的。本研究旨在加深对天磨谷泥石流的高速和破坏潜力的了解。