基于FLO-2D的西藏若如村泥石流危险性分析

若如村泥石流堆积扇前缘分布有青藏公路、青藏铁路以及在建的青藏高速公路三大交通工程,对其危险性研究十分必要。在详细野外调查的基础上,采用FLO-2D软件对青藏铁路、青藏高速公路、若如村及主排导槽的泥石流危险性进行研究。基于1998-2018年历史日降雨数据,模拟了5%、2%和1%降雨频率以及另外8种极端降雨条件下若如村泥石流的暴发过程,分析了重点威胁区域的泥石流流动及堆积特征。将模拟情况与实际堆积范围进行对比,精确率为68. 7%,在合理误差范围内。最后将泥深、流速与暴发频率相结合,得到泥石流危险性评价图,并为其灾害分析、预警及发展规划提出建议。

Risk assessment of debris flow in Ruoru Village, Tibet Based on FLO-2D

Three major traffic projects: Qinghai-Tibet Highway, Qinghai-Tibet Railway and Qinghai-Tibet Highway under construction distributes in the front of debris flow accumulation fan in Ruoru Village, so it is necessary to assess the risk of debris flow. Based on a detailed field investigation, this paper uses FLO-2D software to study the debris flow risk of Qinghai-Tibet Railway, Qinghai-Tibet Expressway, Ruoru Village and main drainage channel. Based on the historical rainfall data from 1998 to 2018, the 5%, 2% and 1% rainfall frequency and the other eight extreme rainfall conditions of the Ruoru Village debris flow outbreak process were simulated, and the debris flow accumulation characteristics of the key threat areas were analyzed. The simulation was compared with the actual situation, and the accuracy was 68.7%, which is within the reasonable deviation range. In addition, the mud depth, flow rate and frequency of outbreaks were combined to obtain a debris flow risk assessment map to provide recommendations for disaster analysis, early warning and development planning.