青藏铁路沿线雪灾风险评估

A risk assessment of snow disaster along Qinghai-Tibet Railway

雪灾是青藏铁路及其沿线地区所面临的严重自然灾害之一,对其风险等级进行科学评估,是制定应急方案、确保青藏铁路安全运行的重要基础。本文基于历史雪灾数据和铁路相关数据,选择27项指标构建青藏铁路及其沿线的雪灾综合风险评估体系,对青藏铁路沿线积雪雪灾、雪崩雪灾和风吹雪雪灾的致灾危险性、铁路系统的脆弱性进行了综合分析。分析表明:青藏铁路沿线雪灾高风险区分布在唐古拉-安多路段,雪灾中等风险区主要分布在天峻-乌兰、五道梁-安多等2个路段,雪灾低风险区主要集中在西宁-天峻、德令哈-格尔木和那曲-拉萨等3个路段。从整个青藏铁路沿线来看,青南高原路段是青藏铁路沿线雪灾综合风险等级最高的区域。

The main natural calamity affecting land transportation routes are floods, snow,heavy fog, landslides, mudslides, strong winds, hail, thunder and lightning, and extreme temperatures. The interrupted transportation will have a huge negative effect on the socio-economic system. The World Economic Cooperation and Development Organization and the International Future Plan clearly regard transportation as one of the major risk engineering fields that must be given attention in the 21st century. Since the 1990s, relevant researchers have conducted indepth investigations and comprehensive studies on geological, frozen soil, and meteorological disasters along China’s main traffic lines, and discussed the degree of natural disasters along the main lines of traffic, their causes, and disaster mitigation countermeasures. Since 2000, with the gradual improvement of the theoretical system of risk assessment for major construction projects and lifeline projects, specific methods for quantitative identification, estimation, evaluation and decision-making have been proposed, and much research has been carried out on the risk factors, vulnerability and risk degree of lifeline engineering and railway transportation system.A basic evaluation model has been established and corresponding evaluation software has been developed. In particular, it is of great significance to conduct quantitative studies of disaster risk and vulnerability of the risk bearing body based on natural disasters and road maintenance data along the Eurasian Continental Bridge. With the increasing uncertainty brought about by global climate change, research on natural disaster risks faced by China’s high-speed railways,highways and urban public transportation systems has become a hot spot. Snow disaster is one of the severe natural disasters along the Qinghai-Tibet Railway and its neighboring areas. Assessment of its risk grade is an important foundation for making emergency and ensuring safety operations of the Qinghai-Tibet Railway. We constructed a comprehensive risk assessment system of snow disaster in this region composed of 27 indexes based on historical snow disasters and relevant railway data. And then, the comprehensive analyses are conducted for three types of snow disaster risk of perpetual snow, avalanche and wind-blown and vulnerability of railway network. The result shows that, the high risk region of snow disasters along the Qinghai-Tibet Railway is mainly distributed in Tanggula-Anduo section, the medium risk region is mainly distributed in Tianjun-Wulan and Wudaoliang-Anduo sections, and low risk regions are in XiningTianpeng, Delingha-Golmud and Naqu-Lhasa road sections. As a whole, the section in southern Qinghai Plateau became the highest comprehensive risk region for snow disaster along the Qinghai-Tibet Railway.