川藏铁路四川段沿线强风特征及其危险性评估

Characteristics and Hazard Assessment of Strong Winds along the Sichuan Section of the Sichuan Xizang Railway

强风是影响川藏铁路安全建设与运营的主要气象灾害之一.为减轻或避免强风灾害对川藏铁路建设与运营安全的影响,以四川段为例,利用200余个地面区域自动气象站2009-2022年的10 m高度测风数据,分析了川藏铁路四川段沿线强风分布特征,并根据强风对施工期与运营期的不同影响,分别建立不同评估指标评估其强风危险性.研究结果表明:泸定县以西路段受高原地形影响,强风频次较高,大部路段各月大风日数超过5 d,年均极大风速超过10.0 m/s,极大风速盛行风向以偏北风为主,其中理塘和春季分别是大风日数最多的路段和时段.泸定县以东路段受盆地地形影响,强风频次较低,全年大风日数可忽略不计,年均极大风速为5.0~10.0 m/s,全年极大风速盛行风向以偏东风为主.川藏铁路四川段沿线施工期与运营期强风危险性等级分布较为一致,其中较高及以上等级区域均集中于雅江县西部至理塘县路段.基于区域自动气象站数据开展川藏铁路沿线强风特征及其危险性分析更加精细,可为川藏铁路四川段建设与运营期的强风防灾减灾提供参考.

Strong wind is one of the main meteorological disasters affecting the safe construction and operation of the Sichuan Xizang Railway.In order to reduce or avoid the impact of strong wind disaster on the construction and operation safety of the Sichuan Xizang Railway,this article took the Sichuan section as an example,analyzed the distribution characteristics of strong winds along the Sichuan section of the Sichuan Xizang Railway using wind measurement data from over 200 automatic meteorological stations at a height of 10m over the past 10 years.Based on the different impacts of strong winds on the construction and operation periods,different evaluation indicators were established to evaluate the strong wind risk.The research results showed that the western section of Luding County was affected by the plateau terrain,with a higher frequency of strong winds.Most sections had more than 5 strong wind days per month,and the average annual maximum wind speed exceeded 10.0 m/s.The prevailing wind direction of the maximum wind speed was mainly northerly,with Litang and spring being the sections and periods for the highest number of strong wind days,respectively.The section of the road at east of Luding County was affected by the terrain of the basin,and the frequency of strong winds was relatively small.The number of strong wind days throughout the year could be ignored.The average annual maximum wind speed was 5.0-10.0m/s.The prevailing wind direction for the annual maximum wind speed was mainly easterly.The distribution of strong wind hazard levels along the Sichuan section of the Sichuan Xizang Railway during the construction and operation periods was relatively consistent,with areas of higher or higher levels above concentrated in the western part of Yajiang County to Litang County.A more detailed analysis of the characteristics and hazards of strong winds along the Sichuan Xizang Railway based on regional automatic meteorological station data could provide reference for prevention and reduction of the strong wind disaster in the construction and operation of the Sichuan section of the Sichuan Xizang Railway.