“东方之星”翻沉事件风灾现场调查分析与致灾风速估算  

Field Investigation and Analysis of Wind Disaster and Estimation of Disaster Wind Speed of the Capsizing Accident of Cruise Ship “Oriental Star”

作　　者：王凯[1] 梁益同[1] 刘敏[1] WANG Kai;LIANG Yitong;LIU Min(Wuhan Regional Climate Center,Wuhan 430074)

机构地区：[1]武汉区域气候中心

出　　处：《气象》2020年第1期98-107,共10页Meteorological Monthly

基　　金：国家重点研发计划(2018YFC1508001)资助

摘　　要：以"东方之星"翻沉事件为例,前期研判结合现场调查分析认为:2015年6月1日21:00-21:15,事发区域出现雷暴、大风、暴雨等灾害性天气,持续时间在30 min左右;此次灾害过程以风灾最为严重,呈现空间分布不连续、小尺度等特点。调查结果表明:事发区域沿江两岸风场同时存在垂直切变和水平切变,雷达监测显示,中气旋从长江西岸向东岸移动,具有涡旋特征。本次过程以风灾为主,受灾严重区域集中在事发点以北8 km范围内,距事发点4 km左右长江东岸的四台村受灾最为严重,该区域风切变强烈,有辐散迹象。受灾体主要为树木、作物、房屋、船只等,对树木造成的破坏最大,受灾点共计31处,占总调查点数的72.1%。事发区域近地面长江西岸树木折断或倒伏方向以东南向为主,长江东岸树木折断或倒伏方向以东向为主,倾倒方向具有明显的一致性,但长江两岸存在水平切变,风向偏转近90°。通过实际灾情结合力学模型的方式,探索风灾定量评估方法,以受灾严重的杨树为个例分析对象,采用抗倾覆力矩计算方法,估算致灾风速,结果显示,强风是造成此次事件的重要原因之一,致灾风速为28.7 m·s^-1,达10级以上。Take the capsizing accident of cruise ship"Oriental Star"as an example.The analysis of the previous study and the field investigation shows that on 1 June 2015,from 21:00 BT to 21:15 BT,severe weather such as thunderstorms,strong winds,heavy rains and tornadoes hit the investigation area.The duration was about 30 minutes.The disaster process was characterized by the most severe windstorms,with spatial discontinuities and small scales.The survey results show that there were vertical shear and horizontal shear in the wind field along the Yangtze River in the accident area.Radar monitoring showed that the mesocyclone moved from the west bank of the Yangtze River to the east bank,having vortex characteristics.This process was mainly based on windstorms.The severely affected area was concentrated within the range 8 km north of the accident,the Sitai village on the east bank of the Yangtze River,which is about 4 km away from the accident,was the most seriously affected,This region had strong wind shear and signs of divergence.The main affected objects were trees,erops,houses,boats,etc.,eausing the most damage to trees,a total of 31 disaster sites,accounting for 72.1%of the total survey sites.In the accident area,the trees on the west bank of the Yangtze River were broken or the direction of lodging was mainly southeastward,the trees on the east bank was mainly eastward.So,the direction of the trees dumping was clearly consistent.However,there were horizontal shears on both sides of the Yangtze River,and the wind direction was deflected by nearly 90°.The quantitative evaluation method of wind disaster was explored by combining actual disaster with mechanical model.Take the severely affected poplar as an example,the anti-overturning moment calculation method was used to estimate the disaster rate.The results show that strong wind was one of the important causes of the accident.The wind speed of the disaster was 28.7 m·s^-1,reaching Grade 10 or above.

关 键 词：现场调查 致灾风速 估算 

分 类 号：P429[天文地球—大气科学及气象学]