四川泸定MS6.8地震灾害主要特征分析

A Study on the Main Characteristics of Disaster by the Luding MS6.8 Earthquake

摘要:

四川泸定6.8级地震是继2013年芦山7.0级地震至今,四川境内遭受灾害面积最大、死亡人数最多的一次地震,造成了一定程度的房屋和基础设施损坏,诱发了大量的地质灾害,具有明显的区域特点。本文基于四川省抗震救灾指挥部和地震现场工作队的一手资料,从灾情获取的时间序列、震害的空间分布、生命损失、建筑物破坏、地震地质灾害的强度等方面开展了本次地震的灾害特征分析。初步得到如下认识:①黑箱期时间为1.5h,死亡人数统计比小于1%,24h获得了半数以上伤亡信息,符合中强地震灾情渐进式获取的一般规律; ②本次地震影响面较广,有感面积为816194km²,烈度Ⅵ度区域以上面积为19089km²,Ⅸ度区面积为280km²,与一次7级地震受灾范围相当; ③地震灾害重且破坏集中,截至2022年9月11日17时共造成93人死亡,25人失联,导致房屋垮塌415间,严重损坏5566间,一般损坏19890间,新增有威胁对象的地震地质灾害点565处,其中,约92%的死亡人员地点、68%的地震地质灾害点、多数的毁坏及严重破坏房屋位置,集中分布在Ⅷ度和Ⅸ度区; ④滑坡、崩塌等次生地质灾害是造成本次地震人员死亡最主要的原因,占总死亡(含失联)人数的86%。

Abstract:

The Luding M_S6.8 earthquake is the one which has caused the largest disaster-stricken area and the biggest death toll in Sichuan Province since Lushan M_S7.0 earthquake in 2013,which also caused a certain level of damage to buildings and fundamental facilities,and triggered extensive geological hazards. Based on the first-hand data from provincial earthquake relief headquarter and disaster investigation teams,this article processes the data and conducts an analysis on the disaster characteristics of Luding M_S6.8 earthquake from different aspects,including time series of disaster information acquisition,spatial distribution of disaster characteristics,life loss,building damage and earthquake-induced geological hazards. Through analysis,preliminary conclusions are drawn as below:①The black box period lasts for 1.5h,the statistical ratio of mortality is less than 1%,over half the amount of information on casualties is obtained within 24h,which conforms with the status of disaster information acquisition after moderately strong earthquake strikes;②Many regions are affected by the earthquake,the total sensible area is up to 816194km²,the area of seismic intensity Ⅵ and above is 19089km²,the area of seismic intensity Ⅸ and above is 280km²,the affected area equals to that of a M_S7.0 earthquake;③Damages are huge and concentrated. By the time of 5PM,September 11,2022,93 people died,25 people went missing,415 buildings collapsed,5566 buildings were heavily damaged,19890s buildings were moderately damaged,565 new earthquake-induced geological hazard spots with potential to cause harm are added to the list,92% of the places where the victims were found,68% earthquake-induced geological hazard spots and most destroyed or heavily damaged buildings are distributed in the area of seismic intensity Ⅷ and seismic intensity Ⅸ;④Secondary geological hazards such as landslide and mountain collapse are the major cause of death,the proportion of their victims(missing people included)is up to 86%.