汶川地震触发陕西省境内地质灾害灾险情特征

CHARACTERISTIC OF GEO-HAZARD IN SHAANXI PROVINCE BY WENCHUAN EARTHQUAKE

在实地调查、汶川地震震后次生地质灾害隐患排查成果的基础上,结合县市地质灾害调查数据,从灾情和险情两个方面,对汶川地震触发地质灾害灾险情的致灾灾险情、灾种、类型等特征进行了较系统的分析对比。进一步比较了陕西在汶川地震触发地质灾害受灾省份中的情况,并对地质灾害趋势做了初步预测。研究表明,灾险情集中分布在龙门山构造带向陕西境内的延伸部分,险情比灾情分布范围广。灾险情的灾种都以崩塌为主,其次为滑坡,地震对地质体的震动触发作用明显。机关学校是汶川地震触发陕西境内地质灾害的主要受灾对象。陕西受汶川地震触发地质灾害的灾险情轻于四川、甘肃,三省地质灾害震前均较为严重,地震触发地质灾害的影响具有长期性,未来陕西境内地质灾害发生的频率可能增大。

Based on materials of field investigation and geological hazard situation inspection after wenchuan earthquake,in this paper,from the aspects of geological hazard case and dangerous case,the author analyze case distribution,type,grade of geo-hazard triggered by Wenchuan earthquake.Furthermore the author give an evaluation of geo-hazard triggered by Wenchuan earthquake in shaanxi province compared with in Sichuan and Gansu province,in the end trend of geo-hazard in shaanxi province is predicted preliminary.Wenchuan earthquake causes geological hazard of 302 cases in Shaanxi province.The distribution of those geological hazard is chiefly in Baoji City,Hanzhong City,Xianyang City and Shangluo City,those geological hazard lead to two people dead and 13 injuries and great direct economic loss.Geological hazard case type is mainly landslide,which proportion is 85.7% in the whole of the geological hazard case type proportion.Geo-hazard case grade is mainly small grade of geological hazard,however middle grade of geological hazard lead to main direct economic loss.Geological hazard-causing object is mainly settlement and secondly institution and schools.Geological hazard danger cases caused by Wenchuan earthquake is chiefly in Hanzhong City,Baoji City,Xianyang City and Ankang City.Geological hazard danger case type is mainly landslide.and geological hazard danger case grade is mainly small grade.Geological hazard causing object is mainly settlement and secondly institution and schools also.The geological hazard case and danger cases have the following five characteristics：First,geological hazard and danger case mainly distributes the extension of Longmenshan Mountain geological structure,and the distribution of danger cases is more widely than the distribution of geological hazard.Second,geological hazard case type is mainly landslides.Third,geological hazard-causing object is mainly institution and schools,which is also prevention and control emphasis of geological hazard in the future.Fourth,small grade of geological hazard cases is the largest in all hazard cases.Fifth,relation of geological hazards in scale and geological hazard grade is the ＂U＂ shaped relationship.Damage caused in Shaanxi province by Wenchuan earthquake is relatively light than which of Sichuan and Gansu province.Shaanxi province is one of serious provinces in geological hazard,so the frequency of geological hazards could be increased in the future.Two suggestions of deepening research of geological hazard are taken out,one is to further enhance the analysis of geological structure and earthquake and geological hazard,and two is strengthening the rule and characteristics of the geological hazard.