摘要
区域地质灾害时空发育规律是内外地质营力共同作用的结果,大区域范围内外地质营力相对稳定,因此,地震的震源、震级、发生时间是影响大区域地质灾害时空发育规律的主要因素。为研究“5·12”汶川地震对四川省地质灾害时空发育的影响,以1998-2018年滑坡、崩塌、泥石流、地震、降雨等数据为基础,采用数理统计与空间分析方法对比分析了汶川地震前后四川省主要地质灾害时空特征,结果表明:①四川省主要地质灾害的活跃性呈周期变化,正常情况下呈现3 a左右的小周期,“5·12”地震后地质灾害逐年增强,4 a达到峰值,之后逐年减弱,8 a后其影响不明显;②主要地质灾害发生的相对强度地震后变化不大,但较震前在各类型分区所表现的地质灾害活力与强度不对应,地貌分区中地灾数量最多的为四川盆地,而地灾活力最强的为川西北高原;岩性分区上震后地灾易发性与震前相比较第四系高于坚硬岩区;构造分区上地质灾害具有明显的分区特征,地震前后扬子准地台发生的地灾强度均远远大于松潘-甘孜地槽褶皱系,但地灾活力明显弱于松潘-甘孜地槽褶皱系,基本构造单元也有类似的特点。
The temporal and spatial development law of regional geohazards is the result of the joint action of internal and external geological forces,which are relatively stable within a large area.Therefore,the source,magnitude and occurrence time of earthquakes are the main factors affecting the temporal and spatial development law of regional geohazards.In order to study the impact of"5·12"Wenchuan earthquake on the spatial and temporal development of geohazards in Sichuan Province,based on the data of landslide,collapse,debris flow,earthquake and rainfall from 1998 to 2018,the spatial and temporal characteristics of major geohazards in Sichuan Province around the Wenchuan earthquake were analyzed by mathematical statistics and spatial analysis methods,The results show that:①Activity in major disasters in Sichuan Province shows cycles,under normal circumstances,it presents a small cycle of about 3 years,after the earthquake geohazards increased year by year,to the peak of 4a,then decreased year by year;the impact is not obvious after 8 years;②The relative intensity of major geohazards has little change after the earthquake,but the activity and intensity of geohazards are not corresponding before the earthquake.In the geomorphic division,the largest number of geohazards is in Sichuan Basin,and the most active is in Northwest Sichuan Plateau.Compared with that before the earthquake,the occurrence of geohazards in the quaternary system is higher than that in the hard rock area.The geohazards in the tectonic zones have obvious zoning characteristics.The earthquake intensity of the Yangtze quasi-platform is much greater than that of the Songpan-Ganzi geosynclinal fold system before and after the earthquake,but the disaster activity is obviously weaker than that of the Songpan-Ganzi geosynclinal fold system,and the basic structural units have similar characteristics.
作者
文广超
苏林雪
谢洪波
陈红旗
徐招峰
Wen Guangchao;Su Linxue;Xie Hongbo;Chen Hongqi;Xu Zhaofeng(School of Resources and Environment,Henan Polytechnic University,Jiaozuo Henan 454000,China;China Geological Environment Monitoring Institute,Beijing 100081,China)
出处
《地质科技通报》
CAS
CSCD
北大核心
2021年第4期143-152,共10页
Bulletin of Geological Science and Technology
基金
九寨沟地震灾区生态化地质灾害防治重大科技支撑研究课题(KJ-2018-23)
河南理工大学博士基金(B2020-54)。
关键词
“5·12”汶川地震
地质灾害
时空发育
地灾强度
地灾活力
"5·12"Whenchuan earthquake
geohazards
temporal and spatial development
intensity of geohazards
activity of geohazards
