【摘要】 地震触发地质灾害主控因素的厘定是研究地震地质灾害和灾后应急救援响应的关键问题。笔者在野外典型地震滑坡实地调查和室内图件分析的基础上,以2008年以来我国先后发生的汶川地震、玉树地震、芦山地震、岷县漳县地震和彝良地震触发的地质灾害为研究对象,开展了地震地质灾害主控因素研究,主要取得以下认识:(1)地震地质灾害的空间展布特征主要受控于发震断裂的活动性质、地震动峰值加速度(PGA)、震区地形坡度和高差、距断裂带和水系的距离等4个方面。地震型地质灾害主要沿地震断裂带呈带状分布,逆冲型地震较走滑型地震诱发的高位、高速远程滑坡数量多,方量大,危害严重。(2)地震震级越大,极震区地形坡度越陡,地层风化破碎越严重,发生地质灾害的可能性就越大,造成的危害也更加严重,如2008年5·12汶川地震区。(3)地震地质灾害分布与地震烈度等级大小无必然联系,部分低烈度区因处于高山峡谷区而灾害频发。因此,震后地质灾害排查要充分利用地震地质灾害的成灾模式和成灾规律,震中区和地震高烈度区不一定是地质灾害极易发区。地震型地质灾害主控因素的分析为震后地质灾害空间分布范围预测及为灾后减灾应急响应方案制定提供了技术支撑。更多还原

【Abstract】 On the basis of surveying and mapping of some typical geo-hazards induced by Wenchuan,Lushan,Yushu,Minxian,and Yiliang earthquakes that happened in western China since 2008,the key controlling factors of geo-hazards induced by earthquake are studied in the paper.Some main conclusions are as follows:(1)the spatial distribution of geo-hazards induced by earthquake was mainly controlled by four factors,i.e.,the active nature of the seismogenic fault,the peak ground acceleration(PGA),the geomorphological slope and elevation of the seismic area,and the distance from the seismogenic faults and rivers.The geo-hazards induced by earthquake were distributed along the fault and exhibited in the shape of bands;the impact of high-speed remote landslides occurring on a high position with mass volume was more severe;(2)the greater magnitude of earthquake,the steeper geomorphological slope,and the heavily broken and weathering strata will more probably cause severe geo-hazards,such as the Wenchuan earthquake area;(3)there is no inevitable relationship between the spatial distribution characteristics and the level of seismic intensity.Some mountains and canyons are often hazard-prone areas because of the highly geomorphological enlarger effects.Therefore,the forming patterns and mechanisms of geo-hazards induced by earthquake were fully utilized in the survey of the geo-hazards after earthquake,and the epicenter and high intensity seismic zones are not often necessarily the hazard-prone areas.The results of this paper may be used to predict the spatial distribution areas of geo-hazards induced by earthquake,and provide some technical supports for emergency response.更多还原