Abstract:

The earthquake secondary geological disasters refer to the geological disasters induced by earthquake,including mainly landslide,collapse,and also ground caving in and soil liquefaction,etc. The earthquake secondary geological disasters not only aggravate the earthquake losses,but also bring on difficulties in disaster relief and post-quake reconstruction. More than 20 provinces(municipalities and autonomous regions)in China have been subject to earthquake secondary geological disasters but with various degrees in different regions. The areas of Shaanxi,Gansu,Ningxia,Sichuan,Chongqing,Yunnan and Tibet in the central part of Chinese continent are the most seriously affected,forming a NNE-trending high danger zone. The geologic and geomorphic conditions for generating earthquake secondary disasters are basically the same with that of general geological disasters,but the trigger factor for the former is earthquake. Secondary geological disasters are likely to happen in areas of M≥5.0 and seismic intensity ≥Ⅵ,and the higher the earthquake magnitude and intensity,the more serious the secondary geological disasters. The damage caused by earthquake secondary geological disasters is similar compared with other geological disasters,but the chance of occurrence of the former is smaller.

Key words: earthquake, secondary geological disaster, distribution, formation condition

摘要：

地震次生地质灾害是指地震引起的崩塌、滑坡及塌陷、地裂缝、砂土液化。中国20多个省(市、自治区)都发生过地震次生地质灾害,但不同地区发育程度不一,以中国大陆中部的陕、甘、宁、川、渝、滇、藏地区最为严重,形成一个NNE向的高危险带。地震次生地质灾害形成的地质地貌条件与一般地质灾害基本相同,但其激发因素为地震。震级5级以上、烈度Ⅵ度以上的地区,可能引发次生地质灾害,震级和烈度越高,次生地质灾害越强烈。

关键词: 地震, 次生地质灾害, 分布, 形成条件