2014年云南鲁甸地震触发地质灾害发育分布规律及与景谷、盈江地震对比研究

The Development and Distribution Characteristics of Geohazards Induced by August 3,2014 Ludian Earthquake and Comparison with Jinggu and Yingjiang Earthquakes

2014年8月3日16时30分,云南省鲁甸县龙头山镇Ms6.5级地震造成617人死亡,触发1700多处崩塌滑坡等地质灾害点,同年,该省又发生了Ms6.6级景谷地震和Ms6.1级盈江地震。笔者在对鲁甸等3次地震区次生地质灾害现场调查和遥感解译的基础上,研究了鲁甸地震触发地质灾害的发育分布规律,首次提出了地震"干滑坡"的概念,并从震级、地形地貌、活动构造、人口密度等多个方面对比了鲁甸地震、景谷地震和盈江地震触发地质灾害的异同点。主要结论有:1鲁甸地震后新增地质灾害数量显著增加,其主要分布在水系的深切峡谷区,表现为"干滑坡"特征;2大型、特大型崩塌滑坡灾害点主要受活动断裂控制;3地震地质灾害的发育特征与地貌高程和微地貌具有很好的响应关系;4鲁甸震区的地形坡度明显大于景谷和盈江震区,地形坡度是鲁甸地震区地质灾害发育的主要控制因素;5我国西南高山峡谷区的断层、河流、阶地和城镇是相互依存,不可分割的地质环境载体,震后房屋选址、重建规划不仅要注意房屋抗震问题,还应充分考虑地质环境安全问题。

At 16：30on August 3,2014,an Ms 6.5earthquake struck Ludian County（27.1°N,103.3°E）,Zhaotong,in Yunnan Province,resulting in a death toll of 617 and more than 1700 geohazards including collapsing and landsliding.In the same year,two earthquakes,Ms 6.6Jinggu earthquake and Ms 6.1Yingjiang earthquake,occurred in this province.Authors,on the basis of in site investigation of geohazards and interpretation of remote sensing images,studied the development and distribution of geohazards triggered by the Ludian earthquakes,and propose a concept of Dry Landslide for the first time.At the same time,the geohazards triggered by Ludian,Jinggu and Yingjiang earthquakes were discussed in terms of geohazards and magnitude,geomorphology,structural activity,slope angle,seismic intensity and population density.Main conclusions are as follows：① the number of geohazards increased significantly after the Ludian earthquake,which are distributed mainly in the deep valley areas;② main large-scale landslides are controlled by active faults; ③ good response relationships between the geohazareds topographic elevation and micro-topography;④ the topographic slopes of Ludian earthquake area are significantly greater than that of the Jinggu and Yingjiang earthquake areas,and the topographic slopes are the key triggering factors of geohazards in the Ludian earthquake area;⑤ the mountains and canyons,rivers,terraces and towns are interdependent in southwestern China,therefore,post-earthquake reconstruction planning should take not only seismic issues but geohazards prevention and geological environment safety into consideration.