摘要:2014年8月3日云南鲁甸地震诱发了大量次生地质灾害,研究表明此次地震小震大灾的原因是前期干旱导致土体强度降低,在暴雨作用下引发大量次生灾害。在小震大灾的岩土性质基础上,通过分析地形地貌、地质条件、地震活动和极端干湿气候对地质灾害发育的影响,建立地质灾害易发性评价指标,利用GIS空间分析技术对震后灾区泥石流易发性进行了快速定量评价。结果显示,地震灾区地质灾害高、中、低易发区面积分别为6 865.87km~2、 15 102.72km~2、9 869.06km~2。其中高易发区主要集中于金沙江与牛栏江沿线,呈带状分布,以及受地层岩性的影响呈岛状等不均匀分布,今后在进一步的极端气候影响下,区域泥石流灾害有可能进一步发展。

A large number of secondary geological disasters occurred during the 8·3Ludian earthquake of Yunnan Province.The disaster is resulted from the falling of soil strength duo to predrought and rainstorms.For assessment of secondary geological hazards,the effects of topography, geological conditions,earthquake and drought on debris flow development are analyzed,and the assessment indexes are established.A speedy quantitative assessment of hazards sensibility is exercised by using GIS spatial analysis technology.It indicates that the high probable,mid-probable, low probable geological disasters are 6865.84km~2,15102.72km~2,9896.06km~2,respectively,and the high probable geological disasters distribute along the Jinsha River and Niulanjiang River.In the future,high probability of the debris flow hazard development exists under the condition of extreme climate influence.