2014年鲁甸M_S6.5地震后地质灾害发育分布特征

Development and Distribution Characteristics of Geological Hazards after the 2014 Ludian M_S6.5 Earthquake

2014年云南鲁甸"8·03"M_S6.5地震造成了重大人员伤亡和财产损失,诱发了大量滑坡、崩塌、泥石流等地质灾害。基于对鲁甸县龙头山幅(G48E006006)地质灾害调查数据和对典型地质灾害的剖析,震后地质灾害发育分布有特征如下:(1)震后地质灾害较震前成倍增长,震前地质灾害多以中小型浅层崩滑为主,地震诱发了诸如甘家寨、红石岩等大型—特大型滑坡、崩塌,大量沟谷崩滑堆积物为泥石流储备了丰富的物源;(2)震中高烈度区域地质灾害密度大,沿发震断裂带NNE-NE向构造密集发育,震中区龙头山镇地质灾害发育最为集中;(3)地质灾害呈带状分布,明显受控于河流水系(牛栏江、沙坝河、龙泉河等)、公路(昭巧二级公路、沙乐公路)等线性地貌单元和线性工程,人类活动影响明显。

The Ludian M S6.5 earthquake on August third,2014,caused heavy casualties and property losses and induced a large number of landslides,collapses,and secondary geological disasters.Based on a geological disaster survey of Longtoushan map(G48E006006)in Ludian County and analysis of typical geological disasters,development laws and distribution characteristics of geological hazards after the earthquake are revealed in this paper:(1)Most of the geological disasters before the earthquake are mainly medium and small shallow landslides and collapses.After the earthquake,large and extra\|large landslides and collapses were induced,such as Ganjiazhai and Hongshiyan,and a large number of valley deposits were formed;(2)The distribution of geological disasters is concentrated in high\|intensity areas of epicentral region,especially in Longtoushan town and intensively developed along the NNE\|NE trending seismogenic fault zone,the geological disasters develop most intensively in epicentral area;(3)The geological disasters show a zonal distribution feature,obviously controlled by linear geomorphic units and linear engineering,such as river systems(Niulan River,Shaba River,and Longquan River)and highways(Zhaoqiao road and Shale road),and the impact of human activity is striking.