“4·20”芦山地震崩塌滑坡与公路危险性评价——以宝兴县省道S210沿线为例

The Ms 7． 0 April 20，2013 Lushan earthquake induced more than 1 460 landslides and collapses in Sichuan of China． Ｒoads were blocked by the landslides and collapses，so the relief people and machineries could not go into the earthquake-stricken area immediately，and the relief works were delayed in some degree． The highway S210，which was an important line of communications connect Baoxing and Lushan，was taken as study area． The aerial images with 0． 5 m spatial resolution were used to interpret the landslides and collapses induced by the earthquake． Then characteristics of distribution were analyzed base on topographical factors，geological factors and distance to the epicenter． The susceptibility assessment was conduct by Certainty Factor and Frequency Ｒatio method． At last，the hazard assessment to the road were done base on the susceptibility map． Some conclusions were got that，the collapse was the main hazard induced by the earthquake along the S210 highway; they were concentrated in the elevation of 750 m to 1 500 m，and the slope gradient of landslides and collapses mainly between 30° to 60°． Large numbers of landslides and collapses occurred in the aspect of west，southwest and northwest slopes． The lithology also influenced the distribution of landslides and collapses，most of landslides and collapses located in the hard rocks or hard and soft alternated rocks． Many landslides and collapses located in the area with distance of 19 km to 21 km to the epicenter． Form the susceptibility may of landslides induced by the earthquake，the very high and high susceptible zones located in the north part and north part of the highway，and the low and very low susceptible zones located in the middle of the highway．