LANDSLIDE FACTOR SENSITIVITY ANALYSES FOR LANDSLIDES TRIGGERED BY 2013 LUSHAN EARTHQUAKE USING GIS PLATFORM AND CERTAINTY FACTOR METHOD

This paper uses GIS technology as the operating platform and adopts the certainty factor method to carry out a more detailed susceptibility analysis of the 2013 Lushan earthquake-triggered landslides. The analysis combines the basic situation of the earthquake zone and is based on the existing relevant factor data including topographic factors(elevation, slope angle, slope aspect, curvature),geological factors(lithology, distance from the deep active faults) and seismic factors(PGA,distance from the epicenter).Firstly, the eight seismic landslide impact factors are graded according to the characteristics of the study area with GIS technology as the platform. A different grading impact factor raster layer is built to complete the parameter statistics of seismic landslide distribution. The most sensitive grading interval is extracted for sensitivity analysis to measure the susceptibility sensitive degree of seismic landslide by different factors grading interval, which is from the value of certainty factor of eight seismic landslide impact factors. The sensitivity analysis of seismic landslide factor shows that the other six factors are very sensitive for landslide-prone and they are the main factors of terrain, geology and earthquake respectively except for curvature and the epicenter factor. The results that the curvature and the epicenter factor are not very sensitive for landslide-prone are further analyzed and discussed. The effect of the internal other factors is also analyzed. The SW aspect is likely to limit the sensitivity of curvature acting on seismic landslide-prone. The limiting is more obvious for lithology than the epicenter factor. Such limiting may not be applicable for the rock strata in Ordovician and Silurian. The results have a certain approach theoretical significance and a certain reference value for earthquake disaster reduction.