Assessment of post-earthquake secondary geological hazard risk based on GIS

The strong effect of ground damage and the serious earthquake-induced geological disasters are the notable features of Wenchuan earthquake. The distribution of earthquake-induced geological disasters in the earthquake is closely related to the distribution of earthquake fault, at the same time, it´s also influenced and controlled by the physical geography, lithology, geological structure and human activities. The paper systematically generalizes the development characteristics, formation conditions and inducing factors of geological disasters combining with analysis of site conditions in Beichuan County. Analysis of correlative character between secondary geological disasters and the factor, and use information value method to evaluate the hazard of secondary geological disasters. The hazard map was obtained by summing up all geographical corresponding pixel values from each spatial layers according to information value. So geographical information systems combined with information value model can be quickly and effectively evaluate the spatial distribution and hazard of secondary geological disasters.