The Characteristics of Geological Disasters Triggered by Wenchuan Ms8.0 Earthquake in Wudu District and Wenxian County of Gansu Province

The strong effect on ground damage and the serious earthquake-induced geological disasters are notable features of MS8.0 Wenchuan earthquake. This study obtained 993 earthquake geological disasters in Wudu District and Wenxian County of Gansu Province, by combining field investigation and interpretation of remote-sensing images. Then the characteristics of these geological disasters were investigated statistically using GIS techniques to determine how the occurrence of geological disasters correlated with intensity, distance from the rivers, slopes and elevations. The main results can be summarized as follows: (1) the geological disasters density increased with the increase of earthquake intensity; (2) the geological disasters triggered by earthquake show the feature of zonal distribution along the rivers; (3) the slope steepness is the main factor which controls the development of earthquake-induced geological disasters and most of the geological disasters are distributed with the slopes of 10 to 40 degree; (4) the earthquake-induced geological disasters have corresponding relationships with elevations, and most disasters occur with the elevation of 1000 to 2000 m.