Distribution rules of geo-hazards induced by Wenchuan Earthquake

Wenchuan Earthquake causes a large number of geo-hazards in Wudu District and Wenxian County of Gansu Province. After a field investigation and the interpretation of remote-sensing images taken after the earthquake ， 993 earthquake-induced geo-hazards are obtained. Then, the distribution of these geo-hazards is investigated statistically using GIS techniques to determine how the occurrence of geo-hazards correlates with distance from the rivers, slopes, elevations and aspect s. The main results of this research can be summarized as follows: (1) the geo-hazards triggered by earthquake show the feature of zonal distribution along the rivers; (2) the geo-hazards density increases with the increase of earth intensity; (3) the earthquake-induced geo-hazards have corresponding relationship with the elevation, and for most hazards occur below the elevation of 1000 to 2000 m; (4) the slope steepness is a main factor which controls the development of earthquake-induced geo-hazards and a vast majority of geo-hazards are distributed within the range of 10 ° to 40 ° ; (5) aspect influences on the geo-hazards triggered by the Earthquake, and more hazards occur in aspect of due south and southeast.