Susceptibility Forecast of Geo-Hazard under the Conditions of Earthquake and Rainfall

Large amount of loose deposits and potential geo-hazards were formed by Wenchuan earthquake , which would be transformed into collapses, landslide and debris flows under the condition of rainfall or aftershock. The paper divides influence factors into triggering factors and background factors, and constitutes susceptibility forecast system for geo-hazard based on factors in parallel or series. The background system contains stratum, distance to river, relief, slope and aspect of slope. And the triggering system includes distance to seismic fault and rainfall . The paper applies and verifies the system to forecast the susceptibility of geo-hazard in study area, and the result shows that 52 small watersheds are in extremely high and high states accounting for 37.68% in 138 small watersheds. According to the statistics of 23 geo-hazards from field investigation, 13 geo-hazards are in extremely high risk grade of susceptibility and 10 geo-hazards are in high risk grade of susceptibility , which shows that the result of susceptibility forecast of geo-hazard is reasonable. © (2013) Trans Tech Publications, Switzerland.