Risk assessment of geo-hazard of China in county unit

In this paper, geo-hazards include landslide, collapse, debris flow and ground collapse. By calculating the risk of geo-hazard and vulnerability of hazard-affected bodies separately, we evaluated the geo-hazard risk of county territory unit by qualitative comprehensive assessment. First, we separated the vulnerability of hazard-affected bodies into population safety vulnerability and property vulnerability, then we use the rate of dead population and rate of direct economic loss that caused by geo-hazard as representation as index. Based on historical data analysis guiding the future prediction, combing with the database of geo-hazard situation during 2001—2005 from Ministry of Land and Resources, we proposed the grading standard of population safety vulnerability and property vulnerability. Based on the geological hazard risk evaluation from the 2869 county territory units, 216 units are in the high-risk, 643 units are in middle-risk and 2010 are in low-risk. The high-risk areas are dominated in Wumeng mountainous, Mountainous around Sichuan Basin, Western Yunnan and Southeast part of Tibet.