Research on the risk assessment method of geological hazards in town (street) ：A case study of Chengguan Town, Shiquan County of Ankang

Background Geological hazard risk refers to the possibility and severity of losses suffered by the disaster bearing body due to geological hazards in a certain area and period. At present, there is a wide range of research on the risk of regional geological hazards, and there are many types of evaluation methods and models applied. In order to explore an effective geological hazard risk evaluation method suitable for township (street) regional scale, this study selects Chengguan Town in Shiquan County, Shaanxi Province, which has a high incidence of geological hazards and hidden dangers, as an example. Methods A full process method for geological hazard risk assessment was proposed, which integrates multiple conditional models and takes slopes as the evaluation unit. The method is based on the comprehensive index method to evaluate susceptibility, the extreme rainfall assumption model, effective rainfall model, and slope unit stability model to evaluate hazard, the weighted sum method of quantitative indicators of the disaster bearing body to evaluate vulnerability, and the comprehensive hazard and vulnerability evaluation method to evaluate risk. Results The research results indicate that the geological hazard susceptibility evaluated based on this method can effectively reveal the geological background characteristics of the disaster prone area. The geological hazard risk can reflect the differences in the degree of geological hazard damage suffered by the area under different rainfall conditions, as well as the spatial differences in regional risk under a certain rainfall condition. The vulnerability of the geological hazard bearing body can quantitatively reflect the loss value of the bearing body after being affected by geological hazards. The final geological hazard risk can accurately classify areas with higher geological hazard risk levels. Conclusions In summary, the risk assessment method based on slope units proposed in this study can provide a clear and reliable method basis for the risk assessment of regional geological disasters at the township (street) scale, and provide technical support for effective prevention and control of regional geological disasters.