Risk assessment and response for personnel loss caused by debris flow disasters considering non-engineering disaster mitigation measures

Debris flow disasters in mountainous areas threaten the lives, property, and life of residents. Effective disaster reduction strategies are needed to reduce this potential risk. Through a comprehensive literature review and on-site inspections, this study identifies 16 factors impacting the risk of personnel loss. Subsequently, a risk assessment and response analysis model is developed utilizing Bayesian network (BN). The model includes debris flow risk assessment and personnel disaster resistance evaluation. By utilizing the expected maximum (EM) algorithm to analyze historical disaster data of Ya’an City over the past few years, model parameters for DFR assessment are derived. Additionally, quantitative standards for non-engineering measures are established and the Analytic Hierarchy Process is employed to obtain model parameters for PDR evaluation. Finally, these two components of the model are integrated and applied to a watershed within Ya’an City. The results of this application indicate that strengthening the construction of early warning systems in that watershed can effectively reduce the risk of personnel loss. The model is expected to provide a more scientific and comprehensive reference for debris flow risk assessment and response.