Risk Assessment of Debris Flow in the Kashgar-to-Khunjerab Section of the China–Pakistan Economic Corridor

The risk of debris flow comprehensively reflects both the natural and social attributes of debris flow disasters, composed of the hazard of debris flow and the vulnerability of the bearing body. The geological environment of the Kashgar-to-Khunjerab section of the China–Pakistan Economic Corridor is complex, with widespread debris flow disasters, strong activity, and severe hazards, posing a significant threat to corridor construction and public safety. Therefore, conducting debris flow risk assessments in the Kashgar-to-Khunjerab section of the China–Pakistan Economic Corridor has great significance for disaster prevention and control. Based on field investigation data of debris flows, this study evaluates the hazard of debris flows in the study area through the frequency ratio and frequency ratio–logistic regression coupled models. The vulnerability of debris flows was evaluated through a contribution weight model. Based on the assessment results of hazard and vulnerability, a risk assessment model was utilized to explore the risk situation of debris flow disasters in the Kashgar-to-Khunjerab section of the China–Pakistan Economic Corridor. The results show that the frequency ratio–logistic regression coupled model (AUC = 0.867) is more suitable for debris flow disasters hazard assessment. The area of medium hazard zones and above accounts for 68.6% of the total area. The vulnerability in the study area is generally concentrated in the township regions along the Kashgar-to-Khunjerab section of the China–Pakistan Highway. The proportion of medium and above vulnerability zones areas reaches 55.6%. The risk levels of the study area generally radiate outward from the Kashgar-to-Khunjerab section of the China–Pakistan Highway, exhibiting a decreasing trend of from high to low. The distribution areas of different risk zones initially increase and then decrease with the rise in risk levels, and the area of medium risk zones and above accounts for 50.8% of the total area. Approximately 91.7% of debris flow disaster points are located in high and very high risk zones. This indicates that the study area has a high level of risk. The study results can provide a scientific basis for planning debris flow disasters prevention and mitigation measures, and the proposed assessment methods can also serve as a reference and guidance for debris flow risk assessment in the study area and other regions.