Study on Risk Assessment of Mountain Flood Disaster in Nanling National Park

The Nanling National Park is located in the mountainous area of northern Guangdong Province. Flash flood disasters occur frequently and cause serious casualties and property losses, presenting a severe challenge to disaster prevention and mitigation in the national park. According to the characteristics of flash flood disasters in the Nanling National Park, based on triggering disaster-causing factors and disaster-pregnant environments, eight indicators such as total rainfall, rainstorms days, terrain slope, relative height difference, watershed shape, and river network density are selected to construct a hazard assessment index system for flash flood disasters. The AHP method is used to determine the weights of each factor and its classification, and flash flood disaster survey data is applied to verify the evaluation results. The results show that the flash flood disaster hazard index of the Nanling National Park is between 0.059 and 0.477, and the evaluation results are consistent with the survey results of field investigation. The area above medium hazard is about 1216.9 km2, accounting for nearly 63% of the total area. Among them, the area of high-hazard zones is about 217.52 km2, accounting for 11.25%, which is mainly distributed in the areas of Shigutang Town, Hengshitang Town, and Yinghong Town in the south of the national park, the western part of Guangdong Tianjingshan Forest Farm, Chengjia Township, Dabu Town, Xingzi Town and Longping Town in Lianzhou, Qingyuan and other partial areas. It is necessary to strengthen community-based and professional monitoring of flash flood disasters, enhance the monitoring and early warning system, and improve the scientific prediction and forecasting of flash flood disasters to avoid major losses.