Refinded hazard assessment and regionalization of snow disaster in Anhui Province

Based on the technical specifications for the national comprehensive risk survey of meteorological disasters, and in view of the characteristics of snow disaster impacts in Anhui Province, the observation element of snow pressure is considered and combined with other disaster causative factors, such as the annual maximum snow depth and annual average snow-covered days to establish a risk assessment model. Using the data of snow depth, snow pressure, and geographic information from 81 national meteorological observation stations in Anhui Province from 1978 to 2020, the spatiotemporal distribution characteristics of various disaster-causing factors are analyzed, and the terrain correction for snow-covered days is performed to obtain a refined assessment of snow disaster risk in Anhui Province. The results are as follows. The annual variation and differences of the average maximum snow depth, average snow-covered days, and maximum snow pressure are significant, but the top three years for all these factors are 2008, 1984, and 2018. The areas with high annual maximum snow depth are mainly concentrated between the Dabie Mountains, the southern Anhui Mountains, and the regions between the Yangtze River and the Huai River. Considering the significant correlation between the annual snow-covered days and elevation in the area above 100 meters and the appropriate sample size, after terrain correction, the high-value areas of snow-covered days are located in the Dabie Mountains and the southern Anhui Mountains, followed by the northwest of Huaibei to the northern foothills of Dabie Mountains. After interpolation calculation of missing measurements, the maximum snow pressure in Xuancheng, Tongling, northern Mount Huangshan, and other places is increased, with distinct localized characteristics. The high-risk areas caused by snow disasters in Anhui Province are mainly located in high-altitude regions such as the Dabie Mountains and the mountainous areas in southern Anhui, while the low-risk areas are mainly located in the eastern part of the Huaibei region, the eastern part of the region between the Yangtze River and Huai River, and the southwestern part along the Yangtze River.