Threshold Analysis of Rainfall Induced Geological Hazards on Highways in Hunan Province

In order to understand the factors and thresholds of geological disasters induced by rainfall on highways in Hunan Province, and effectively improve the meteorological service capabilities of highway transportation, based on the distribution data of 148 rainfall induced geological hazards (mudslides, landslides, and collapses) along highways in Hunan Province, as well as 11 environmental variables including meteorology, topography, and vegetation coverage, the maximum entropy model (MaxEnt) and GIS technology were used to simulate the distribution areas and changes of geological hazards. The results showed that: (1) the MaxEnt model had high simulation accuracy, with AUC values ranging from 0.821 to 0.841; TSS is 0.813. (2) The five key environmental factors that affect geological hazards are 24-hour cumulative precipitation, 72 hour cumulative precipitation, 120 hour cumulative precipitation, and hourly maximum precipitation DEM. The thresholds with a probability of occurrence exceeding 70% are 65mm, 190mm, 230mm, 55mm, and 50-450m, respectively. (3) The geological hazard prone areas along Hunan highways are mainly distributed in Zhangjiajie G5513, Huaihua G65 G60, Shaoyang G356, Chenzhou S31 G04, Loudi G55 S71, along the Yueyang G56 and other routes. This study can provide reference for meteorological warning and prevention of geological disasters on highways, and has significant theoretical value and practical application significance.