## 5 Results
### Risk Assessment Under Different Rainfall Conditions  
Based on the slope unit classification, the average hazard index for each slope unit was calculated using ArcGIS spatial statistics. This value was then assigned to the corresponding slope unit attribute table. Using the natural break method combined with field survey data, the hazard index for each slope unit was divided into four levels: extremely high hazard zone, high hazard zone, moderate hazard zone, and low hazard zone. The slope units with the same hazard level were then merged, subdivided, and numbered, generating the hazard zoning maps for Huangshi Town under different rainfall conditions (Figure 9). (1) Hazard Assessment Under 24-h 100 mm Rainfall Condition: Using the geological hazard risk assessment method for the key investigation area, a geological hazard risk zoning map under the 24-h 100 mm rainfall condition was generated for the key investigation area. The key investigation area includes 64 slope units, with a total area of 1.596 km\({}^{2}\), and a total of 76 geological hazard risk points. Among these, the high-risk area contains  
Figure 8: The spatial distribution map of the instability probability of geological disasters in Huangshi Town (**a**) Under the 24-h 100 mm rainfall condition. (**b**) Under the 24-h 125 mm rainfall condition. (**c**) Under the 72-h 240 mm rainfall condition. Figure 9: Geological disaster risk zonation map of Huangshi Town. (**a**) Under the 24-h 100 mm rainfall condition. (**b**) Under the 24-h 125 mm rainfall condition. (**c**) Under the 72-h 240 mm rainfall condition. 22 slope units, covering an area of 0.556 km\({}^{2}\), which accounts for 34.86% of the total area of slope units in the key investigation area. There are 38 geological hazard risk points in this area. The medium-risk area contains 33 slope units, covering an area of 0.828 km\({}^{2}\), which accounts for 51.88% of the total area of slope units. There are 38 geological hazard risk points in this area. The low-risk area contains 9 slope units, covering an area of 0.212 km\({}^{2}\), which accounts for 13.27% of the total area of slope units. There are no geological hazard risk points in this area. (2) Hazard Assessment Under 24-h 250 mm Rainfall Condition: For the key survey area containing 64 slope units and a total area of 1.596 km\({}^{2}\), with 76 geological hazard risk points. Extremely High Hazard Zone: 33 slope units, covering 0.884 km\({}^{2}\), accounting for 55.36% of the total area. There are 49 geological hazard risk points. High Hazard Zone: 28 slope units, covering 0.653 km\({}^{2}\), accounting for 40.90% of the total area. There are 26 geological hazard risk points. Moderate Hazard Zone: 2 slope units, covering 0.034 km\({}^{2}\), accounting for 2.14% of the total area. There is 1 geological hazard risk point. Low Hazard Zone: 1 slope unit, covering 0.026 km\({}^{2}\), accounting for 1.61% of the total area. No geological hazard risk points are identified. (3) Hazard Assessment Under 72-h 240 mm Effective Rainfall Condition: For the key survey area containing 64 slope units and a total area of 1.596 km\({}^{2}\), with 76 geological hazard risk points. Extremely High Hazard Zone: 33 slope units, covering 0.884 km\({}^{2}\), accounting for 55.36% of the total area. There are 49 geological hazard risk points. High Hazard Zone: 28 slope units, covering 0.653 km\({}^{2}\), accounting for 40.90% of the total area. There are 26 geological hazard risk points. Moderate Hazard Zone: 2 slope units, covering 0.034 km\({}^{2}\), accounting for 2.14% of the total area. There is 1 geological hazard risk point. Low Hazard Zone: 1 slope unit, covering 0.026 km\({}^{2}\), accounting for 1.61% of the total area. No geological hazard risk points are identified. These evaluations provide a clear risk classification based on different rainfall scenarios, supporting the effective mitigation and planning for geological hazard management in Huangshi Town.