Table 1 Improved tangent angle criteria for landslide warning levels
From: 5G IoT-based geohazard monitoring and early warning system and its application
Deformation stage | Uniform velocity deformation stage | Early acceleration stage | Mid-acceleration stage | Critical sliding stage |
|---|---|---|---|---|
Early warning level | Attention | Caution | Warning | Danger |
Warning form | Blue alert | Yellow alert | Orange alert | Red alert |
Angle of incidence | \(\alpha \approx 45^\circ\) | \(45^{^\circ } < \alpha < 80^{^\circ }\) | \(80^{^\circ } \le \alpha < 85^{^\circ }\) | \(\alpha \ge 85^{^\circ }\) |