## 4 Results
The landslide quantity and scale are positively related to the magnitude (peak ground acceleration (\(a\))) of the earthquake and represent an inflection point where the area of the hazard zone increases sharply, which can be deduced via statistical analysis of the correlation of regional historical seismic landslides, such as the 2008 \(M_{w}\) 7.9 Wenchuan earthquake and the 2013 \(M_{s}\) 7.0 Lushan earthquake. The point is the critical value for a large regional disaster in which the landslide hazard is ruinous for the region once the magnitude (peak ground acceleration (\(a\))) approaches or reaches it. A power function linear curve was obtained by analyzing the correlation of the distributions of the high- and medium-hazard zones with different peak ground accelerations (a), as shown in Table 3. In this case, the correlation coefficient R\({}^{2}\) = 0.995 of the high-hazard zones and the correlation coefficient R\({}^{2}\) = 0.995 of the medium-hazard zones, with the peak ground acceleration (\(a\)), are well correlated. The area of the hazard zone sharply increases at a peak ground acceleration \(a\) = 0.3, which can be regarded as the critical point for a regionally destructive disaster. Figure 8: Probability of seismic landslide assessment via the information value model. \begin{table}
\begin{tabular}{c c c c} \hline \multirow{2}{*}{**Condition**} & \multicolumn{2}{c}{**Distribution Area/km\({}^{2}\)**} & \multirow{2}{*}{**Control Factors**} \\ \cline{2-2} \cline{4-4}  & **High Hazard** & & **Medium Hazard** \\ \hline a = 0.1 & 2.78 & 4.01 & Landslide inventory \\ a = 0.2 & 3.42 & 6.29 & The rock properties and \\  & & & landslide inventory \\ a = 0.3 & 6.78 & 10.02 & Slope and rock properties \\ a = 0.4 & 11.62 & 13.28 & Slope \\ \hline \end{tabular}
\end{table} 
Table 3: Areas of high- and medium-hazard zones under different working conditions. * When a = 0.1  the area of the high-hazard zone is 2.78 km\({}^{2}\), accounting for 11.49% of the research region, and the area of the medium-hazard zone is 4.01 km\({}^{2}\), accounting for 16.57% of the research region. The hazard zone is distributed mainly from river valleys to steep slopes in the mountainous region and is significantly affected by a single landslide. The distribution of hazard zones is highly correlated with the landslide inventory. * When a = 0.2  the area of the high-hazard zone is 3.42 km\({}^{2}\), accounting for 17.02% of the research region, and the area of the medium-hazard zone is 6.29 km\({}^{2}\), accounting for 25.99% of the research region. The area of the hazard zone increased significantly, with a growth rate of 48.02% compared with \(a\) = 0.1 g. The distribution characteristics of the high-hazard zone rapidly increases along the topographic features of the river valley, with a zonal distribution  
Figure 9: Seismic landslide zoning maps at different peak ground accelerations (_a_): (**a**) when a = 0.1; (**b**) when a = 0.2; (**c**) when a = 0.3; (**d**) when a = 0.4.  
in the steep slope area in many regions, and the distribution is significantly controlled by the rock properties and landslide inventory in the high-altitude area at a grade of \(a=0.2\). * When a = 0.3
* the area of the high-hazard zone is 6.78 km\({}^{2}\), accounting for 28.05%, and the area of the medium-hazard zone is 10.02 km\({}^{2}\), accounting for 41.40% of the research region. The area of the hazard zone increases significantly, with a growth rate of 64.56% in comparison with a grade of \(a=0.2\) g. The distribution characteristics clearly reveal that the hazard zone spread to surrounding areas along the slope in multiple regions on the bases of the controlling factors, i.e., the slope and rock properties. * When a = 0.4
* the area of the high-hazard zone is 11.62 km\({}^{2}\), accounting for 48.03%, and the area of the medium-hazard zone is 13.28 km\({}^{2}\), accounting for 59.01% of the research region. Compared with \(a=0.3\) g, the area of the hazard zone increases significantly, with a growth rate of 71.38%.