## 4 Analysis
### Scenario 1  
#### 4.3.1 The Landslide Susceptibility Results for Scenario 1  
We generated multiple datasets with different ratios of landslide to non-landslide samples (1:1, 1:5, 1:50, 1:100, 1:150, and 1:200), as shown in Table 5. The LSP results were then classified into five susceptibility levels (very high, high, medium, low, and very low) to generate LSMs (Figure 7). The results demonstrate that sample ratio variations significantly impact landslide susceptibility zoning. As the proportion of non-landslide samples increases, high and very high susceptibility zones gradually decrease, while low- and very low-susceptibility zones increase accordingly. This trend is most noticeable between the ratios of 1:1 and 1:50, after which it stabilizes. At a 1:1 ratio (Figure 7a),  
Figure 6: SHAP scatter plots for (**a**) NDVI and (**b**) altitude.  
high- and very high-susceptibility areas are more widely distributed, especially in the northern and northwestern regions. As the ratio increases (Figure 7b-f), high- and very high-susceptibility areas decrease significantly, reducing spatial differences in susceptibility levels, and the landslide susceptibility distribution becomes more uniform, concentrating mainly in low- and very low-susceptibility zones. Moreover, even at high ratios (e.g., 1:200), some medium- and high-susceptibility areas remain in the northern and eastern edges of the study area, which generally aligns with the observed landslide sample distribution.  
As shown in Figure 8, increasing the proportion of non-landslide samples leads to a gradual reduction in the mean and standard deviation of the LSIs. At a 1:1 ratio (Figure 8a), the mean LSI is 0.301, with a standard deviation 0.256. While low-susceptibility areas dominate, there is still a notable presence of medium-to-high-susceptibility areas. At ratios of 1:5 (Figure 8b) and 1:50 (Figure 8c), the mean decreases to 0.132 and 0.028, respectively, along with corresponding reductions in standard deviation, and there is a significant contraction in the high-susceptibility range. As the non-landslide sample ratio further increases to 1:100, 1:150, and 1:200 (Figure 8d-f), the mean drops to 0.016, 0.012, and 0.009, respectively, and the standard deviation continues to decrease, with the LSIs becoming increasingly concentrated in low-susceptibility areas. When the ratio increases from 1:1 to 1:50, the mean and standard deviation of the LSIs exhibit significant reductions and substantial fluctuations. However, as the ratio rises to 1:100 and beyond, these values stabilize, with predictions being increasingly focused on very low- and low-susceptibility zones. The growing proportion of non-landslide samples reduces the spatial  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Landslide/Non-** & \multirow{2}{*}{**Landslide Slope Units**} & **Non-Landslide** & **Total Number of Landslide and** & \multirow{2}{*}{**Training Set (70\%)**} & \multirow{2}{*}{**Test Set (30\%)**} \\
**Landslide** & & **Slope Units** & & **Non-Landslide Slope Units** & \\ \hline
1:1 & 589 & 589 & 1178 & 824 & 353 \\
1:5 & 589 & 2945 & 3534 & 2474 & 1061 \\
1:50 & 589 & 29,450 & 30,039 & 21,027 & 9012 \\
1:100 & 589 & 58,900 & 59,489 & 41,642 & 17,847 \\
1:150 & 589 & 88,350 & 88,939 & 62,257 & 26,682 \\
1:200 & 589 & 117,800 & 118,389 & 82,872 & 35,517 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Distribution of landslide and non-landslide samples in Scenario 1.  
Figure 7: Landslide susceptibility maps with different imbalanced ratios in Scenario 1.  
heterogeneity of LSPs, concentrating susceptibility indices primarily in very low- and low-susceptibility areas.