## 4 Analysis and Discussion
### Discussion  
The Luding 6.8 earthquake was employed as a case study here, and both the difference method and the cumulative displacement method based on the Newmark model were used to evaluate the risk of earthquake-triggered landslides and conduct a comparative analysis.  
The validation results showed that both evaluation methods had high reliability, with the difference method slightly outperforming the cumulative displacement method. Unlike the complex cumulative displacement fitting formula, the difference method directly performed the difference operation between the \(PGA\) and \(A_{c}\). As a result, the assessment  
Figure 10: ROC curve of two earthquake-triggered landslide assessment methods.  
Figure 9: Actual landslides and non-landslide samples.  
results obtained with this method not only reflected the characteristics of the seismic landslide susceptibility of rock-soil masses but also captured the distribution and attenuation of the _PGA_. The difference method has been demonstrated to have effective performance in the study of earthquake landslides across numerous earthquake cases [24; 26; 32; 48; 49].  
Nevertheless, it is important to note that the natural breaks method, which forms the basis of the difference method for classifying the risk level of earthquake-triggered landslides, lacks clear physical significance in its natural break values [26; 48; 49]. Consequently, different sample data may result in varying breakpoints, potentially leading to the classification of the same risk level with different thresholds in distinct earthquake case studies, thus potentially impacting the assessment results.  
The cumulative displacement method employs empirical formulas to calculate the permanent cumulative displacement values of rock-soil masses for assessing earthquake-triggered landslide risk. This method not only facilitates a rapid evaluation of such risks but also enables predictions regarding potential loosening points induced by earthquakes within the rock-soil masses. It is crucial to bear in mind that the regional applicability of the empirical formula utilized to calculate the permanent cumulative displacement must be considered when employing this method [35; 36; 52]. Selecting an appropriate empirical formula tailored to the specific study area is imperative to avoid potential deviations in the assessment results.  
In conclusion, the regional earthquake-triggered landslide risk assessment technology based on the Newmark method has significantly advanced from its initial stage; however, there are still numerous shortcomings that require urgent improvement. Regarding the difference method, it is imperative to determine threshold values for each landslide risk interval having clear physical significance through the study of previous significant earthquake data. This approach will ensure that the assessment results not only receive verification-level support but also possess a solid theoretical foundation. As for the cumulative displacement method, establishing a fitting formula with a high regression coefficient between ground motion and cumulative displacement in each earthquake-prone area is crucial. Furthermore, improving the Newmark method itself entails establishing a more refined database of physical and mechanical parameters for rock-soil masses, along with regular updates of high-precision terrain data [18; 25; 52; 53]. These measures will contribute to enhancing the accuracy and reliability of the method's assessment results.