<p>Strong ground motion can trigger thousands of landslides across disaster-affected regions, leading to substantial casualties and property damage. Regional-scale landslide modeling typically relies on the Newmark method and peak ground acceleration or peak ground velocity derived from simplified earthquake time histories, as well as a digital elevation model (DEM). This approach neglects the contribution of the spatial resolution of the DEM to representations of regional seismic fields and coseismic landslides. To explore the relationship among DEM spatial resolution, regional seismic fields, and coseismic landslides, six different DEM resolutions were used in simulating ground motion to assess the landslide risk for the 2013 Lushan earthquake. The analysis integrated the spectral element method (SEM) with the Newmark sliding block model across various DEM resolutions. The findings reveal that increasing the DEM resolution significantly improves the representation of topographic and geological features, which in turn has a substantial effect on the accuracy of seismic simulations and landslide assessments. Moreover, the results demonstrate that this methodology is effective for the rapid, regional-scale prediction of coseismic landslides, providing valuable insights for disaster response and risk mitigation efforts.</p>