Assessment of Seismic Disaster Risk in the Dingri Earthquake Based on Fault-Induced Ground Motion Effects

Accurate and efficient seismic disaster risk assessment is essential for disaster prevention and emergency response, particularly in active tectonic zones characterized by complex geological and geomorphological conditions. However, existing approaches often fail to comprehensively integrate multiple influencing factors or to adequately capture regional heterogeneity. This study proposes a novel three-dimensional integrated framework for seismic risk assessment that combines subsurface structure, surface environment, and building characteristics, based on multi-source remote sensing data and detailed field investigations. The results demonstrate that fault dynamics play a dominant role in controlling seismic risk differentiation, with hanging-wall areas exhibiting a 42.6% higher comprehensive risk than footwall regions (p < 0.05). Mortality risk increases sharply within 200 m of active faults (odds ratio = 3.17, p < 0.01), reflecting the combined effects of fault properties, topography, and site conditions. Moreover, strong coupling between geomorphological factors and structural vulnerability significantly amplifies disaster impacts, as evidenced by the prevalence of vulnerable civil structures (91.31%) within MMI IX zones and the resulting pronounced spatial variability in mortality. An optimized village-level risk assessment model further achieves high predictive accuracy (R² = 0.7494), with spatial patterns closely matching observed mortality distributions. These findings highlight the critical roles of fault-related effects (hanging wall and footwall asymmetry) and ground-motion amplification mechanisms in shaping earthquake casualty patterns, providing a robust scientific basis for targeted disaster mitigation and prevention strategies in active fault zones. Future work will further incorporate InSAR-derived deformation monitoring and geotechnical investigations to refine the understanding of fault micro-mechanics and to enhance dynamic seismic risk assessment models.