<p>Landslide dam overtopping can lead to catastrophic flooding, making it critical to understand the factors affecting dam breaching processes. This study quantitatively analyzes the influence of lake geometry and upstream inflow on landslide dam breaching through a series of validated numerical experiments. Initially, we confirmed the geometric and Froude similarities of the numerical models, followed by an analysis of breach progression, hydrodynamic variations, and erosion under different lake configurations and inflow conditions. Results highlight that lake area and inflow rate significantly impact key breach parameters, including headward erosion duration, peak discharge time, and maximum discharge rate. Quantitative relationships were established, showing that increased lake area prolongs headward erosion, while higher inflows accelerate erosion and increase peak discharge. The proposed empirical model incorporates these factors to enhance flood risk prediction and emergency response. This study advances the understanding of landslide dam failures, providing crucial insights for improved hazard assessment and management.</p>