<p>The modeling of waves caused by landslides is an active area of intensive research, with studies including landslides on flat-bottom or sloping beaches, using analytical, numerical, or experimental approaches. This article focuses on the study of landslide waves generated in long and narrow bays, on which the Saint-Venant equations hold. In this article, our previously developed numerical scheme is revisited and modified to accommodate landslide movements. The ability of the scheme to simulate the wave generated by landslide in U-shaped bays is validated using analytical solutions. Further, we investigate the shoaling processes experienced by waves in the U-shaped bay, as well as resonance phenomena, obtaining results that align perfectly with analytical predictions. We also analyze the nonlinear effects revealed by numerical simulations. Finally, we apply our model to a more realistic scenario, providing estimates of wave run-up in Palu Bay.</p>