Tsunamis have been observed to reach coastal areas in the form of long bores and it is their long lengths that sets them apart from other coastal waves. Consequently, the present work focuses on the analysis of the bore lengths and their influence on the flooding processes. Bores are generated in the laboratory employing a dam-break system with different reservoir lengths and a programable long-stroke wavemaker. The experimental data show the dependency of inundation depth, runup height and flooding duration on the bore length and the bore strength at the beach toe and the slope. Flow velocities under solitary waves, undulating bores and breaking bores are measured in the constant water depth and slope regions employing a High-Speed PIV system (HSPIV) to improve the current knowledge of swash flows produced by bores.