Dam-break represents a potential flood hazard for population at downstream due to the sudden release of the water stored in the reservoir. The prediction of dam-break wave parameters is complicated furthermore by the presence of irregularities in the channel. This paper aims to present an experiment and numerical simulations of dam-break flood wave in an initially dry flume with a hump. A triangular-shaped bottom obstacle was placed downstream the dam site in the channel to provide the effects of both bottom slope and abrupt change in topography on propagation of dam-break flood waves. A new experiment was carried out in a smooth rectangular cross-section channel by using digital image processing. Flow behaviour was synchronously recorded with three adjacent CCD cameras through the glass walls of the entire downstream channel. This adopted measuring technique eliminates the necessity for test repetition due to capturing the whole flow field at once. Not only continuous free surface profiles at various times but also time evolutions of the water levels for selected locations were simply acquired from the video records of the image processing by virtual wave probe. Furthermore, dam-break flow was numerically simulated by the VOF-based CFD commercial software package FLOW-3D, which utilizes two distinct approaches, namely the Reynolds-averaged Navier-Stokes equations (RANS) with a k-epsilon turbulence model and the simple Shallow Water Equations (SWEs). Comparison between the computed results and the experimental data shows that both numerical models reproduce the flow behaviour with reasonable accuracy and the agreement is slightly better in RANS model compared to simple SWE model. Current experimental data can be useful for validation of other numerical models. (C) 2014 International Association for Hydro-environment Engineering and Research, Asia Pacific Division. Published by Elsevier B.V. All rights reserved.