Author(s): Fang Yenn Teo; Yuk San Liew; Roger A. Falconer; Bin Liang Lin
Keywords: Flooding; Flood hazard risk to vehicles; Hydrodynamic modelling
Abstract: Many countries globally have experienced considerable changes in their climatic and meteorological conditions, leading to extreme inundation extent and increased frequency in flooding. The problems arising range from minor impacts, such as frequent flash flooding, to major incidents, where larger areas are inundated for several days after a storm event. The spilling and flowing of floodwater over these areas can become a serious problem, where it can even cause potential risk to human life, as well as health and much damage to property. Recently, flood hazard relating to vehicles have become more noticeable. Thus, it is desirable to assess the hydraulic behaviour and safety degree of vehicles during floods using hydrodynamic models. In this paper, the numerical model for assessing the flood hazard risk relating to vehicles has been applied to establish an understanding of the hydrodynamics of floodwater flows over floodplains with vehicles; a condition which can be very important for extreme storm events, or even moderate storm events, when the storm water system is insufficient to drain away the surface runoff. The calibrated and verified numerical model has been included to simulate the conditions with different Average Recurrence Intervals (ARI) in a real floodplain, at the township of Muar, Johor, Malaysia. Extensive investigations have been undertaken to investigate the effects of vehicles on floodwater flow propagation over floodplains and, on the other hand, the influence of the floodwater flows on the stability of model vehicles. The two principal factors of hazards (i. e. the floodwater depth and flow velocity) that affect the stability of model vehicles have been identified to estimate the flood hazard risk relating to vehicles, with the aim of studying the impacts on aspects of the hydrodynamic processes. Comparisons of the velocity profiles and water elevations have been undertaken. The results have highlighted that the model vehicles had a significant impact on the floodwater flow propagation and the hydrodynamic processes in the flooded area. The numerical model can be readily used to estimate the degree of hydraulic stability for vehicles, and it is also invaluable for assessing the potential flood hazard risk to vehicles for improved flood risk management.