Author(s): Wei Hu; George Jacoub; Roberto Kohane; Bernhard Westrich
Linked Author(s): Bernhard Westrich
Keywords: Numerical modelling; Uncertainties; Flood protection; Sediment transport
Abstract: Prediction of future flood risk on river morphology and safety of levees is considered to be a major challenge for hydraulic engineers. Flood risk analysis can be characterised by taking some factors into account that lead to appropriate decisions of risk assessment. These factors are related to field measurements of flow and transport, lack of data (uncertainties) and human interference in river channels and on floodplains. Numerical simulations are often used to estimate the flood risk that the physical processes are very complex occurring during flood flows. This paper presents a numerical study of a reach of the River Inn, in Germany, where uncertainties of inflow suspended sediment conditions exist. The area of investigation extends over 7 km along the River Inn, with a hydropower station at the downstream end of a reservoir. The aim of the study is to investigate the maximum water level as related to sediment erosion processes for a given design discharge hydrograph (HQ100) and also to estimate the spatial distribution of eroded sediments. To do this aim, two one-dimensional numerical programs, i. e. HEC-RAS for hydrodynamic and WSPSED for suspended sediment transport, are used. Using these models, calibration of water level, estimated inflow suspended sediment and sedimentation and erosion parameters for three flood events occurred in 1999, 2002 and 2004 are performed. Based on the calibrated parameters of flow and transport, a predicted spatial distribution of eroded and deposited sediments and the total mass/volume of sediments could be calculated during flood design discharge.
Year: 2005