Author(s): Katharina Baumgartner, Bernhard Gems, Stefan Walder, Markus Federspiel, Markus Aufleger
Linked Author(s): Katharina Baumgartner
Keywords: Bed-load transport, flood protection, morphodynamic-numerical-modelling
Abstract: During the last decades, flood risk management has become increasingly important in the Alpine region. Bed-load transport is an important driving factor for riverbed formation. The Inn River located in the Lower Inn valley is a focus of intensive research and the aim is to decrease the flood risk. Morphological changes during flood events significantly influence the channel capacities. The bed-load transport within the river system, or rather the erosion and deposition processes, can have significant impact on the effectiveness of flood protection measures and the dimensioning of retention areas. The work presented in this paper is aimed at the analysis of the influence of the movement of sediments and the associated morphological processes on a large system of flood protection and uncontrolled and controlled retention areas in the gravel-bed river Inn. In order to analyze the impacts of morphodynamic changes on the effectiveness of the planned measures and to identify sensitive areas for retention control, a multi-fractioned bed-load transport simulation is applied. The study focuses on the 75 km long reach of the Inn River between the city of Innsbruck and Kufstein in Tyrol (Austria). The 100-yr design flood hydrograph is analyzed with the numerical model. Grain size distributions are obtained from a field survey along the entire stretch of the Inn River and the relevant tributaries. This study points out that morphodynamic analysis affords an insightful basis for planning of flood protection and retention areas, in particular for retention control of the intake structures. To reach an efficient and optimized peak reduction in the main river and to control fluxes into retention areas, it is crucial to analyze the morphodynamic processes
Year: 2017