Sediment Transport and Erosion in Viskan River, South Sweden

Abstract: This master thesis study presents the results of sediment transport analysis along Viskan, located in south Sweden. The main processes cover building a hydrodynamic model, studying parameters that define sediment transport, modelling sediment transport within the river, mapping out erosive stretches and comparing to observed eroded locations, and finally comparison of different transport functions how they influence the results. The study section has a total distance of 33.78 km. In HEC-RAS, the one-dimensional model was employed. To build the model on the already provided Digital Elevation Model, the HEC-RAS Mapper was used. Steady flow and sediment transport simulations were then done to obtain the hydrodynamics and sediment transport of the river respectively. After sediment transport simulations, 5 most eroded cross sections: cross section (XS) 2374, XS 38919, XS 45988, XS 49945 and XS 88725 are used for possible causes analysis. Then the observed erosion compared with simulation results was taken and all the cross sections are shown reasonable results from HEC-RAS. Furthermore, the comparison of the Meyer-Peter and Müller transport function, the Laursen (Copeland) transport function, the Engelund-Hansen transport functions and the Wilcock-Crowe transport function were analyzed. Results show the Engelund-Hansen transport functions are more sensitive for deposition and the Meyer-Peter and Müller transport function is the most balanced function with the gentlest changes.