Graduation of Gijs Nannenberg
River bed response to a changing hydrograph due to climate change
Professor of graduation: Dr. Ir. A. Blom
Supervisors: C. Ylla Arbós (TU Delft), Dr. Ir. R. Schielen (Rijkswaterstaat, TU Delft), Dr. T. Bogaard (TU Delft)
The objective of this thesis is to assess the effects of climate change on the initial, transient and equilibrium response of mixed-sediment river. Climate change will cause changes to hydrographs, which in turn affects sediment transport capacity and thereby the river bed profile. In order to create a better understanding of the processes in play we analyse a theoretical situation using the Lower Rhine as reference. The river Rhine is a heavily engineered river. The exact effects of climate change are therefore difficult to predict, as human intervention is significant. A simplified version of the Rhine can however give an insight into river response to climate change.
First an analyses of historical discharge and future discharge of the Lower Rhine was made, which gave an insight in the changes to the hydrograph that can be expected in the future. Next a model was made representing a theoretical river reach. For this river reach the upstream hydrodynamic boundary is varied and the results of these variations are analysed. Using the results of this model and the hydrograph expectations it was discussed what can be expected to happen to a river bed under these circumstances.