Author(s): Laszlo Koncsos; Zsolt Kozma
Linked Author(s):
Keywords: Sediment accumulation; Floodplain; Hydrodynamic simulation
Abstract: Hungary is affected most of all by the hazard of inundation in Europe. Recent extreme flood events and the evidence of unfavourable changes in inundation characteristics made it clear that a new concept of flood-defense must be set up. In order to create an adequate long term strategy, the different processes causing the alteration of flood event features must be explored and taken into account. Considering this demand the aim of this research was to analyze flood induced sediment accumulation over floodplains as a possible affecting factor. Our primary goal was to estimate the distribution of the annual increment in the sediment layer’s thickness along the Hungarian section of River Tisza. The research included the application of an existent model package as well as model development. The estimation was performed with the help of a simplified accumulation model that consists of a suspended matter sedimentation module and a one-dimensional hydrodynamic model. We performed model calculations along the whole Hungarian section of the Tisza with generated – but statistically realistic – input data. Our results indicate that on the long run the suspended matter deposition in the floodplain may lead to major morphologic changes. In case of River Tisza the average rate of sediment accumulation was estimated to be 0. 77 cm/year. Middle Tisza region turned out to be the mostly affected section with an average of 1. 34 cm/year. The resulting values meet data from the literature. As further advantage, our results serve as the base information for forecasting the changes in water carrying capacity of the floodplain and the likelihood of undesired flood events caused by sediment accumulation.
Year: 2007