Floodplain modelling for real-time use based on an interlinked numerical 1D/2D model

During real-time flood management detailed knowledge of the hydraulic situation is essential, e.g. for early identification of possible failure locations or vulnerable supply roads. Climate-based changes in flood statistics make this even more important. Anticipatory hazard analysis often cannot be employed because of the multiplicity of possible events. Therefore, numerical models are required to enable the user to recognize current regional as well as local hazards and evaluate possible options for action. This article describes several possibilities for flood simulations in hydraulically complex flow areas with emphasis on real-time use (minimal computational effort, user-based changes in hydrologic and topographic boundary conditions, stable calculations). For this study a section of the Elbe River was examined using different types of models. The quality of the implemented interlinked 1D-2D-model (1D river channel, 2D floodplain simulations) was analysed by comparison of calculated results, in which a noticeable decrease in computational time without a significant loss of accuracy was attained.