Test the web based interface of a multi-scale ...

The purpose was to explore the possibility of coupling a large-scale high-resolution hydrological model (HYPE) to a local hydrodynamic model (MIKE URBAN) into a multi-scale urban flood forecasting system. A 1D-2D local flood model was set up for the Kærby catchment in Aalborg, Denmark. The model expands the local catchment setup by simulating the flood extent and water depth on the terrain in 2D. This experiment investigates the potential gain in flood forecasting performance by utilizing the fast-computational time of HYPE to forecast river discharge as a boundary condition for the 1D-2D local model setup in Aalborg. Known flood prone areas in the catchment along the river system are not observed in flood simulations using the current available urban drainage models. This is mainly due to the description of the river discharge from a flow and water level relation (Q-h relation) being incorrect during high-discharge scenarios. Therefore, substituting the river discharge boundary condition from a Q-h relationship to a simulated river discharge from a calibrated HYPE model might improve performance. Two numerical weather forecasts and a radar nowcast (representing e.g. different scale/resolution or different observational sensors or different forecasting methodology) was used as forcing data for the coupled HYPE and 1D-2D urban drainage flood model. This coupled model with the combined forecasts expands the current limitations in flood forecasting in the Aalborg catchment, where previous attempts were unable to map the flood prone areas around the river system correctly. For more information and possibility to test different settings concerning rain events and forecasts, see the web based interface by following the link.