geosciences Article Framework for Offline Flood Inundation Forecasts for Two-Dimensional Hydrodynamic Models Punit Kumar Bhola *, Jorge Leandro and Markus Disse Chair of Hydrology and River Basin Management, Department of Civil, Geo and Environmental Engineering, Technical University of Munich, Arcisstrasse 21, 80333 Munich, Germany;
[email protected] (J.L.);
[email protected] (M.D.) * Correspondence:
[email protected]; Tel.: +49-89-289-23919 Received: 19 July 2018; Accepted: 11 September 2018; Published: 13 September 2018 Abstract: The paper presents a new methodology for hydrodynamic-based flood forecast that focuses on scenario generation and database queries to select appropriate flood inundation maps in real-time. In operational flood forecasting, only discharges are forecasted at specific gauges using hydrological models. Hydrodynamic models, which are required to produce inundation maps, are computationally expensive, hence not feasible for real-time inundation forecasting. In this study, we have used a substantial number of pre-calculated inundation maps that are stored in a database and a methodology to extract the most likely maps in real-time. The method uses real-time discharge forecast at upstream gauge as an input and compares it with the pre-recorded scenarios. The results show satisfactory agreements between offline inundation maps that are retrieved from a pre-recorded database and online maps, which are hindcasted using historical events. Furthermore, this allows an efficient early warning system, thanks to the fast run-time of the proposed offline selection of inundation maps. The framework is validated in the city of Kulmbach in Germany. Keywords: database; flood forecast; flood inundation map; hydrodynamic models 1.