Real-time Prediction of Urban Inundation based on SWMM 1D-1D Model

Abstract

The concept of a Major/Minor system was applied to use urban flood prediction techniques, based on rainfall forecasts and real-time simulations, to reduce flood damage, by notifying a possible flood risk in advance. The SWMM one dimensional (1D)-two dimensional (2D) model has become the standard approach used in urban flood modeling, as it can realistically express the interaction between drainage networks and road surfaces. However, it is limited to the flood analysis of small areas due to its two-dimensional model characteristics, such as its long simulation time. Therefore, the SWMM 1D-1D model, which is fast enough to be applied to real-time simulations, is applied to real-time flood forecasting. To improve the accuracy of the model, SWMM 1D-1D model was calibrated using the SWMM 1D-2D model simulation results, and the SWMM 1D-1D model simulation results were extracted using the SWMM5 DLL and EXCEL VBA to analyze the flood situation. Finally, the applicability of the SWMM 1D-1D model was reviewed based on a rainfall event that occurred on 25 August 2014, assuming an hour of predicted rainfall.