Drainage system obstructions in real time simulation and its impacts on urban floods modelling

Abstract

The urbanization process significantly alters the hydrological flow patterns of natural watersheds, resulting not only in an increase in liquid flows but also in the amount of eroded sediments transported by surface runoff. In the context of urban flood modeling, the effects of sediment incorporation into the drainage system are generally limited to an increase in the roughness coefficient or the application of a reduction factor in the system's hydraulic capacity. This modeling approach decreases the reliability of extrapolating the results obtained for different situations used in model calibration, as it does not simulate the system clogging process itself but rather the effects it causes. Thus, the objective of this paper is to present the incorporation of a sediment transport and deposition module into MODCEL, a quasi 2D hydrodynamic model, to simulate the transport and deposition of sediments inside urban drainage pipes in real-time simulation, based on the moving bed approach. It was observed that the incorporation of the moving bed did not introduce significant complexities into the calculations nor compromise the model's performance, yielding more reliable results, especially for predicting simulation scenarios.