1D/2D integrated modelling and performance assessment to support flood management

Abstract

Urban flooding occurrence has significant impacts and negative effects that require an adequate assessment, taking into consideration the different consequences associated with them. This study proposes a methodology based on the development and use of a 1D/2D integrated mathematical modelling and subsequent application of the technical performance assessment to support the flood management in estuarine margins. The 1D/2D integrated modelling is developed using the combination of Mike Urban and Mike Flood software through the application of the Overland Flow tool. The performance assessment in stormwater systems is based on the application of performance indicators (PIs) using the information provided by 1D and 1D/2D integrated modelling. The set of PIs includes a part from the system of the IWA for wastewater services, those that are applicable to flooding management of stormwater systems; another part corresponds to some new PIs proposed, based on the modelling capabilities (1D and 1D/2D). The advantages and disadvantages of the use of information obtained from 1D/2D modelling in comparison to 1D modelling is also analysed. The methodology was tested and validated for the Dafundo case study, where the risk of flooding occurrence is focused on the downtown catchment area.