1 integrated modelling 1 d / 2 d and performance assessment to support floods management . application to stormwater urban drainage systems in estuarine areas

Urban flooding occurrence has associated significant impacts and negative effects that require an adequate assessment, taking in consideration the different consequences that can be associated with them. This thesis proposes a methodology based on the development and use of a 1D/2D integrated mathematical modelling and, subsequently, the application of the technical performance assessment to support the flood management in estuarine areas. The 1D/2D integrated mathematical 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 (PI) using the information provided by 1D and 1D/2D integrated modelling. The set of PI was based on those from the International Water Association (Matos et al., 2003) for wastewater services, applicable to flooding management of stormwater systems, and some new PI proposed based on the modelling (1D and 1D/2D) capabilities. It is also assessed the advantages and disadvantages of the use of information obtained by 1D/2D modelling in comparison to 1D modelling. The methodology was tested and validated for the case of study of Dafundo where the risk of flooding occurrence is focused on the downtown area. It was possible to identify a significant impact of the operational conditions in the flooding occurrence related to stormwater drainage system, being aggravated for high tide levels on the Tagus estuary.