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For reliable prediction of urban pluvial flooding it is essential to have reliable spatial and temporal rainfall prediction at an appropriate scale. Radar data are considered to be the most reliable. However, many urban catchments do not have access to radar data. This paper presents a new methodology for rainfall forecasting based on a network of raingauges. The methodology predicts rainfall at each raingauge location based on the Support Vector Machine (SVM) technique improved with Singular Spectrum Analysis (SSA). The prediction of the spatial distribution of rainfall is based on interpolation techniques. The forecasted rainfall fields are then used as inputs for simulation of drainage systems to obtain a short-term flood prediction. The proposed methodology is tested using real data from a case study in Coimbra, Portugal and the results obtained showed that it is possible to predict the water level 30 minutes in advance when using this methodology. 9 8p Em CD DHA/NES 2011 11 a 16 de Setembro

A more reliable flood forecasting could benefit from higher-resolution rainfall forecasts as inputs. However, the prediction lead time of the operational rainfall forecasting models will substantially diminish while sub-hourly (e.g., 5-min) rainfall forecasting is required. A method that integrates the SVM (Support Vector Machine) and Cascade-based downscaling techniques is therefore developed in this work to carry out high-resolution (5-min) precipitation forecasting with longer lead time (45-60 minutes). The 5-min raingauge observations from Coimbra (Portugal) are employed to assess the proposed methodology. A comparison with the conventional SVM is also conducted to study the possible benefit of using the proposed methodology to carry out shortterm rainfall forecasting. 6 8p Em CD DHA/NES 2011 11 a 16 de Setembro

Within the scope of the Alcântara WWTP rehabilitation project, advanced physical-chemical treatment was introduced to up-grading existing primary treatment of wet-weather flows. In addition, biofiltration and ultra-violet disinfection of dry-weather flows were installed. A conceptual model using historical rainfall series was applied to the Alcântara catchment to evaluate the CSO discharges for a combination of scenarios of storage and treatment. Despite its simplicity, the model closely matches measured hydrographs. Results show important reductions of the volume, frequency and duration of CSO discharges associated with increasing the WWTP capacity, although the benefits become less significant as the WWTP capacity raises. Results also highlight that, for small WWTP capacities, a slight increase in the WWTP capacity leads to the same reduction of the discharged volume as an appreciable increase in storage capacity. However, for high treatment capacities, benefits from storage increase significantly compared with those resulting from a rise in the WWTP capacity. Benefits from storage also become less significant as storage capacity increases. Higher benefits are achieved for the bathing season, then improving conditions for recreation uses in Tagus estuary. Results may provide an important technical contribution to the decisionmaking process. 2 1 8p Em CD DHA/NES 2011 11 a 16 de Setembro

Short-term surface flood modelling requires reliable estimation of the distribution of floods over urban catchments with sufficient lead time in order to provide timely warnings. In this paper new improvements to the traditional Support Vector Machine (SVM) prediction technique for rainfall prediction are presented. The results obtained using the new improvements, such as enhancement of SVM prediction using Singular Spectrum Analysis (SSA) for pre-processing the data and combined SSA and SVM with a statistical analysis that give stochastic results to AI-based prediction, are compared with the results obtained using the SVM technique only. When applying the SVM technique to the rainfall data used in this study, the results showed an underestimation of the rainfall peaks. When using SSA for preprocessing the rainfall data the results are significantly better. The new stochastic approach proved to be useful for estimating the level of confidence of the forecast. 16 8p Em CD DHA/NES 2011 11 a 16 de Setembro

This paper presents a methodology for the integrated planning of urban development, overland flow and flood mitigation and control. The sewer network is sized for a 5-year return period, but the appropriate landscape reshaping and detention basins integrated in a green corridor ensure safe and controlled flows for storms with a 100-year return period. Design criteria and a detailed description of the modelling activities are presented and applied to a real case. The solution obtained is also able to deal with exceptional conditions, such as increased rainfall due to climate change or blocking the bottom outlet of a detention basin, and is versatile in allowing for future adaptations with reduced interventions and costs. Urban planning and landscape reshaping allowed for low heights of overland flow, which assigns some confidence to the 1D overland flow modelling. A conventional sewer system (without any detention basin) designed for return periods of 5, 10 and 20 years would cost only less 13%, 9% and 4%, respectively, than the proposed system. However, maximum flow rates discharged to downstream would increase about 60%, 85% and 110%, respectively, compared with the obtained solution. Results highlight the potential benefits of a wider use of such solutions. 3 1 8p EM CD DHA/NES 2011 11 a 16 de Setembro