Data analysis to support flooding risk identification: approach in Lisbon

09:00 Thursday 30 May

SS037 • OC217

Room S2

 

Maria Do Céu Almeida (Portugal) 1; Maria João Telhado (Portugal) 2; Marco Morais (Portugal) 2; Luisa Coelho (Portugal) 2; Ruth Lopes (Portugal) 3; João Barreiro (Portugal) 3

1 - LNEC; 2 - CML; 3 - HIDRA

Consolidated urban areas are complex and multisector systems involving multiple strategic urban services and stakeholders. Estimated effects of climate dynamics on these areas generally implies aggravation of existing conditions in terms of risk. Increasing urban resilience of consolidated urban areas is not a straightforward task and requires the adoption of integrated and comprehensive approaches incorporating the interdependencies between systems, while using parsimony to obtain realistic results.

A common hazard affecting many cities is flooding. This is a typical situation where failure of drainage infrastructures (mostly underground) and lack of adequate overland flow pathways can affect several city functions as well as causing damages and other consequences. The source of flooding can be intense rainfall, coastal overtopping, among others.

Data is often scarce to allow using validated complex quantitative tools such as physically based mathematical modelling. Therefore, available data needs to be analysed in order to extract as much information as possible.

Within the EU H2020 funded project RESCCUE developments, hazard assessment has been carried out for main climate variables affecting the RESCCUE cities, one of which is Lisbon. In this case, flooding represents an important and recurrent hazard affecting the city and thus development of flooding hazard maps for current situation and selected scenarios is of interest.

Available detailed models for hydrologic and hydraulic behaviour have been developed for planning purposes but are limited by data available on existing infrastructure and on operational condition of networks components. Data for model calibration and validation is also limited and therefore available data from historical flooding events is of large value to ensure the reliability of the resulting hazard maps for the city.

In this paper, the methodology adopted to derive the hazard maps is presented as well as the results obtained for the current situation, to be used as the baseline scenario to compared with selected climate change scenarios and adaptation measures potential effect. Additionally, an illustration of application of the flooding hazard maps to estimate transport infrastructures exposure is also presented.