Flooding in coastal areas (rivers, estuaries and the sea) is the most widely distributed of all natural hazards across Europe, threatening many millions of people. In recent years Europe has suffered over 100 major damaging floods. Since 1998 they have caused over 700 fatalities, the displacement of an estimated half a million people and at least 25 billion euro in insured economic losses (European Environment Agency). On 2007 the European Union recognized the importance of this hazard and a new European Directive (2007/60/EC, ec.europa.eu/environment/water/flood_risk/) on the assessment and management of flood risk was introduced and sets out how member states must plan for the management of flood risk.

The Ria de Aveiro Littoral is considered a flood-prone urban region. Ria de Aveiro is a shallow coastal lagoon connected to the Atlantic Ocean through a single inlet and is located in the central coastal zone of Portugal, between Douro River mouth and Cape Mondego, integrating the Vouga river catchment area (Figure 1). The Ria de Aveiro and its main tributary (Vouga river) present huge floods that inundate the low-lying adjacent lands. The surrounding littoral stretches of Vagueira-Mira and Esmoriz-Furadouro (Figure 2) show coastal erosion problems with high risk of sand spit rupture (EEA 2006; reports.eea.europa.eu/eea_report_2006_6/en ).

Much of the flooding events occur during adverse weather conditions. Heavy rainfall causes high river flows. Low pressure N/NW of Portugal and high pressure S/SW and strong southerly winds cause surges in the Portuguese coast. High tides also impact on the level of flooding, as well as the mean sea level evolution. The morphodynamic of the inlet channel also depends on the mean sea level and on the north east Atlantic wave climate regime. Furthermore, these last factors and the sediment supply also impact the coastal erosion of Ria de Aveiro Littoral (IHRH, 2003; www.eurosion.org/reports-online/reports.html).

Climate changes can amplify the effects of all these forcing. An extensive quantity of research exists about this topic both internationally and in Portugal. Recent publications include the Intergovernmental Panel on Climate Change 4^th Assessment Report (IPCC, 2007) and the SIAM II Project Final Report (Santos & Miranda, 2007). Ambiguity remains with respect to future climate conditions, and a range of six different scenarios is considered by the IPCC. All indicate more extreme weather conditions, with an increase in rainfall depth and intensity, a rise in sea levels, an increase in the intensity of extratropical cyclones in the North Atlantic and therefore of the coastal storms and surges, and changes in the wave climate. Due to their morphological and geological features, floodplains underwent severe urbanization, which lead to an increase of risk of flooding. In upcoming decades the climate changes will strongly change hydrodynamics and morphodynamics in coastal and river environments.

These scenarios clearly show that comprehensive and efficient approaches for the analysis, evaluation and management of flooding risk are necessary in order to back the emergencies plans and the urban planning and management systems. These tools are crucial in the support of the Decision Support System.

The main goal of this proposal is to perform flood risk assessment and define adaptation strategies for the Ria de Aveiro and the Vagueira-Mira and Esmoriz-Furadouro stretches. Coastal morphodynamic models in conjunction with global climate change models and sea-level rise scenarios will be developed and used to determine the present and future coastal flooded areas.

Analysis of storminess over the North Atlantic and storm surge and simulated daily meteorological data (near-surface wind, rainfall) for the Aveiro coastal zone, for the 1971-2000 and for the 2071-2100 periods will be prepared and analyzed, with special emphasis on the IPCC A2 SRES scenario. The wind data will be used to force the wave generation and propagation models WaveWatch3 and SWAN, which will produce wave climatology for the Aveiro littoral. Freshwater discharge scenarios will be determined for the Vouga river from the rainfall. All these specific results and the IPCC predictions for the mean sea level evolution will be used to force the ELCIRC/MORSYS2D hydro/morphodynamic models for the Ria de Aveiro and the numerical coastline evolution model LTC for the Aveiro Littoral, in order to determine flood hazard maps of the Ria de Aveiro Littoral for the different scenarios. Adaptation strategies and measures will be proposed for flooding prevention and mitigation, considering the different scenarios developed, lessons learned and policies recommendations for climate changes adaptation.

The project will adopt a multidisciplinary perspective by integrating methodologies of climatology, hydrology, coastal and estuarine hydrodynamics, numerical modelling, urban and regional planning, taking advantage of the integrated approach and multiple expertise of the research team to achieve the proposed goals.

IHRH, 2003. EUrosion - A European Initiative for Sustainable Coastal Erosion Management. Guidelines for Developing Local Information Systems (Study cases of River Douro - Cape Mondego stretch). Editors F. Veloso Gomes; F. Taveira Pinto; L. das Neves & J. P. Barbosa, Porto. 182 p.

IPCC, 2007. Climate Change 2007: The Physical Science Basis. Contribution of the Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z.Chen, M.Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, Uninted Kingdom and New York, Ny, USA, 996 pp.

Santos, F.D. & P. Miranda, 2007. Alterações Climáticas em Portugal. Cenários, Impactos e Medidas de Adaptação, Projecto SIAM II, Gradiva, Lisboa, 506 pp

CESAM members on this project

Alfredo Moreira Caseiro Rocha
Researcher

PhD Research Fellow

Carina de Lurdes Bastos Lopes
PhD Research fellow

Carlos A. F. Marques
Researcher

João Miguel Dias
Coordinator

Maria de Fátima Lopes Alves
Researcher

Paulo A. Silva
Researcher

Peter Cornelis Roebeling
Researcher