Adaptation to flood risk – results of international paired flood event studies: Adaptation to flood risk

Authors: H. Kreibich, G. Di Baldassarre, S. Vorogushyn, J.C.J.H. Aerts, H. Apel, G.T. Aronica, K. Arnbjerg-Nielsen, L.M. Bouwer, P. Bubeck, T. Caloiero, D.T. Chinh, M. Cortès, A.K. Gain, V. Giampá, C. Kuhlicke, Z.W. Kundzewicz, M.C. Llasat, J. Mård, P. Matczak, M. Mazzoleni, D. Molinari, N.V. Dung, O. Petrucci, K. Schröter, K. Slager, A.H. Thieken, P.J. Ward, B. Merz
As flood impacts are increasing in large parts of the world, understanding the primary drivers of changes in risk is essential for effective adaptation. To gain more knowledge on the basis of empirical case studies, we analyze eight paired floods, i.e. consecutive flood events that occurred in the same region, with the second flood causing significantly lower damage. These success stories of risk reduction were select ed across different socio-economic and hydro- climatic contexts. The potential of societies to adapt is uncovered by describing triggered societal changes, as well as formal measures and spontaneous processes that reduced flood risk. This novel approach has the potential to build the basis for an international data collection and analysis effort to better understand and attribute changes in risk due to hydrological extremes in the framework of the IAHSs Panta Rhei initiative. Across all case studies, we find that lower damage caused by the second event was mainly due to significant reductions in vulnerability, e.g. via raised risk awareness, preparedness and improvements of organizational emergency management. Thus, vulnerability reduction plays an essential role for successful adaptation. Our work shows that there is a high potential to adapt, but there remains the challenge to stimulate measures that reduce vulnerability and risk in periods in which extreme events do not occur.

Towards a better understanding of the evolution of the flood risk in Mediterranean urban areas: the case of Barcelona

Authors: Maria Cortès, Maria Carmen Llasat, Joan Gilabert, Montserrat Llasat-Botija, Marco Turco, Raül Marcos, Juan Pedro Martín Vide, Lluís Falcón.


This contribution explores the evolution of the flood risk in the MetropolitanArea of Barcelona (MAB; Northeast Spain) from 1981 to 2015, and how it has beenaffected by changes in land use, population and precipitation. To complete this study, weanalysed PRESSGAMA and INUNGAMA databases to look for all the information relatedto the floods and flash floods that have affected the chosen region. The ‘‘Consorcio deCompensacio´n de Seguros’’, a state insurance company for extraordinary risks, provideddata on economic damage. The extreme precipitation trend was analysed by the FabraObservatory and El Prat-Airport Observatory, and daily precipitation data were providedby the State Meteorological Agency of Spain (AEMET) and the Meteorological Service ofCatalonia (SMC). Population data were obtained from the Statistical Institute of Catalonia(IDESCAT). Changes in land use were estimated from the land use maps for Cataloniacorresponding to 1956, 1993, 2000, 2005 and 2009. Prevention measures like rainwatertanks and improvements to the drainage system were also been considered. The specificcase of Barcelona is presented, a city recognised by United Nations International Strategyfor Disaster Reduction as a model city for urban resilience to floods. The evolution of floodevents in the MAB does not show any significant trend for this period. We argue that theevolution in floods can be explained, at least in part, by the lack of trend in extremeprecipitation indices, and also by the improvements in flood prevention measures.

Download: Cortès et al._2017_Towards a better understanding of the evolution of the flood risk in Mediterranean urban areas the case of Barcelona