GAMA (Grupo de Análisis de situaciones Meteorológicas Adversas) es un grupo de investigación interdisciplinario del Departament d’Astronomia i meteorología de la Universitat de Barcelona. Sus principales lineas de investigación son: el estudio de fenómenos meteorológicos adversos y riesgos naturales (episodios de precipitaciones extremas, inundaciones, riadas, tormentas, sequías, incendios forestales,…); Cambio climático (análisis de series meteorológicas, tendencias y anomalías, impacto del cambio climático en los riesgos naturales); Previsión hidrometeorológica (nowcasting, estacional); Análisis del impacto social, percepción y comunicación social de los riesgos naturales.

Con el fin de poder difundir información relacionada con las líneas de estudio, nos hemos propuesto empezar un blog con el título de Riesgos Naturales, un espacio de divulgación meteorológica, así como de comunicación y sensibilización frente a los riesgos naturales y el cambio climático.


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

Natural hazards and protective structures

What is it? A 2-week intensive course on Natural Hazards and Protective Structures

Who can take part? Students or lecturers who would like to learn about the French expertise on risks protection in mountain areas.

Where? Le Bourget-du-Lac campus. Several field excursions around Chambéry and in the Alps will be organised.

When? The programme will start on June 12th and end on the 23rd.

Leer más de esta entrada

3 nous artícles

On the key role of droughts in the dynamics of summer fires in Mediterranean Europe


Marco Turco, Jost von Hardenberg, Amir AghaKouchak, Maria Carmen Llasat, Antonello Provenzale, Ricardo M. Trigo


Summer fires frequently rage across Mediterranean Europe, often intensified by high temperatures and droughts. According to the state-of-the-art regional fire risk projections, in forthcoming decades climate effects are expected to become stronger and possibly overcome fire prevention efforts. However, significant uncertainties exist and the direct effect of climate change in regulating fuel moisture (e.g. warmer conditions increasing fuel dryness) could be counterbalanced by the indirect effects on fuel structure (e.g. warmer conditions limiting fuel amount), affecting the transition between climate-driven and fuel-limited fire regimes as temperatures increase. Here we analyse and model the impact of coincident drought and antecedent wet conditions (proxy for the climatic factor influencing total fuel and fine fuel structure) on the summer Burned Area (BA) across all eco-regions in Mediterranean Europe. This approach allows BA to be linked to the key drivers of fire in the region. We show a statistically significant relationship between fire and same-summer droughts in most regions, while antecedent climate conditions play a relatively minor role, except in few specific eco-regions. The presented models for individual eco-regions provide insights on the impacts of climate variability on BA, and appear to be promising for developing a seasonal forecast system supporting fire management strategies.

Article: http://www.nature.com/articles/s41598-017-00116-9

Analysis of geographic and orographic influence in Spanish monthly precipitation

J. Álvarez-Rodríguez, M. C. Llasat, T. Estrela

Precipitation is a major concern in water resources studies. Being a main variable, the inefficiency of historical ground network, particularly at higher altitudes where precipitation and runoff augmentations are expected, constitutes a major drawback. This work analyses the competence of Spanish historical precipitation network and explores the physiographic influence of elevation and orientation at a national scale. The usefulness of slopes is also explored. Nearly 12 000 monthly precipitation series recorded from the 19th century until the hydrological year 2004/2005 over a high-resolution topographic map (200 m) of Spanish territory are used. Comparable statistics and precipitation lapse rates are managed once a completion of gaps is accomplished. Then, Spanish yearly rates range from 0.3 to 1.2 mm m−1, reaching 1.5 mm m−1 in Northern Iberian Peninsula, diminishing at highest altitudes.

Article: http://onlinelibrary.wiley.com/doi/10.1002/joc.5007/full

Bias correction and downscaling of future RCM precipitation projections using a MOS-Analog technique

M. Turco, M.C. Llasat, S. Herrera, J.M Gutiérrez

In this study we assess the suitability of a recently introduced analog-based Model Output Statistics (MOS) downscaling method (referred to as MOS-Analog) for climate change studies and compare the results with a quantile mapping bias correction method. To this aim, we focus on Spain and consider daily precipitation output from an ensemble of Regional Climate Models provided by the ENSEMBLES project. The reanalysis-driven Regional Climate Model (RCM) data provide the historical data (with day-to-day correspondence with observations induced by the forcing boundary conditions) to conduct the analog search of the control (20C3M) and future (A1B) global climate model (GCM)-driven RCM values. First, we show that the MOS-Analog method outperforms the raw RCM output in the control 20C3M scenario (period 1971–2000) for all considered regions and precipitation indices, although for the worst-performing models the method is less effective. Second, we show that the MOS-Analog method broadly preserves the original RCM climate change signal for different future periods (2011–2040, 2041–2070, 2071–2100), except for those indices related to extreme precipitation. This could be explained by the limitation of the analog method to extrapolate unobserved precipitation records. These results suggest that the MOS-Analog is a spatially consistent alternative to standard bias correction methods, although the limitation for extreme values should be taken with caution in cases where this aspect is relevant for the problem.

Article: http://onlinelibrary.wiley.com/doi/10.1002/2016JD025724/abstract

10th HyMeX Workshop, 4-7 July 2017, Barcelona, Spain

Barcelona, Spain

The 10th HyMeX workshop will take place from 4 to 7 July 2017, in Barcelona, Spain.
It will be organized by the Water Research Institute (IdRA) and the Faculty of Physics from the University of Barcelona.

  • 2d circular in pdf format
  • Short abstracts for oral or poster presentations are invited related to the Mediterranean water cycle.
    Themes of particular interest are: heavy precipitation, flash-flood and vulnerabilities, Mediterranean cyclones, ocean circulation and dense water formation, droughts and water resources. Contributions on recent advances in prediction and management of the water cycle, its link with renewable energy, its related hazards and their impacts, from nowcasting to climate scales, are also welcome.
    Short abstracts can be submitted online here (Submission deadline is extended to 17 March 2017)
  • Registration form
Scientific committee
    M.C. Llasat (Chair, U. Barcelona, Es), V. Ducrocq (Co-chair, CNRM, Fr), P. Alpert (TAU, Is), M. Borga (U. Padova, It), I. Braud (IRSTEA, Fr), S. Coquillat (LA, Fr), Ph. Drobinski (LMD-IPSL, Fr), C. Estournel (LA, Fr), E. Flaounas (NOA, Gr), N. Fourrie (CNRM, Fr), V. Homar (UIB, Es), S. Khodayar (KIT, De), V. Kotroni (NOA, Gr), P. Quintana (O. Ebre, Es), S. Somot (CNRM, Fr), A. Turiel (ICM, Es)
Organizing committee
    M.C. Llasat, J. Martin-Vide, J. Bech, N. Casals, P. Guitchev (IdRA, U. Barcelona), M. Llasat-Botija, A. del Moral, M. Cortes, J. Gilabert, (U. Barcelona), P. Quintana (O. Ebre), L. Labatut, O. Roussot (CNRM, Fr)


Inundacions 1-3 novembre 2015

Fa un any, entre els dies 1 i 3 de novembre va tenir lloc un fort temporal que va produir nombroses inundacions en el territori. A Catalunya, les comarques més afectades van ser: Segrià, La Segarra, Barcelonès, Tarragonès, Baix Llobregat, Ribera d’Ebre, Baix Ebre, Urgell, Vallès Occidental, Baix Camp, Alt Penedès, Conca de Barberà.

Les quantitats de precipitació acumulada van ser superiors als 100 mm en molt punts, destacant els 220,7 mm del Parc Nacional dels Ports o els 189,9 mm del municipi de Viladrau entre els 3 dies que va durar l’episodi. Alguns rius es van desbordar provocant greus inundacions sobretot de baixos i soterranis. A Agramunt, la matinada del 3/11, es van produir 4 víctimes mortals degut al desbordament del riu Sió.

El pase de diapositivas requiere JavaScript.

(Fotos de A. Cangròs, J.J. Raventós, O. Rodríguez, compartides amb l’App FLOODUP).

El temporal de llevant va provocar altres conseqüències com un fort temporal de mar que va produir afectacions a les platges de gran part del Mediterrani espanyol, com a les de les províncies d’Alacant o Màlaga, produint inundacions de carrers i locals prop de la franja marítima i destrosses en alguns passeigs marítims. Al municipi de Mont-Roig del Camp es va produir un tornado que va malmetre teulades, arbres i faroles.


Ofertes de postdoc





More information in: HYMEX