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In a context of high uncertainty of hydro-climatic variables, the development of updated methods to assess climate change impacts is as important as the provision of improved climate change data. This article presents the impacts of climate change on the flooding problems concerning a critical area of Barcelona and the assessment of the effectiveness of structural and nonstructural measures to cope with such impacts. For this purpose, a specific study tackling climate change influence on extreme precipitation in Barcelona and a detailed 1D/2D-coupled model were used. Once the model was developed and calibrated, several scenarios of adaptation measures were considered to cope with climate change effects for the 2050 horizon. Results concerning these scenarios were compared to a defined 'business as usual scenario'. Climate change impacts were assessed in terms of flood hazard and risk maps concerning vehicular and pedestrian circulation for several return periods (1, 10 and 100 years) for all the considered scenarios. Additionally, direct tangible damages were estimated using depth-damage curves. The expected annual damage of the area is obtained by combining hazard and vulnerability levels using a Geographic Information System-based toolbox. By undertaking a cost-benefit analysis, the effectiveness of the strategies is assessed.

International audienceForest fire can modify and accelerate the hydrological response of Mediter-ranean basins submitted to intense rainfall: during the years following a fire, the effects on the hydrological response may be similar to those produced by the growth of impervious areas. Moreover, climate change and global warming in Mediterranean areas can imply consequences on both flash flood and fire hazards, by amplifying these phenomena. Based on historical events and post-fire experience, a methodology to interpret the impacts of forest fire in terms of rainfall-runoff model parameters has been proposed. It allows to estimate the consequences of forest fire at the watershed scale depending on the considered burned area. In a second stage, the combined effect of forest fire and climate change has been analysed to map the future risk of forest fire and their consequence on flood occurrence. This study has been conducted on the Llobregat river basin (Spain), a catchment of approximately 5,000 km 2 frequently affected by flash floods and forest fires. The results show that forest fire can modify the hydrological response at the watershed scale when the burned area is significant. Moreover, it has been shown that climate change may increase the occurrence of both hazards, and hence, more frequent severe flash floods may appear