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The objective of this paper is to examine how current techniques for flashflood monitoring and forecasting can meet the needs of the population at risk to evaluate the flood severity and anticipate its danger. To this end, the social response time for different social actions in the course of two well studied flash flood events which occurred in France and Italy is identified. The event management activities are broadly characterized into three types according to their main objective information, organisation and protection. The activities are also classified into three other types according to the scale and nature of the human group involved individuals, communities and institutions. The conclusions reached relate to 1 the characterisation of the social responses according to watershed scale and to the information available, and 2 to the appropriateness of the existing surveillance and forecasting tools to support the social responses. Results suggest that representing the dynamics of the social response with just one number representing the average time for warning a population is an oversimplification. It appears that the social response time exhibits a parallel with the hydrological response time, by diminishing in time with decreasing size of the relevant watershed. A second result is that the human groups have different capabilities of anticipation, apparently based on the nature of information they use. Comparing watershed response times and social response times shows clearly that at scales of less than 100 km2, a number of actions were taken with response times comparable to the catchment response time. The implications for adapting the warning processes to social scales individual or organisational scales are considerable. At small scales, and for the implied anticipation times, the reliable and highresolution description of the actual rainfall field becomes the major source of information for decisionmaking processes such as deciding between evacuations or advising to stay home. This points to the need to improve the accuracy and quality control of real time radar rainfall data, especially for extreme flash floodgenerating storms. Copyright © 2009 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

The article describes the attempt to include the intensityscale technique introduced by Casati et al. 2004 into a set of standardized verifications used in operational centres. The intensityscale verification approach accounts for the spatial structure of the forecast field and allows the skill to be diagnosed as a function of the scale of the forecast error and intensity of the precipitation events. The intensityscale method has been used to verify two different resolutions of the European Centre for MediumRange Weather Forecasts ECMWF operational quantitative precipitation forecast QPF over France, and to compare the performance of the ECMWF and the Hungarian Meteorological Service operational model ALADIN forecasts, run over Hungary. Two case studies have been introduced, which show some interesting insight into the spatial scale of the error. The distribution of daily skill score for an extended period of time is also presented. The intensityscale technique shows that the forecasts in general exhibit better skill for largescale events, and lower skill for smallscale and intense events. In the paper, it is mentioned how some of the stringent assumptions on the domain over which the method can be applied, and the availability of the matched forecasts and observations, can limit its usability in an operational environment. Copyright © 2008 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

Groundwater recharge depends generally on precipitation. In this study, a geographical information system (GIS) procedure was applied to assess the climate change effect on groundwater recharge in the Grand Est region of France. The analysis comprises high‐resolution climate models that reflect the long‐term climatological regime. The hydrological properties include aquifers, land‐cover and terrain morphology data, which were used to develop the potential infiltration map of the study area. Two parameters, the De Martonne aridity index and effective precipitation, were combined into a 5 × 5 matrix to assess the climate change effect on groundwater recharge during the past (1990s), present (2020s) and future (2050s) periods. The present and future intense aridization and the depletion of the effective precipitation (< 650 mm) reveal the negative effects of climate change on aquifers' recharge in the Grand Est region. The areas with high and very high climate effects will increase in the 2020s and 2050s. These areas extend mainly in the western, north‐central and northeastern parts of the region occupying the Rhine, Aube and Marne valleys. The medium effect could be found in the central, southern and northwestern parts, while the low impact on groundwater recharge was verified in the northwestern and southeastern parts of the region. The area with low effects of climate change extends mostly in the Vosges and Ardennes mountains. These findings contribute to the long‐term hydrogeological studies in the Grand Est region. [ABSTRACT FROM AUTHOR]