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Coastal risks in the Mediterranean are a result of the complex interplay between hydrometeorological and marine hazards. The region encompasses areas with varying degrees of vulnerability to these hazards, as well as spatial variations in exposure values, making it essential to adopt a comprehensive and nuanced approach to risk assessment and management. It is worth noting that hydrometeorological hazards, such as flash floods, can often have a greater impact than strictly coastal hazards, highlighting the need to consider the full range of potential risks. Therefore, coastal managers must adopt a multi-hazard approach to make sound risk management decisions. This study addresses this need using an index-based framework that assesses the integrated risk in time and space (hereafter referred to as cumulative compound risk) in coastal zones by aggregating the main hydrometeorological and marine hazards, the vulnerability of the territory to both types of hazards, and values at exposure. The framework is designed for use at large spatial scales (applied to a 1100 km coastline in this study), with the basic spatial unit being relevant for management (here set as the municipality in this study). Its application enables the assessment of spatial variations in integrated risk as well as individual hydrometeorological and marine contributions. The combined use of the indices and cluster analysis helps identify similarities and differences in the risk profile of spatial units, and thus, define homogeneous areas from a risk management perspective. In this study, the framework was applied to the Spanish Mediterranean coastline, an area representative of the climatic, geomorphological, and socioeconomic conditions of the Mediterranean coast. [ABSTRACT FROM AUTHOR]

Summary The aim of this paper is to analyse the potential relationship between flash flood events and convective precipitation in Catalonia, as well as any related trends. The paper starts with an overview of flash floods and their trends in the Mediterranean region, along with their associated factors, followed by the definition of, identification of, and trends in convective precipitation. After this introduction the paper focuses on the north-eastern Iberian Peninsula, for which there is a long-term precipitation series (since 1928) of 1-min precipitation from the Fabra Observatory, as well as a shorter (1996–2011) but more extensive precipitation series (43 rain gauges) of 5-min precipitation. Both series have been used to characterise the degree of convective contribution to rainfall, introducing the β parameter as the ratio between convective precipitation versus total precipitation in any period. Information about flood events was obtained from the INUNGAMA database (a flood database created by the GAMA team), with the aim of finding any potential links to convective precipitation. These flood data were gathered using information on damage where flood is treated as a multifactorial risk, and where any trend or anomaly might have been caused by one or more factors affecting hazard, vulnerability or exposure. Trend analysis has shown an increase in flash flood events. The fact that no trends were detected in terms of extreme values of precipitation on a daily scale, nor on the associated ETCCDI (Expert Team on Climate Change Detection and Indices) extreme index, could point to an increase in vulnerability, an increase in exposure, or changes in land use. However, the summer increase in convective precipitation was concentrated in less torrential events, which could partially explain this positive trend in flash flood events. The β parameter has been also used to characterise the type of flood event according to the features of the precipitation. The highest values correspond to short and local events, usually with daily β values above 0.5, while the minimum threshold of daily β for catastrophic flash floods is 0.31. [ABSTRACT FROM AUTHOR]

The analysis of both observed climate and fire data from 1970 to 2007 in a typical Mediterranean environment (i.e., the North-eastern Iberian Peninsula) shows that the warming climate forcing alone would have led to a positive trend in the Number of Fires (NF) and a slightly negative trend in the Burned Area (BA) in summer. This is in contrast to the common expectation that warming should result in larger fires. In fact, for BA, probably less favourable conditions for both fine fuel availability and fuel connectivity counterbalance the increase in fuel flammability. Climate projections from the ENSEMBLES Project indicate that warming will continue up to at least 2050, promoting more numerous fires but of similar or slightly smaller extension. These results suggest the necessity for a more intense fire management effort in order to maintain the number of fires at least at the same level as today. [ABSTRACT FROM AUTHOR]

The present paper shows an in-depth analysis of the evolution of floods and precipitation in Catalonia for the period 1981–2010. In order to have homogeneous information, and having in mind that not gauge data was available for all the events, neither for all the rivers and stream flows, daily press from a specific newspaper has been systematically analysed for this period. Furthermore a comparison with a longer period starting in 1900 has been done. 219 flood events (mainly flash flood events) have been identified for the period of 30 years (375 starting in 1900), 79 of them were ordinary, 117 of them were extraordinary and 23 of them were catastrophic, being autumn and summer the seasons with the maxima values. 19% of the events caused a total of 110 casualties. 60% of them died when they tried to cross the street or the stream. Factors like the evolution of precipitation, population density and other socio-economical aspects have been considered. The trend analysis shows an increase of 1 flood/decade that probably has been mainly due to inter-annual and intra-annual changes in population density and in land-use and land-cover. [ABSTRACT FROM AUTHOR]

Abstract: The main objective of the present paper is to show a methodology for undertaking rainfall regionalization of a region taking into account the convective features of the precipitation, and useful for establishing homogeneous zones for improving the alert system. This methodology has been applied to a hydrographic region located in northeast Spain, with an area of 16000 km2 and characterized by a highly contrasted topography. Information provided by meteorological radar and 5-min precipitation data for 126 automatic raingauges has been used for the period 1996–2002. The previous analysis done on the basis of the 1927–1981 rainfall rate series for the Jardí raingauge, located in Barcelona, has also been considered. To that end, the first step was to draw up a proposal for classification of the pluviometric episodes. Recourse was had for this purpose to definition of the β parameter, related with the greater or lesser convective character of the event and calculated on the basis of the rainfall intensity at the surface () and, when data are available, on the basis of radar reflectivity. Results show that the threshold of 35 mm/h to characterize convective episodes from raingauge data can be corroborated from the radar point of view when convective precipitation is identified using 2-D algorithms with a reflectivity threshold of 43 dBZ. Once the soundness of the β parameter had been corroborated, it was applied to more than 2900 precipitation episodes recorded in the region, in order to discriminate the features of the different subregions and their time and space distribution throughout the entire series of the samples. Using this definition, 92% of the precipitation events recorded in this region, with accumulated rainfall above 35 mm, are classified as convective ones, representing 95% of the precipitation amount. Application of the β parameter combined with monthly rainfall data allows differentiation of 8 regions with different convective precipitation features. [Copyright &y& Elsevier]

Abstract: The aim of this paper is to show a climatology of Mesoscale Convective Systems (MCS) in the NE of the Iberian Peninsula, on the basis of meteorological radar observations. Special attention was paid to those cases that have produced heavy rainfalls during the period 1996–2000. Identification of the MCS was undertaken using two procedures. Firstly, the precipitation structures at the lowest level were recognised by means of a 2D algorithm that distinguishes between convective and non-convective contribution. Secondly, the convective cells were identified using a 3D procedure quite similar to the SCIT (Storm Cell Identification and Tracking) algorithm that looks for the reflectivity cores in each radar volume. Finally, the convective cells (3D) were associated with the 2D structures (convective rainfall areas), in order to characterize the complete MCS. Once this methodology was presented the paper offers a proposal for classifying the precipitation systems, and particularly the MCS. 57 MCS structures were classified: 49% of them were identified as linearly well-organised systems, called TS (39%), LS (18%) and NS (43%). In addition to the classification, the following items were analysed for each MCS found: duration, season, time of day, area affected and direction of movement, and main radar parameters related with convection. The average features of those MCS show an area of about 25000 km2, Z max values of 47 dBz, an echotop of 12 km, the maximum frequency at 12 UTC and early afternoon and a displacement towards E-NE. The study was completed by analysing the field at surface, the presence of a mesoscale low near the system and the quasi-stationary features of three cases related with heavy rainfalls. Maximum rainfall (more then 200 mm in 6 h) was related with the presence of a cyclone in combination with the production of a convective train effect. [Copyright &y& Elsevier]

The communication presents the main results of the Spanish Project HOPE (CGL2014-52571-R). It treats flooding from a holistic perspective that integrates bottom-up and top-down approaches to improve the estimates of the present and future impacts of floods in the Eastern of the Iberian Peninsula and for designing proposals to improve the resilience and adaptation strategies. In a first phase, the project has systematically collected all the state of the art about legislation, procedures and criteria related with floods in France, Italy and Spain, as well as in the sub-national regions, which has been completed with scientific literature about flood risk impacts and flood risk trend. The study shows explicitly the problems associated to different criteria and definitions. Hydrometeorological and socioeconomic information associated to floods recorded between 1981 and 2015 in Catalonia, Valencia and Balearic Islands has been collected. This part has been developed in collaboration with the HYMEX program. Results show 258, 112, 47 flood events for these three regions respectively. Some of these events have affected more than one region, which means a total of 373 different flood and heavy rainfall events. Trend analysis has showed an increase of extraordinary flood events but not an increase in daily extremes of precipitation. On the contrary, the work with sub-daily data has showed a pattern characterised by an increase of convective precipitation in some coastal areas. The identification of precipitation and flow thresholds associated to different types of flood events and weather types has been done. Scenarios do not provide a good estimation of sub-daily precipitation, which forces us to work with daily data. Attending the fact that the greatest part of flood events is flash-floods produced by local and short but heavy precipitations, floods can be produced even if daily precipitation isn't high. Then, we have looked for the 30-min and 24-h precipitation for each event and we have reached the conclusion that more than 40 mm/day can have a potential flood risk in little basins. Weather types show a major contribution from situations associated to cyclones in surface.To analyse flood impacts, data from the re-insurance company of the Spanish State have been used to model the potential correlation between rainfall and damages. Data from discharge are not usually available since these are often non-gauged catchments. Results show a good correlation between 30-min maximum rainfall intensity in each event and damages. This has been used to stablish a logistic model relating rainfall and damages. The same methodology has been applied to maximum daily rainfall. Future scenarios from EURO-CORDEX have been applied to estimate future impacts.A last part consists in the holistic analysis of specific events like those floods produced in September 1962, November 1982, June 2013 and October 2016. Rainfall data produced by SAFRAN reanalysis, radar and lightning data and proxy-data to estimate discharge have been used. Results from the HOPE project have constituted the starting point of the National project CTM2017-83655-C2-2-R, M-CostAdapt, where adaptation strategies to climate change and risks in coastal Mediterranean Areas are analysed. [ABSTRACT FROM AUTHOR]

Nowcasting tools using radar data are essential when researching severe weather phenomena. Identifying thunderstorms and characterising their properties are usually the main steps to follow in order to make a good short-term forecast. These analyses are normally used to feed early warning systems in many countries, helping to reduce the impact of severe weather. Over the last few decades, research in this meteorological field has increased significantly, defining different methodologies that have worked well for many severe events. Most of these methodologies are based on a prior 3D identification of the thunderstorms in question, by applying intensity and size thresholds and obtaining their characteristics, allowing their centroids to be tracked. In some cases, the thresholds for identification and the distance established to track the centroid are too restrictive, which results in the incorrect identification of individual cells in multicell systems, or even means that the algorithm is unable to distinguish when an anomalous movement takes place. This paper presents a new type of 3D cell identification and tracking, based on the algorithm developed by Rigo and Llasat (2004). This last algorithm is currently used in the Meteorological Service of Catalonia (SMC), and consists of a nowcasting methodology based on centroid tracking. In the new version, a new two-step methodology to construct 3D radar cells has been proposed. A double reflectivity thresholding method plus an overlapping technique have been applied for a better definition of the convective structures. This makes it possible to identify possible changing processes such as splitting or merging within the same thunderstorm. Furthermore, a dynamic distance threshold technique has been adopted to correctly track cells with anomalous movements. An in-depth study has been carried out for a severe weather case in which a multicell system presented a complex merging and splitting process that was correctly forecasted using the proposed algorithm. [ABSTRACT FROM AUTHOR]

The growth of air transport demand expected over the next decades, along with the increasing frequency and intensity of extreme weather events, such as heavy rainfalls and severe storms due to climate change, will pose a tough challenge for air traffic management systems, with implications for flight safety, delays and passengers. In this context, the Satellite-borne and IN-situ Observations to Predict The Initiation of Convection for ATM (SINOPTICA) project has a dual aim, first to investigate if very short-range high-resolution weather forecast, including data assimilation, can improve the predictive capability of these events, and then to understand if such forecasts can be suitable for air traffic management purposes. The intense squall line that affected Malpensa, the major airport by passenger traffic in northern Italy, on 11 May 2019 is selected as a benchmark. Several numerical experiments are performed with a Weather Research and Forecasting (WRF) model using two assimilation techniques, 3D-Var in WRF Data Assimilation (WRFDA) system and a nudging scheme for lightning, in order to improve the forecast accuracy and to evaluate the impact of assimilated different datasets. To evaluate the numerical simulations performance, three different verification approaches, object-based, fuzzy and qualitative, are used. The results suggest that the assimilation of lightning data plays a key role in triggering the convective cells, improving both location and timing. Moreover, the numerical weather prediction (NWP)-based nowcasting system is able to produce reliable forecasts at high spatial and temporal resolution. The timing was found to be suitable for helping Air Traffic Management (ATM) operators to compute alternative landing trajectories. [ABSTRACT FROM AUTHOR]

Despite the current developments in flood forecasting and emergency management, floods still consist a significant threat to people and properties. At a national level in Europe, data on flood fatalities are fragmentary and they are mainly focused on death toll, without providing further details regarding victims' characteristics or the circumstances under which the deadly events have taken place. However, such details could enlighten us on what happened wrong when there was a victim due to a flood, and what measures should be taken in order to avoid similar events in the future. This paper presents the EUFF 2020 database (EUropean Flood Fatalities-FF) (EUropean Flood Fatalities-FF) (https://doi.org/10.4121/uuid:489d8a13-1075-4d2f-accb-db7790e4542f, Petrucci et al., 2020) which collects data from 2483 flood deadly cases occurred in a 39-year period (1980-2018) in 8 countries and 9 (two belong in Spain) study areas (Czech Republic, Israel, Italy, Turkey, Greece, Portugal, South France, Catalonia and Balearic Islands). EUFF 2020 (Petrucci et al., 2020) attempts to shed light on fatal flood events in the Euro-Mediterranean region under various geomorphological and climatic settings. The paper presents both regional and super-regional analyses from gender, age, conditions, activity of fatalities and dynamics of the accidents point of view aiming to contribute to a better understanding of the population exposure to floods phenomena. The historical research, which was carried out by using local documentary sources, highlights that 64.8 % of FF have been due to flood events in which less than 10 people were killed. Due to this relatively small number of losses, these events have not been recorded in the international disaster databases. Flood events causing single and multiple fatalities occurred throughout the period of our analysis without showing any particular remarkable trend. Data confirm that victim's gender only, is not a de facto driver of social vulnerability. In addition, females flood fatalities are quantitatively more than males. Males' vulnerability depends on a stronger exposure to floods, due to the higher proportion of males driving vehicles, doing outdoorsworking activities and sometimes undertaking risky actions. The majority of fatalities are people in their most productive working age (between 30 and 64 years old), who are exposed to floods outdoor while heading from home to work or vice-versa. Elderly people (in status of retirement) seem to be more frequently affected while being indoor, trapped by the flood in their premises, while adults and children are dragged outdoors. Driving car or any other kind of vehicles are the most frequent conditions of victims in all studied areas, for both males and females, as widely stated in literature. The EUFF 2020 database can be extended spatially and temporally, and it represents a European database of high scientific and practical potential for further use in various scientific disciplines. We hope, EUFF 2020 database will further motivate researchers to enrich with even more data on flood fatalities from their home countries. Spatial extension will allow the comparison of local frameworks in broader European scale and the identification of useful general and local features of risk management and educational campaigns. We believe that the followed pan-European approach, frames the anticipation of flood fatality risk into a broader context, promising benefit for diverse scientific disciplines and contributing to public policies and civil protection campaigns in order to reduce the number of floods' fatalities in the future. [ABSTRACT FROM AUTHOR]

In this paper, we assess and develop a climate service focused on the production of seasonal predictions for summer wildfires in a Mediterranean region through a participatory approach with end-users. We start by building a data-driven model that links a drought indicator (Standardised Precipitation Evapotranspiration Index; SPEI) with a series of burned areas in Catalonia (northeastern Spain). Afterwards, we feed this model with SPEI forecasts obtained through a combination of the antecedent observed conditions and climatology. Finally, we assess the forecasting skill of the system by using cross-validation to evaluate the predictions as if they had been made operationally. Our fire forecasting system reveals an untapped and useful burned area predictive ability. We argue that this source of predictability is mostly attributable to the effect of observed initial conditions on summer drought conditions. This system was conceived with the stakeholders, merging climate-driven predictions with information that is of interests to the users, including the identification of climate variables, thresholds and models. The co-production of this customized system allows fire-risk outlooks to be translated into usable information for fire management. This fire forecasting ability plays a crucial role in developing proactive fire management practices such as long-term fuel assessment and other fire-risk planning, thus minimising the impact of adverse climate conditions on summer burned area. Unlabelled Image • A climate service for seasonal predictions for summer wildfires is proposed. • Logistic regression models linking drought and fire variables are defined. • Persistence-based drought forecasts feed this data-driven fire model. • Summer fires can be forecast months in advance with this strategy. • The co-production of this system is key to providing usable information. [ABSTRACT FROM AUTHOR]

The article focuses on the Distributed Research Infrastructure for Hydro-Meteorology to U.S. (DRIHM2US) project for analysis of High-Impact Weather Events (HIWE) in the U.S. Topics discussed include incorporation of distributed computing infrastructure (DCI) services for management of research services; provision of different services such as meteorological models through DCI issues; and consideration of multimodal approach for hydrometeorological forecasting.

Forest fires are a serious environmental hazard in southern Europe. Quantitative assessment of recent trends in fire statistics is important for assessing the possible shifts induced by climate and other environmental/socioeconomic changes in this area. Here we analyse recent fire trends in Portugal, Spain, southern France, Italy and Greece, building on a homogenized fire database integrating official fire statistics provided by several national/EU agencies. During the period 1985-2011, the total annual burned area (BA) displayed a general decreasing trend, with the exception of Portugal, where a heterogeneous signal was found. Considering all countries globally, we found that BA decreased by about 3020 km2 over the 27-year-long study period (i.e. about -66% of the mean historical value). These results are consistent with those obtained on longer time scales when data were available, also yielding predominantly negative trends in Spain and France (1974-2011) and a mixed trend in Portugal (1980-2011). Similar overall results were found for the annual number of fires (NF), which globally decreased by about 12600 in the study period (about -59%), except for Spain where, excluding the provinces along the Mediterranean coast, an upward trend was found for the longer period. We argue that the negative trends can be explained, at least in part, by an increased effort in fire management and prevention after the big fires of the 1980’s, while positive trends may be related to recent socioeconomic transformations leading to more hazardous landscape configurations, as well as to the observed warming of recent decades. We stress the importance of fire data homogenization prior to analysis, in order to alleviate spurious effects associated with non-stationarities in the data due to temporal variations in fire detection efforts. [ABSTRACT FROM AUTHOR]

Droughts can have strong environmental and socio-economic impacts in the Mediterranean region, in particular for countries relying on rain-fed agricultural production, but also in areas in which irrigation plays an important role and in which natural vegetation has been modified or is subject to water stress. The purpose of this review is to provide an assessment of the complexity of the drought phenomenon in the Mediterranean region and present various perspectives on drought in the present and under future climate change scenarios. The projections of various model experiments on future climate change scenarios strongly agree on an increased frequency and severity of droughts in the Mediterranean basin. Nevertheless, given the complexity of the phenomenon, with different types of droughts and complex interrelated impacts, significant future uncertainties remain. For example, uncertainties are stronger for hydrological droughts than meteorological droughts due to human influences and water withdrawal. Significant drought impacts are expected in the future, in particular for developing countries in the southern and eastern parts of the Mediterranean basin. To improve the resilience and adaptive capacities of societies and environments faced with drought, we aim to provide an overview of the key issues in research on climate change impacts on droughts, with a specific focus on the Mediterranean region, in order to: i) redefine more meaningful drought metrics tailored to the Mediterranean context, ii) better take into account vegetation and its feedback on droughts, iii) improve the modelling and forecasting of drought events through remote sensing and land surface models, and iv) promote a more integrated vision of droughts taking into account both water availability and water use. This overview reflects the complexity of the problem and the need to combine scientific research with adaptation solutions to deal with drought in the future. [ABSTRACT FROM AUTHOR]