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Climate sciences foresee a future where extreme weather events could happen with increased frequency and strength, which would in turn increase risks of floods (i.e. the main source of losses in the world). The Mediterranean basin is considered a hot spot in terms of climate vulnerability and risk. The expected impacts of those events are exacerbated by land-use change and, in particular, by urban growth which increases soil sealing and, hence, water runoff. The ultimate consequence would be an increase of fatalities and injuries, but also of economic losses in urban areas, commercial and productive sites, infrastructures and agriculture. Flood damages have different magnitudes depending on the economic value of the exposed assets and on level of physical contact with the hazard. This work aims at proposing a methodology, easily customizable by experts' elicitation, able to quantify and map the social component of vulnerability through the integration of earth observation (EO) and census data with the aim of allowing for a multi-temporal spatial assessment. Firstly, data on employment, properties and education are used for assessing the adaptive capacity of the society to increase resilience to adverse events, whereas, secondly, coping capacity, i.e. the capacities to deal with events during their manifestation, is mapped by aggregating demographic and socio-economic data, urban growth analysis and memory on past events. Thirdly, the physical dimension of exposed assets (susceptibility) is assessed by combining building properties acquired by census data and land-surface characteristics derived from EO data. Finally, the three components (i.e. adaptive and coping capacity and susceptibility) are aggregated for calculating the dynamic flood vulnerability index (FVI). The approach has been applied to Northeast Italy, a region frequently hit by floods, which has experienced a significant urban and economic development in the past decades, thus making the dynamic study of FVI particularly relevant. The analysis has been carried out from 1991 to 2016 at a 5-year steps, showing how the integration of different data sources allows to produce a dynamic assessment of vulnerability, which can be very relevant for planning in support of climate change adaptation and disaster risk reduction. [ABSTRACT FROM AUTHOR]

When floods hit inhabited areas, great losses are usually registered in terms of both impacts on people (i.e., fatalities and injuries) and economic impacts on urban areas, commercial and productive sites, infrastructures, and agriculture. To properly assess these, several parameters are needed, among which flood depth is one of the most important as it governs the models used to compute damages in economic terms. This paper presents a simple yet effective semiautomatic approach for deriving very precise inundation depth. First, precise flood extent is derived employing a change detection approach based on the normalized difference flood index computed from high-resolution synthetic aperture radar imagery. Second, by means of a high-resolution lidar digital elevation model, water surface elevation is estimated through a statistical analysis of terrain elevation along the boundary lines of the identified flooded areas. Experimental results and quality assessment are given for the flood that occurred in the Veneto region, northeastern Italy, in 2010. In particular, the method proved fast and robust and, compared to hydrodynamic models, it requires sensibly less input information. [ABSTRACT FROM AUTHOR]

This article presents a novel methodology to assess flood risk to people by integrating people's vulnerability and ability to cushion hazards through coping and adapting. The proposed approach extends traditional risk assessments beyond material damages; complements quantitative and semi-quantitative data with subjective and local knowledge, improving the use of commonly available information; and produces estimates of model uncertainty by providing probability distributions for all of its outputs. Flood risk to people is modeled using a spatially explicit Bayesian network model calibrated on expert opinion. Risk is assessed in terms of (1) likelihood of non-fatal physical injury, (2) likelihood of post-traumatic stress disorder and (3) likelihood of death. The study area covers the lower part of the Sihl valley (Switzerland) including the city of Zurich. The model is used to estimate the effect of improving an existing early warning system, taking into account the reliability, lead time and scope (i.e., coverage of people reached by the warning). Model results indicate that the potential benefits of an improved early warning in terms of avoided human impacts are particularly relevant in case of a major flood event. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses articles in the issue on topics including climate change, flood risk management and integrated water resources management.

Water-related disasters have caused increasing losses in recent years. Efficient risk reduction policies require accurate assessment approaches, with careful consideration of costs, beyond material damages, which are commonly used in practice. Faced with possible risk reduction scenarios, limited financial resources require an improvement in the quality of cost estimation, thereby contributing to an efficient allocation of resources. This paper reviews the concept of total cost in the context of water-related disasters, elaborating on the typical direct/indirect and tangible/intangible cost categories. These categories are defined and explained, supported by a comprehensive assessment of economic valuation methods. Based on this information, practice relevant suggestions are made concerning the most appropriate methods for different cases in terms of scale, availability of data and of technical resources. [ABSTRACT FROM AUTHOR]

Abstract: A methodological proposal aimed at improving the effectiveness of interactions between the scientific community and local actors for decision-making processes in water management was developed and tested to two case studies, in Europe and Asia: the Upper Danube (Danube) and Upper Brahmaputra (Brahmaputra) River Basins. The general objectives of the case studies were about identifying and exploring the potential of adaptation strategies to cope with flood risk in mountain areas. The proposal consists of a sequence of steps including participatory local workshops and the use of a decision support systems (DSS) tool. Workshops allowed for the identification of four categories of possible responses and a set of nine evaluation criteria, three for each of the three pillars of sustainable development: economy, society and the environment. They also led to the ranking of the broad categories of response strategies, according to the expectations and preferences of the workshop participants, with the aim of orienting and targeting further activities by the research consortium. The DSS tool was used to facilitate transparent and robust management of the information, the implementation of multi criteria decision analysis and the communication of the outputs. The outcomes of the implementation of the proposed methods and DSS tool are discussed to assess the potential to support decision-making processes in the field of climate change adaptation (CCA) and integrated water resources management (IWRM). [Copyright &y& Elsevier]