Review article: assessing the costs of natural hazards - state of the art and knowledge gaps

Efficiently reducing natural hazard risks requires a thorough understanding of the costs of natural hazards. Current methods to assess these costs employ a variety of terminologies and approaches for different types of natural hazards and different impacted sectors. This may impede efforts to ascertain comprehensive and comparable cost figures. In order to strengthen the role of cost assessments in the development of integrated natural hazard management, a review of existing cost assessment approaches was undertaken. This review considers droughts, floods, coastal and Alpine hazards, and examines different cost types, namely direct tangible damages, losses due to business interruption, indirect damages, intangible effects, and the costs of risk mitigation. This paper provides an overview of the state-of-the-art cost assessment approaches and discusses key knowledge gaps. It shows that the application of cost assessments in practice is often incomplete and biased, as direct costs receive a relatively large amount of attention, while intangible and indirect effects are rarely considered. Furthermore, all parts of cost assessment entail considerable uncertainties due to insufficient or highly aggregated data sources, along with a lack of knowledge about the processes leading to damage and thus the appropriate models required. Recommendations are provided on how to reduce or handle these uncertainties by improving data sources and cost assessment methods. Further recommendations address how risk dynamics due to climate and socio-economic change can be better considered, how costs are distributed and risks transferred, and in what ways cost assessment can function as part of decision support

INSERTION OF FeCl4-, AlCl4- AND HSO4- IONS INTO POLYACETYLENE - STUDY OF THE REACTION CONDITIONS AND PROPERTIES OF THE PRODUCTS

L'insertion électrochimique de FeCl4- et AlCl4- dans le polyacétylène est décrite. Les tétrachloroferrates de polyacétylène sont beaucoup plus stables à l'air que les tétrachloroaluminates de polyacétylène. L'insertion chimique de HSO4- est aussi reportée ainsi que les mécanismes de réaction de l'eau avec les hydrogénosulfates de polyacétylène obtenus.The electrochemical intercalation of FeCl4- and AlCl4- ions into polyacetylene is reported. After exposure to air, polyacetylene tetrachloroferrates are much more stable than polyacetylene tetrachloroaluminates. The chemical intercalation of HSO4- into polyacetylene from H2SO4 vapours is described. The action of water on the polyacetylenehydrogensulfates formed is discussed