Cartographie sectorielle et dynamique de la plaine alluviale du Rhône suisse (Tourtemagne-Sierre) depuis la fin du Petit Age Glaciaire

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Cartographie sectorielle du paléoenvironnement de la plaine alluviale du Rhône suisse depuis la fin du Petit Age Glaciaire : la métamorphose fluviale de Viège à Rarogne et de Sierre à Sion.

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The evolution of climate change guidance for fluvial flood risk management in England

Floods are one of the biggest natural hazards to society, and there is increasing concern about the potential impacts of climate change on flood occurrence and magnitude. Furthermore, flood risk is likely to increase in the future not just through increased flood occurrence, but also through socio-economic changes, such as increasing population. The extent to which adaptation measures can offset this increased risk will depend on the level of future climate change, but there exists an urgent need for information on the potential impacts of climate change on floods, so that these can be accounted for by flood management authorities and local planners aiming to reduce flood risk. Agencies across the UK have been pro-active in providing such guidance for many years and in refining it as the science of climate change and hydrological impacts has developed. The history of this guidance for fluvial flood risk in England is presented and discussed here, including the recent adoption of a regional risk-based approach. Such an approach could be developed and applied to flood risk management in other countries, and to other sectors affected by climate change

Climate change and river flooding: part 2 sensitivity characterisation for british catchments and example vulnerability assessments

This paper is the second of a series describing a scenario-neutral methodology to assess the sensitivity and vulnerability of British catchments to changes in flooding due to climate change. In paper one, nine flood sensitivity types were identified from response surfaces generated for 154 catchments. The response surfaces describe changes in 20-year return period flood peaks (RP20) in response to a large set of changes in precipitation, temperature and potential evapotranspiration. In this paper, a recursive partitioning algorithm is used to link families of sensitivity types to catchment properties, via a decision tree. The tree shows 85 % success characterising the four sensitivity families, using five properties and nine paths. Catchment annual average rainfall is the primary partitioning factor, with drier catchments having a more variable response to climate (precipitation) change than wetter catchments and higher catchment losses and permeability being aggravating factors. The full sensitivity-exposure-vulnerability methodology is illustrated for two catchments: sensitivity is estimated by using the decision tree to identify the sensitivity family (and its associated average response surface); exposure is defined from a set of climate model projections and combined with the response surface to estimate the resulting impacts (changes in RP20); vulnerability under a range of adaptive capacity thresholds is estimated from the set of impacts. Even though they are geographically close, the two catchments show differing vulnerability to climate change, due to their differing properties. This demonstrates that generalised response surfaces characterised by catchment properties are useful screening tools to quantify the vulnerability of catchments to climate change without the need to undertake a full climate change impact study. © 2013 Springer Science+Business Media Dordrecht