Periglacial environments and frozen ground in the central Pyrenean high mountain area: Ground thermal regime and distribution of landforms and processes

Producción CientíficaThe periglacial belt is located in the highest parts of temperate mountains. The balance between mean air and ground temperatures and the presence of water determine the effectiveness of periglacial processes related to permafrost, the active layer or seasonally frozen ground (SFG). This study combines thermal and geomorphological data obtained in four Pyrenean massifs (Infierno‐Argualas, Posets, Maladeta and Monte Perdido) to improve knowledge on the occurrence and distribution of frozen ground. The methodology used is based on the study of landforms as frozen ground indicators, mapping processes, ground temperature analysis, basal temperature of snow, thermal mapping and geomatic surveys on rock glaciers and protalus lobes. In the Pyrenean high mountain areas the lower limit of frozen ground is at ~2,650m a.s.l., possible permafrost appears above 2,650m a.s.l. on north‐ and south‐facing slopes, and probable permafrost is dominant above 2,900m a.s.l. Unfrozen ground with cold‐associated geomorphological processes reach 2,900m a.s.l. and unfrozen and frozen ground distribution points to a patchy pattern throughout the periglacial belt. The most widespread frozen grounds are SFG. The thermal data, mean annual ground temperature, cold season temperatures, bottom temperature snow measurements, freeze/thaw cycles and distribution of landforms permit the establishment of a periglacial land system divided into three main belts: infraperiglacial, middle periglacial and supraperiglacial. The large number of processes and landforms that are involved and their altitudinal and spatial organization make up a complex environment that determines the geoecological dynamics of high mountain areas.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (projects CGL2015-68144-R / GL2017- 82216-R

De la relocalisation à la recomposition territoriale : adapter l’approche aux risques côtiers

International audienceAbstract Studying the population’s perception of coastal erosion is essential and is increasingly used by coastal administrators, especially because it strongly influences the acceptance of coastal adaptation strategies. This article explores the population’s perception of coastal risk on the Atlantic coast of France (Pays de la Loire region) that is an at-risk territory historically affected by erosion and is particularly sensitive to coastal flooding. The major goal of the paper is to collect data in terms of risk perception by carrying out a field survey on three territorial collectivities, with the aim to enhance the feasibility of the managed retreat operations that will be implemented on this coast in the next years. A total of 700 surveys were collected and several original results can be drawn: the population has a good knowledge of erosion in the area where they live, and this knowledge is key because the territory is vulnerable. Similarly, the respondents have a good knowledge of protection measures, but some are more important than others: for example, the reinforcement of coastal defenses is the most commonly cited strategy to deal with coastal hazards whereas relocation is the second-most-known but least-popular scenario. Several factors influence people’s perception of risk: for example, time spent in the residence and age of residents are two elements contributing to place attachment that must be taken into account before starting to implement any climate adaptation policies

Coastal Erosion Risk: Population Adaptation to Climate Change A Case Study of the Pays de la Loire Coastline.

Abstract Studying the population's perception of coastal erosion is essential and is increasingly used by coastal administrators, especially because it strongly influences the acceptance of coastal adaptation strategies. This article explores the population’s perception of coastal risk on the atlantic coast of France (pays de la Loire region) that is an at-risk territory historically affected by erosion and particularly sensitive to coastal flooding. The major goal of the paper is to collect data in terms of risk perception by carrying out a field survey on three territorial collectivities, with the aim to enhance the feasibility of the managed retreat operations that will be implemented on this coast in the next years. A total of 700 surveys were collected and several original results can be drawn: the population has a good knowledge of erosion in the area where they live and this knowledge is key as the territory is vulnerable. Similarly, the respondents have a good knowledge of protection measures but some are more important than others: for example, the reinforcement of coastal defenses is the most commonly cited strategy to deal with coastal hazards while relocation is the second most known but least popular scenario. Finally, several factors influence people's perception of risk: for example, time spent in the residence and age of residents are two elements contributing to place attachment which must be taken into account before starting to implement any climate adaptation policies