Prevention of Major Natural Risks in Arcachon Basin

Extract

[...] Actions of the public authorities Answers to the question 'Are you aware of any arrangements that have been put in place to limit these risks?' Only of those questioned were unaware of any arrangements put in place: this shows a relatively good consideration of the residents' measures and their interest in this subject. Most cited the breakwater, due to their visibility and omnipresence on the beaches. Some also mentioned the dunes, as listed earlier, as well as the plantations (Pines in particular). These responses should be put into perspective with the origin of the people questioned. [...]

[...] There are notably informative panels in public spaces, accessible at all times by users, but whose limit lies in their lack of interactivity. It is also possible to place physical markers to show the level of historical submersions, allowing for the creation of a local anchor of the problem and to better understand it. Pedagogy should also be developed in schools, which will also improve the knowledge that children have of their territory and their sense of belonging. Finally, good practices should be communicated to residents so that they know how to limit or face the risks (how to react in case of submersion, how to enjoy the forest without putting it in danger, etc.). [...]

[...] Means of prevention of major natural risks on the territory of the Arcachon Basin - Analysis of results Step Analysis of results A. Means of existing prevention in the Arcachon Basin Through field observations, I was able to observe several means of prevention of various natures including: - Hydraulic developments: locks, ditches, barbacans, dikes, protection walls, etc. - Natural infrastructure: old fish reservoirs, salt pans, dunes, etc. Here is an inventory of the main developments observed during these observations: Localisation Means of prevention Impacts Commune GPS Coordinates Type Utility Negative Externalities / Limits La Teste-de-Buch - Johnston Dam 44°38'44.3"N 1°08'48.2"W Dam - Limit the risk of marine flooding - Maintain the existence of the pedestrian path - Preserve the natural space - Probability of failure - Exacerbate the gap between the rising sea level and the subsiding land level The Pond 44°38'29.2"N 1°01'10.2"W Biganos et Audenge 44°39'40.0"N 1°00'54.8"W Digues de bassins Lanton 44°41'56.0"N 1°02'41.3"W Are?s 44°46'00.2"N 1°09'03.6"W Andernos-les-Bains 44°43'40.2"N 1°05'16.2"W Muret - Fighting against erosion - Probability of rupture Le?ge-Cap Ferret : the Pointe 44°37'22.7"N 1°15'22.0"W Natural Barrier - Natural Adaptation to Marine Erosion - Subject to a natural dynamic: in regression Le?ge-Cap Ferret: The Mimbeau 44°38'14.8"N 1°14'35.1"W Observation Grid Personal photos to add if possible B. [...]

[...] Strengthening of infrastructure The infrastructure put in place aims to reduce the vulnerability of the basin. Beyond the infrastructure already in place studied earlier, we can identify two axes of improvement. Firstly, establishing a relationship with real estate developers for better resilience of new dwellings and taking into account the risks in the choice of implantation, in connection with urban planning documents (cartography of submersion, land movement and fire risks). Secondly, an identification of buffer zones, with a measurement of their storage capacities. [...]

[...] They can also show a lack of centralization of information with a risk of repetition or contradictions. C. Perspectives a. Improvement of knowledge The prediction and monitoring of hazards allow us to be aware of the evolution of risks. One of the tools used is for example the SEAMAFOR platform, an oceanography information platform. To feed these tools, field observations remain essential. This is why it is imperative to develop the webcam network on the coast to have a regular and extensive follow-up of the evolution of the coastline and the level of submersion. [...]