The geography of Arcachon

When we mention the name of Arcachon, we have two things in mind: the French town of the subprefecture of the Gironde and the lagoon of the Arcachon basin. In this article, we will speak more precisely of the second category by developing its geographical attractions which make of  the lagoon, one of the most appreciated sites of France.

The Arcachon basin is indeed an expanse of seawater located between the mainland and the littoral cordon with one or more passes. This impressive formation dates from the years 400 BC during the Neolithic periods. The river Eyre, at that time, flowed directly into the sea through an estuary. The height of the water was still very low, which was served as a place for the creation of lagoons, and did not appear until the Gallo-Roman period.

With the addition of sediments, the flow of the Eyre has considerably weakened, causing the formation of an area of ​​delta consisting of islands and channels. The peninsula of Cap-Ferret then developed in the Middle Ages with the displacement of sand dunes to the south.

Today, the Arcachon Basin consists of 18,300 ha of water at high tide, 5,000 ha of stretch of water at low tide, about 20 m deep and 4 m of the tidal range of white water. Salty meadows are amongst others fine parts of the Bassin d'Arcachon forming a transitional space between the Delta de l'Eyre and the wetland of the basin.

Salted meadows are, among other things heavily covered during the rise of high of water, so they are composed of specifically abundant and diverse vegetation and fauna. The entire ecosystem is partly preserved by the Ramsar Convention on Wetlands. The Bassin d'Arcachon is located in the Pays de Buch and is located in the heart of the Landes de Gascogne, halfway between Grave and Cape Breton.