Hyères saltworks
Exploring the origins of the saltworks
Until the 19th century, these saltworks served as a fishing ground where fish were caught in the lagoon by entering through passages at the tombolo borders. In 1850, the area was transformed into saltworks for chemical and road infrastructures purposes. All around the saltworks, a canal was built to prevent fresh water to spill in the site and dilute sea water. In addition this canal was a physical barrier to control salt output streams and to ensure tithe payment.
Today...
The saltworks represent one of the only coastal wetlands in the Western Mediterranean, alongside the Camargue and the Po delta in Italy. Moreover, these sites are home to nearly 327 bird species, including 30 nesting species, most of which are heritage species. The bird breeding season extends from March, with the arrival of the first migratory birds from Africa, until July.
Giens peninsula
Giens peninsula is linked to the continent by a structure called double tombolo. Tombolos are natural but rare bridges connecting an island and a continent, only shaped under very specific circumstances such as specific ocean currents, continent-island distance, island length etc. When two bridges occur, it is called a double tombolo, and even triple tombolo can form under very strict conditions.
Sand beach formation
Tombolos shaping involve beach and sand formation. Sand is essentially made of quartz grains. This quartz is brought from mountain ranges after being eroded by wind and water. Later transported by water streams and rivers, the sand accumulates at estuary level. Eventually, the sand is spread all along coasts by waves coming from the open sea.
When an island is close enough to coasts and oceanic/geographic conditions are suitable, waves from both side of the island gather sand to the center, leading to a tombolo that reach mainland.