Research by investigators at the University of the Balearic Islands (UIB), the University of Cadiz and the University of Huddersfield highlights the vital role that the first dune line has in the conservation of beaches.
A paper, Measurement of Surface Wind and Sediment Transport in a Dune System Environment, in the Journal of Marine Science and Engineering has examined in particular the 'blowout' phenomenon, the erosion channel located behind the first dune line.
When it hits the first dune line, wind loses strength and the sand-sediment it carries falls by gravity. Therefore, and this is the main conclusion of the study, this first dune line is of prime importance in preventing beach erosion. It is essential for guaranteeing the conservation of the beach-dune system. In short, with a dune front line in good condition, the beach has more resistance and recovers better after a storm.
One of the researchers is Miquel Mir, who was Balearic environment minister until June 2023. Now a professor of geography at UIB, he says that a well-conserved dune system always has a well-defined first line. "The results (of the study) are fundamental for good management of beaches in the Balearic Islands and in the rest of the world."
"Beaches in Mallorca with a first dune line in poor condition that has affected the entire dune system can be found at Es Comú in Muro, Cala Agulla, some areas of Es Trenc, Cala Millor and Santa Ponsa. On these last two beaches, as was also the case in Playa de Palma, the dune systems were destroyed by development immediately next to the beach. However, actions taken in Es Trenc to conserve its dune system and its first line, avoiding human frequentation in these areas, are giving results and there is now a collection of sand that is contributing to the recovery of the beach."
Another factor to take into account is the role of posidonia remains on the beaches. These are essential for beach conservation, especially after storms. The Balearic posidonia decree establishes criteria for the withdrawal of remains (or not). As to artificial regeneration of beaches, Mir believes: "These are useless actions, since storms end up taking away the sand that has been deposited and also the money invested."