Sea Level Rise
Holding back the tide - sea's advance threatens Tunisia's beaches
By Layli Foroudi
HAMMAMET, Tunisia (Thomson Reuters Foundation) - The trunks of two palm trees lie flat on the white sand outside the Sultan Hotel in Hammamet, Tunisia, a stark sign of the rapid erosion this stretch of beach is suffering.
After a storm washed away the beach in 2006, the hotel's manager Mehdi Jallani imported 12,400 tons of sand from a nearby mountain quarry to restore. But initially that too kept getting washed away.
"It's very complicated to battle against mother nature," he said. "During the works, I put sand down, waves removed it. I put it down, it (was) removed. I put and I put and in the end it was ok."
Almost half Tunisia's 670 km (420 miles) of white sandy beaches are acutely threatened by coastal erosion, according to the Tunisian State Agency for Coastal Protection and Planning (APAL), more than three times the number identified in 1995.
The cause is a toxic mix of rising sea levels, construction and more extreme weather patterns exacerbated by climate change.
In the last five years, Tunisia had seen three "20-year storms", the kind that would previously have occurred only once every two decades, according to APAL.
'DROP IN THE OCEAN'
To fight erosion, APAL is building walls to protect the coastline from the waves and has sourced 1 million cubic metres of sand from a nearby sand quarry.
But rebuilding beaches requires a very specific type of sand, according to its technical director, Mohamed Ali Torki.
Only two beaches have so far been restored, yet reserves are already running low, and last August APAL launched a study to identify sand reserves in the sea.
"For the sand to be stable, it needs to be quartz, not carbon, of a certain granulometry, (and) desert sand is worth nothing because (the grains are) round, not angular," said Torki, explaining that it would wash away immediately.
The sand also has to be white, he said - local people insist on that.
Until now, APAL has protected just 32 km of coast. Some hotel owners have taken it on themselves to protect their own beaches, but intervening on one section of is not effective, said Torki.
"It is like a drop in the ocean," he told the Thomson Reuters Foundation.
The erosion is bad news for tourism, which accounts for 8% of Tunisia's gross domestic product and was hit by a militant attack targeting tourists that killed dozens of people in 2015.
The rate of increase has accelerated dramatically, from an average 0.7 mm (0.03 inches) per year between 1945 and 2000, to 3mm per year over the last 20 years, according to Semia Cherif, a professor at the University of Tunis.
But there is more to coastal erosion than sea level rise.
Essam Heggy, who has researched the impact of erosion on Hammamet Bay, said the very existence of tourist resorts in the area was accelerating the process.
That is because buildings physically prevent the sediment that helps form strong beaches from reaching the shore, making them less resilient.
That could lead to "an irreversible chain of reactions that can degrade groundwater and agriculture deep inland, impacting food security and employment," said Heggy.
His research shows the coastline of Hammamet Bay is retreating far faster than the global average - between 1.3 and 5.6 metres a year between 1952 and 2018.
Noomane Haouel, the director of maritime engineering firm MARITEC, said the ideal solution was a "managed retreat" from the coast.
That would be a huge task given the concentration of urban and economic development there.
Tunisia's official investment policy has favoured coastal regions and more than half of its people live in three cities by the sea, Tunis, Sfax and Sousse, according to 2014 World Bank Data.
In the coastal region of Nabeul, an hour's drive from Hammamet, orange farmers are feeling the impact of the sea's advance.
Adel Echandly first noticed more than a decade ago that his oranges were shrinking and the soil was covered in a white residue - salt.
Seawater intrusion has caused the groundwater in parts of Tunisia to become saltier, which experts say is destroying vegetation at a rapid rate.
"We can see how harmful salt is: the oranges become much smaller, the trees dry out, the leaves are tired and yellowed," said the 55-year-old, who owns five hectares of orange trees.
Echandly was advised to start buying from the dams in the north of the country when the water in his well became too saline. But the fresh water often wouldn't arrive until April, too late to irrigate.
In 2009, desperate for a solution as his production levels plummeted towards zero, he spent 40,000 Tunisian dinars ($14,000) - a third of his annual revenue - on a desalination machine.
That increased production from less than 5 tons per hectare to 35 tons per hectare.
But that solution is too expensive for most farmers and in any case it creates a saline waste product that is toxic for the soil, said Habib Ayeb, president of the Tunisian Observatory for Food Sovereignty and the Environment
"He (Echandly) is producing now, but his kids won't be able to," said Ayeb.