Madison Heard

Israeli scientists work to save the country’s coastline from rising tide

June 4, 2020

Ancient escarpments along Israel’s coast are being broken down by the constant wave action while the sea level rises and beaches disappear. What does this mean for Israel’s changing coastline?

The Israeli coastline has been changing for centuries, and the prehistoric evidence can be seen in submerged settlements, ancient artifacts, and sea walls buried just offshore.

While the global mean sea level has been rising more than 7 cm in the last 25 years – forcing coastal settlements to build defenses and retreat to higher ground – the 21st century predicted rising rate of sea level along the Israeli coast will force the construction of coastal defenses, such as breakwaters and submerged breakwaters. However, engineered structures rarely solve all problems and regularly create new problems. As the sea level rises and human interference continues, the Israeli coast will experience more intense flooding, disappearing beaches, and intensifying coastal erosion.

A place that is already experiencing intense damage is one of Israel’s most well-known ancient sites: Caesarea. Named by Travel & Leisure as 2020’s best tourist spot in the Middle East, Caesarea, as described by Tourist Israel, is “a magnificent site, a national park where amazing ancient harbor ruins, beautiful beaches, and impressive modern residences sit side by side.”

Scientists in Israel, like University of Haifa’s Beverly Goodman-Tchernov, have endeavored to uncover the country’s past through underwater archaeology techniques and excavating sites, one of which is Caesarea.

Dr. Goodman-Tchernov’s research focuses on coastlines and how they have changed, along with reconstructing excavated sites that show evidence of ancient tsunamis. Over the years in the field, she’s witnessed intensifying winter storms destroying what she’s previously documented, which means racing against the clock to document historical sites before they are destroyed by the relentless tides.

When chatting with Dr. Goodman-Tchernov, who has studied the changing coastlines of Israel, she equated her understanding of coastlines to the old saying: “you never step in the same river twice.” This is because the beaches “are in constant flux,” but the overall trend Dr. Goodman-Tchernov has seen is “we’re losing sand and losing coast.”

As coastal cities prepare against the rising tide, defenses are built that remedy erosion from constant wave action, but only for a short while. Unfortunately, these structures, which were designed to preserve the coast, inadvertently trap sand around them and thereby exacerbating the rate at which other beaches are disappearing.

As the sea level rises and human interference continues, the Israeli coast will experience more intense flooding, disappearing beaches, and intensifying coastal erosion. Photo by Yaopey Yong on Unsplash

Where is the sand going?

Along with the disappearance of timeless artifacts, beaches are vanishing before our very eyes, as sand is impeded from its northward migration from the Nile delta. Artificial structures along Israel’s coast trap sand that would otherwise travel northward along the Mediterranean Sea, but the development of coastal cities has resulted in sand piling on the south of coastal construction sites.

What’s being done?

In 2015, artificial breakwaters were approved in the coastal cities of Netanya, Herzliya, and Ashkelon in an effort to mitigate the impact of winter storms on their coastal sandstone cliffs, and 2019 marked the year a submerged geotube – which is a fabric tube full of sand to aid in restoring the beach– was approved for installation off the north coast of Tel Aviv’s last non-protected beach. While these developments aim to lessen coastal erosion, they are met by local surfers and environmentalists with skepticism and contention as they counterintuitively encourage the loss of sand along other parts of the coast and create dangerous swimming conditions for unsuspecting beach-goers. 

The Israel Ministry of Foreign Affairs (IMFA) released a statement on the threat of coastal erosion for antiquity sites like Caesarea, Tel Ashkelon, and Apollonia. The statement described a plan funded by the prime minister’s office to create a series of coastal parks where sand will be channeled to beaches and protected from the relentless waves by building breakwaters with additional reinforcements.


Artificial breakwaters in the coastal cities of Netanya, Herzliya, and Ashkelon are supposed to mitigate the impact of winter storms on their coastal sandstone cliffs. Photo by Shai Pal on Unsplash

A global issue

Erosion threatens coastal communities worldwide, but human interference in an effort to remedy the problem appears to exacerbate sand loss and coastal erosion in adjacent unprotected sites. Relentless beating from ocean waves is a difficult opponent to battle, but some communities have found small successes in slowing the rising problem.

The Monterey Bay National Marine Sanctuary along the central California coast in the United States boasts a sweeping coastline and has been home to a destructive beach-front sand mining operation where the coast has eroded by an estimated 4 feet each year. Since mining began in 1906, sand has been removed from these shores at an alarming rate, and years of protesting and grass-roots movements have ordered all sand mining in the area to shut down by the end of 2020. This small win will drastically slow the rate at which nearby beaches have been eroding.

On the opposite coast of the United States, Florida’s Miami Beach is fighting a losing battle to keep its billion-dollar infrastructure above water by allocating $16 million to purchase 16,000 tons of sand to delay the inevitable rising tide. Federally funded “beach re-nourishment” projects at this scale are a routine event and will continue to occur as coastal erosion continues to threaten the citizens and tourists that visit Miami Beach.

The issue of thinning beaches and coastal erosion leads to an exposed coastline that is vulnerable to natural disasters that are increasing with intensity and severity due to a changing climate. Concerns over rising tides and erosion for coastal cities must be considered for the success of future communities.

The coastal city of Marina located near the center of Monterey Bay is doing just that by implementing a comprehensive strategy to level with the rising seas by minimizing nearshore development. By managing a controlled retreat from the encroaching tide rather than build expensive ocean-front homes, hotels, and restaurants and coastal barriers, this quaint, nature-centered city is growing and adapting to a future where a higher sea level is certain.

The Monterey Bay National Marine Sanctuary along the central California coast in the United States boasts a sweeping coastline and has been home to a destructive beach-front sand mining operation where the coast has eroded by an estimated 4 feet each year. Photo by Guillaume Merle on Unsplash

What does this mean for the future?

A future with a relentlessly rising ocean threatens the stability and safety of coastal communities. According to a report by the Intergovernmental Panel on Climate Change (IPCC), the global mean sea level (GMSL) will rise between 0.43 m and 0.84 m until 2100. Israel’s government is constructing artificial structures to protect the coast, but these measures impede the migration of sand northwards from the Nile Delta. Dr. Beverly Goodman-Tchernov has studied the changing coastline and has noticed “less sediment coming to our beaches.” The coming years will be for trial and error with necessary adaptation to infrastructure to accommodate the dynamic ocean forces, not least to ensure a future for ancient marvels like Caesarea.

This ZAVIT article was also published in NoCamels on 05/24/2020.


       







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