Latest news with #SaraFouad
Yahoo
12-03-2025
- Science
- Yahoo
In This Storied Egyptian City, Rising Seas are Causing Buildings to Crumble
As waters rise along the Egyptian coast, hundreds of buildings in the historic port city of Alexandria have collapsed. 'For centuries, Alexandria's structures stood as marvels of resilient engineering, enduring earthquakes, storm surges, tsunamis, and more,' said Sara Fouad, of the Technical University of Munich. 'But now, rising seas and intensifying storms — fueled by climate change — are undoing in decades what took millennia of human ingenuity to create.' Fouad is the lead author of a new study investigating why, over the past two decades, the number of buildings collapsing each year in Alexandria has risen tenfold. For the research, scientists compared present-day satellite imagery with decades-old maps to track the retreat of Alexandria's shoreline, inferring where rising seas had intruded into groundwater. Researchers also mapped which buildings had collapsed and studied soils for evidence of intrusion. Their research, published in Earth's Future, showed that buildings are collapsing from the bottom up as a rising water table weakens soil and erodes foundations. Authors called for building sand dunes and planting trees along the coast to block encroaching seawater, noting that more than 7,000 buildings are at risk. Since 2001, Alexandria has seen 290 buildings collapse. 'The true cost of this loss extends far beyond bricks and mortar. We are witnessing the gradual disappearance of historic coastal cities, with Alexandria sounding the alarm,' said study coauthor Essam Heggy, of the University of Southern California. 'What once seemed like distant climate risks are now a present reality.'
Yahoo
09-03-2025
- Science
- Yahoo
Ancient city crumbles as looming threat begins to wreak havoc: 'Undoing in decades what took millennia of human ingenuity to create'
The ancient Egyptian city of Alexandria is increasingly succumbing to rising sea levels and saltwater intrusion. As a result, researchers fear crucial historical information could be lost, and the impacts could be far-reaching. A team from the University of Southern California examined shoreline changes in Alexandria using a three-pronged approach, according to a news release published by EurekAlert. Using satellite imagery and historical maps from 1887, 1959, and 2001, the researchers created a detailed digital map of Alexandria's densely populated urban area. They also took samples to analyze whether the soil contained low levels of isotopes, which would indicate erosion. Alexandria soil radiation scientist Ibrahim H. Saleh, one of the study's co-authors, said that "buildings are collapsing from the bottom up, as seawater intrusion erodes foundations and weakens the soil." "For centuries, Alexandria's structures stood as marvels of resilient engineering, enduring earthquakes, storm surges, tsunamis, and more," added first author Sara Fouad, a landscape architect at the Technical University of Munich. "But now, rising seas and intensifying storms … are undoing in decades what took millennia of human ingenuity to create." Alexandria is among a growing number of coastal cities in peril. For instance, in Papua New Guinea, rising sea levels have displaced tens of thousands of people. As the researchers pointed out in EurekAlert, rising seas are impacting cities in California, where saltwater intrusion has degraded water supplies, contributed to a higher cost of living, and weakened infrastructure. "Our study demonstrates that coastal buildings are at risk of collapsing even without directly encroaching on the seawater as widely believed," said corresponding author Essam Heggy, a water scientist at the USC Viterbi School of Engineering. Situated on the Mediterranean, Alexandria was also a hub of learning, science, and cultural exchange. If things continue on the same trajectory, the knowledge it holds could be diminished or lost because of the effects of rising global temperatures, driven higher at an unnatural rate by human activities, particularly the burning of dirty fuels. "Historic cities like Alexandria, which represent the cradle of cultural exchange, innovation, and history, are crucial for safeguarding our shared human heritage," Heggy said in the news release. "As climate change accelerates sea level rise and coastal erosion, protecting them isn't just about saving buildings; it's about preserving who we are." Do you think we still have a lot to learn from ancient cultures? Definitely Only on certain topics I'm not sure No — not really Click your choice to see results and speak your mind. The USC team is advocating for nature-based solutions to mitigate the situation in Alexandria, per the release. Potential actions include building sand dunes and cultivating vegetation barriers — techniques already proven to boost climate resilience in coastal communities. Furthermore, as explained by study co-author Steffen Nijhuis, a landscape-based urbanist from the Netherlands' Delft University of Technology, this approach is cost-effective. In the long term, bringing the planet's temperatures into balance can help slow down the melting of ice sheets — a key factor contributing to rising sea levels and subsequent saltwater intrusion. As countries around the world increase their mix of nonpolluting, renewable energy, you can support these efforts by upgrading to energy-efficient appliances and unplugging electronic devices when they aren't in use. Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
The Hill
21-02-2025
- Science
- The Hill
Climate change is coming for coastlines, from ancient cities to modern California: study
Climate change-induced seawater intrusions are hastening the collapse of buildings in the ancient Egyptian port city of Alexandria — posing threats similar to those challenging coastal California, a new study has found. While such breakdowns were once a rare occurrence in Alexandria, these events have surged from approximately one to about 40 per year over the past decades, according to the study, published on Thursday in Earth's Future. 'For centuries, Alexandria's structures stood as marvels of resilient engineering, enduring earthquakes, storm surges, tsunamis and more,' lead author Sara Fouad, a landscape architect at the Technical University of Munich, said in a statement. 'But now, rising seas and intensifying storms — fueled by climate change — are undoing in decades what took millennia of human ingenuity to create,' Fouad added. The researchers used geographic information system technology to create digital maps focusing on six districts across the city's historic and densely populated urban area. Details included in the maps pertain to each structure's composition, size and foundation depth — information collected from site visits and reports from 2001 through 2021. The researchers then combined satellite imagery with historical maps from 1887, 1959 and 2001 to measure shoreline movement and to understand how the 50-mile coastline shifted inland in recent decades. After calculating the rate of shoreline retreat over the past century, the scientists determined that the diminishing coastline was raising groundwater levels — and hurling that water into the foundations of seaside structures. The researchers also analyzed what they described as chemical 'fingerprints' in soil samples, which included specific isotopes that were indicative of soil strength and stability versus erosion. 'Our isotope analysis revealed that buildings are collapsing from the bottom up, as seawater intrusion erodes foundations and weakens the soil,' co-author Ibrahim Saleh, a soil radiation scientist at Alexandria University, said in a statement. 'It isn't the buildings themselves, but the ground underneath them that's being affected.' These findings also demonstrate that coastal structures are under threat of collapse 'even without directly encroaching on the seawater,' added corresponding author Essam Heggy, a water scientist at the University of Southern California's Viterbi School of Engineering. Like Alexandria, the researchers warned, California's coastal cities are facing increased danger from saltwater intrusion, which could weaken infrastructure, degrade water supplies and drive up the cost of living there as well. Recent studies have shown that parts of the Golden State, including the San Francisco Bay Area, the Central Valley and coastal Southern California, are sinking, the authors noted. And what might appear to be minor elevation changes could cause a tremendous rise in the flood and seawater intrusion risks, according to the scientists. 'Our study challenges the common misconception that we'll only need to worry when sea levels rise by a meter,' Heggy said in a statement. 'However, what we're showing here is that coastlines globally, especially Mediterranean coastlines similar to California's, are already changing and causing building collapses at an unprecedented rate,' he added. In addition to sounding the alarm on these new coastal erosion threats, Heggy and his colleagues also proposed a nature-based solution in their study. They raised the idea of creating sand dunes and vegetation barriers along shorelines to hinder seawater encroachment and thereby prevent groundwater from reaching building foundations. Such an approach, they argued, could be applied to densely-populated coastal cities around the world, in a sustainable and cost-effective manner. Without taking such action, coastal residents could be left with a loss that 'extends far beyond bricks and mortar,' Heggy noted. 'We are witnessing the gradual disappearance of historic coastal cities, with Alexandria sounding the alarm,' he added. 'What once seemed like distant climate risks are now a present reality.'
