Barrier islands protect coasts from storms, but are vulnerable too

first_img Please enter your name here Free webinar for job seekers on best interview answers, hosted by Goodwill June 11 Share on Facebook Tweet on Twitter Hurricane Season 2018By Anna Linhoss, Assistant Professor of Agricultural and Biological Engineering, Mississippi State University and first published on theconversation.com.When hurricanes like Florence make landfall, the first things they hit often are barrier islands – thin ribbons of sand that line the U.S. Atlantic and Gulf coasts. It’s hard to imagine how these narrow strips can withstand such forces, but in fact, many of them have buffered our shores for centuries.Barrier islands protect about 10 percent of coastlines worldwide. When hurricanes and storms make landfall, these strands absorb much of their force, reducing wave energy and protecting inland areas.They also provide a sheltered environment that enables estuaries and marshes to form behind them. These zones serve many valuable ecological functions, such as reducing coastal erosion, purifying water and providing habitat for fish and birds.Many barrier islands have been developed into popular tourist destinations, including North Carolina’s Outer Banks and South Carolina’s Hilton Head and Kiawah. Islands that have been preserved in their natural state can move with storms, shifting their shapes over time. But many human activities interfere with these natural movements, making the islands more vulnerable.Ocean City, Maryland is built on Fenwick Island, an Atlantic barrier island. USACEIslands on the moveBarrier islands are made of sandy, erodible soil and subject to high-energy wave action. They are dynamic systems that constantly form and reform. But this doesn’t necessarily mean the islands are disappearing. Rather, they migrate naturally, building up sand in some areas and eroding in other areas.New islands can form out in the ocean, either because local sea level drops or tectonics or sediment deposition raises the ocean floor. Or they may shift laterally along the shore as currents carry sediments from one end of the island toward the other. On the East Coast, barrier islands usually move from north to south because longshore currents transport sand in the same direction.How longshore drift moves sediment along a beach. 1=beach. 2=sea 3=longshore current direction 4=incoming waves 5=swash 6=backwash USGSAnd over time many barrier islands move landward, toward the shore. This typically happens because local sea levels rise, so waves wash over the islands during storms, moving sand from the ocean side to the inland side.Building on shifting sandsBuilding hard infrastructure such as homes, roads and hotels on barrier islands interrupts their lateral migration. Needless to say, beach communities want their dunes to stay in place, so the response often is to build control structures, such as seawalls and jetties.This protects buildings and roads, but it also disrupts natural sand transportation. Blocking erosion up-current means that no sediments are transported down-current, leaving those areas starved of sediment and vulnerable to erosion.Many sandy tourist beach towns along the East Coast also turn to beach nourishment – pumping tons of sand from offshore – to replace sand lost through erosion. This does not interrupt natural sand transportation, but it is a very expensive and temporary fix.For example, since the 1940s Florida has spent over US$1.3 billion on beach nourishment projects, and North Carolina has spent more than $700 million. This added sand will eventually wash away, quite possibly during Hurricane Florence or the next hurricane to hit the coast, and have to be replaced.What kind of protection?In some cases, however, leaving barrier islands to do their own natural thing can cause problems for people. Some cities and towns, such as Miami and Biloxi, are located behind barrier islands and rely on them as a first line of defense against storms.And many communities depend on natural resources provided by the estuaries and wetlands behind barrier islands. For example, Pamlico Sound – the protected waters behind North Carolina’s Outer Banks – is a rich habitat for blue crabs and popular sport fish such as red drum.Landsat image of North Carolina’s Outer Banks enclosing Pamlico Sound. NASAUnmanaged, some of these islands may not move the way we want them to. For example, a storm breach on a barrier island that protects a city would make that city more vulnerable.Here in Mississippi, a string of uninhabited barrier islandsoff our coast separates Mississippi Sound from the Gulf of Mexico. Behind the islands is a productive estuary, important wetlands and cities such as Biloxi and Gulfport. Because the Mississippi River has been dredged and enclosed between levees to keep it from spilling over its banks, this area does not receive the sediment loads that the river once deposited in this part of the Gulf. As a result, the islands are eroding and disappearing.To slow this process, state and federal agencies are artificially nourishing the islands to keep them in place and preserve the cities, livelihoods and ecological habitats behind them. This project will fill a major breach cut in one island by Hurricane Camille in 1969, making the island a more effective storm buffer for the state’s coast.When to retreat?Geologically, barrier islands are not designed to stay in one place. But development on them is intended to last, although critics argue that climate change and sea level rise will inevitably force a retreat from the shore.Reconciling humans’ love of the ocean with the hard realities of earth science is not easy. People will always be drawn to the coast, and prohibiting development is politically impractical. However, there are some ways to help conserve barrier islands while maintaining areas for tourism activities.First, federal, state and local laws can reduce incentives to build on barrier islands by putting the burden of rebuilding after storms on owners, not on the government. Many critics argue that the National Flood Insurance Program has encouraged homeowners to rebuild on barrier islands and other coastal locations, even after suffering repeated losses in many storms.Late-night host John Oliver critiques federal flood insurance.Second, construction on barrier islands should leave dunes and vegetation undisturbed. This helps to keep their sand transportation systems intact. When roads and homes directly adjacent to beaches are damaged by storms, owners should be required to move back from the shoreline in order to provide a natural buffer between any new construction and the coastline.Third, designating more conservation areas on barrier islands will maintain some of the natural sediment transportation and barrier island migration processes. And these conservation areas are popular nature-based tourism attractions. Protected barrier islands such as Assateague, Padre and the Cape Cod National Seashore are popular destinations in the U.S. national park system.Finally, development on barrier islands should be done with change in mind and a preference for temporary or movable infrastructure. The islands themselves are surprisingly adaptable, but whatever is built in these dynamic settings is likely sooner or later to be washed away. The Anatomy of Fear Support conservation and fish with NEW Florida specialty license plate TAGSHurricane Season 2018theconversation.com Previous articleCookies and Milk with a Cop this morningNext articleNew cars lose $3,000 annually from this single expense Denise Connell RELATED ARTICLESMORE FROM AUTHOR Please enter your comment! You have entered an incorrect email address! Please enter your email address here LEAVE A REPLY Cancel reply Save my name, email, and website in this browser for the next time I comment.last_img read more

Gunners to honour Bergkamp in bronze

first_imgArsenal will honour former striker Dennis Bergkamp with a statue outside their Emirates Stadium home, the club confirmed on Wednesday evening. Holland international Bergkamp scored 120 goals for the Gunners, before retiring in 2006, helping spearhead Arsene Wenger’s team to unprecedented domestic success as part of the Invincibles’ unbeaten Premier League season of 2003-04. Bergkamp said: “First of all, I am honoured that this is going to happen. It makes me very proud. Everyone knows that I love Arsenal and that I had a fantastic time at the club. For me and my family it was an important period in our lives. Next to that the people were great, the team was amazing and we had a lot of success over the years. “I will do everything I can to be there when it will be unveiled. It will definitely be a special moment for me which I don’t want to miss.” Arsenal are to confirm at a later date the timings of the statue’s placement. Chief executive Ivan Gazidis said: “It will be a fitting tribute to Dennis’ huge contribution to the club that a statue will be on display outside Emirates Stadium in the near future. “Dennis’ quality and style of play will never be forgotten. He is a true legend of Arsenal and it’s great to think that so many Arsenal supporters and visitors to Emirates Stadium will be able to enjoy this tribute to such a great player for years to come.” Gazidis suggested tonight’s announcement had been brought forward in light of pictures surfacing online, which depicted the striker in a pose as he controlled the ball in mid-air against Newcastle in 2003. Bronze statues of former manager Herbert Chapman, double-winning captain Tony Adams and record goalscorer Thierry Henry are already in place around the ground at Ashburton Grove, where Arsenal moved from Highbury in 2006. Images of a cast for Bergkamp were leaked online, and the club issued a statement on their website confirming the plans. center_img Press Associationlast_img read more

Miami Beach Convention Center to convert into field hospital

first_imgThe Miami Beach Convention Center will be turned into a field hospital during the coronavirus pandemic. It is not clear whether it will house coronavirus patients or serve as an overflow hospital.The U.S. Army Corps of Engineers will transform the newly renovated facility into a hospital by April 27.The Miami Herald reports the decision to install 450 preliminary beds in the center was made in order to prepare the city for the worst case scenario.Miami Beach Mayor Dan Gelber says the field hospital will hopefully sit vacant until it’s dismantled.last_img

Shoaib Akhtar advocates adding a ‘G’ before Rohit Sharma’s name to represent the word…

first_imgAdvertisement 1j65NBA Finals | Brooklyn VsyawWingsuit rodeo📽Sindre E0ad( IG: @_aubreyfisher @imraino ) cmWould you ever consider trying this?😱7dz6Can your students do this? 🌚u2qjRoller skating! Powered by Firework Before India’s first test against South Africa, a big section of supporters doubted Rohit Sharma’s position in the test squad. A magnificent 176 at Vishakapatnam has shut them up and reminded everybody that modern Indian Cricket is synonymous to Rohit Sharma.Advertisement This fact was even acknowledged by Pakistan legend Shoaib Akhtar in his facebook video.Advertisement “I had asked Rohit to add a G, for Great before his name (Great Rohit Sharma) and play in the manner going in with the mindset that he is the best batsman in India,” Akhtar said in the video, refering to 2013.The Rawalpindi express also added that – Rohit is also turning out to be a modern-day great like Virat Kohli and Steven Smith. The former Pakistan pacer also said that in future when India face-off against England in a five-match Test series, Rohit could amass 1000 runs in the rubber and will surpass Smith’s run tally of 774 runs in the recently concluded Ashes series.Advertisement Advertisementlast_img read more