USGS Reports to Help Community Planners (USA)

The probability of hurricane-induced coastal change on sandy beaches from Florida to New York has been assessed for the first time in two U.S. Geological Survey studies released yesterday.

The two reports, one assessing the coastline from Florida to North Carolina, the other from Virginia to New York, can function as part of a “virtual toolkit” for U.S. Atlantic coast community planners and emergency managers as they make decisions on how to best address coastline vulnerabilities.

The reports show that even during the weakest hurricane, a category 1 with winds between 74 and 95 miles per hour, 89 percent of the dune-backed beaches from Florida to New York coast are very likely to experience dune erosion during a direct landfall. But scientists involved say the strength of the studies is in their ability to predict coastal change in specific areas.

The online mapping tool, based on a USGS state-of-the-art model, will allow community planners and emergency managers to focus on a specific storm category and see the predicted coastal change in their area. The information may help them with decisions ranging from changes to building codes and locations for new construction, to determining the best evacuation routes for future storms.

The USGS has been working on identifying storm-driven coastal change hazards for more than a decade,” said Hilary Stockdon, a USGS research oceanographer and co-author of the studies. “The data collected and modeling capabilities developed during that period are what’s enabled us to complete these regional assessments of predicted coastal change, providing key information to decision makers working to build more resilient communities and take actions to protect lives and property before storms hit.”

USGS Reports to Help Community Planners.

For the entire study area, the modeling also shows that during a category 1 hurricane, storm waves are expected to increase water levels at the shoreline by approximately 150 percent above storm surge levels. This means in a category 1 storm that waves alone would raise water levels at the shoreline by approximately 2.6 to 3.3 meters (8.5 to 10.8 feet), depending on the region. Results show that waves play a significant role in elevating water levels during lower category storms, while storm surge is the major contributor to high water levels in stronger storms.

In an assessment of dune height from Florida to New York, the researchers found the southeast coasts, because of their lower dune elevations, more likely to experience overwash, or the landward movement of beach sand, than coastlines farther north. Dune heights from Delaware to New York are 1.4 meters (4.6 feet) higher, on average, than the dunes from Maryland south to Florida. The South Carolina coast, where average dune elevations are only 2.9 meters (9.5 feet), is the most vulnerable to overwash of the beaches studied. Ninety-six percent of coastal locations in the state are likely to overwash if a category 1 hurricane makes landfall there.

Prior to Hurricane Sandy, dunes on New York’s south shore were among the highest on the Atlantic coast, and as such during a category 1 storm only 9 percent of coastal areas were likely to overwash. Still, these high dunes were vulnerable to extreme erosion during a category 1 hurricane, with 76 percent of the dunes very likely to be experience erosion. This was observed during Hurricane Sandy, which made landfall as an extra-tropical cyclone but pounded the beach with hurricane waves and surge. The protective sand dunes along barrier islands in New Jersey and New York were completely eroded in places, increasing vulnerability to more extreme erosion during future storms.

But vulnerability doesn’t just come down to dune height; scientists credit the continuity of the dunes as being one of the key reasons coastal vulnerabilities vary greatly along the coast.

“Large areas of the South Carolina coast are very likely to erode during hurricanes due to long, continuous stretches of low dunes. In other areas, such as Delaware and New York, the mix of high and low dune elevations creates a more complex picture of vulnerabilities where relatively safe areas are adjacent to areas that are likely to be inundated,” said Stockdon.

“Inundation” is a process by which an entire beach system is submerged and, in extreme cases, can result in island breaching. Only 9 percent of the entire study region is very likely to be inundated in a category 1 storm, although the percent is significantly higher in some regions. If a category 1 storm makes landfall on the South Carolina coast, for example, 34 percent of the beaches and dunes there are very likely to be inundated.

Beaches serve as a natural buffer between the ocean and inland communities, ecosystems, and natural resources. However, these dynamic environments move and change in response to winds, waves, and currents. During extreme storms, changes to beaches can be large, and the results are sometimes catastrophic. Lives may be lost, communities destroyed, and millions of dollars spent on rebuilding.

These reports and the mapping tool can serve as an important resource for coastal planners and emergency managers as they work to protect their communities from future storms.

Press Release, July 2, 2013

Share this article

Follow Dredging Today

One thought on “USGS Reports to Help Community Planners (USA)”

  1. Pingback: Homepage

Comments are closed.

Events>

<< Feb 2017 >>
MTWTFSS
30 31 1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 1 2 3 4 5

National Coastal Restoration Conference – Christchurch

The first three days will include speakers, seminars and local field-trips around the Christchurch urban beaches and the local North Canterbury coast…

read more >

(ISP-IDFC) International Combined Conference on INTEGRATION OF SEA PORTS & INNOVATIONS IN DREDGING & FUTURE CHALLENGES

The combined conference will focus towards enhancing the ports capabilities by doing the integration of our major and minor ports across…

read more >

Africa Ports Expansion 2017

Join senior officials from Kenya Ports Authority, Egypt’s Port Said Port Authority, Tanzania Ports Authority, Ghana Ports and Harbours Authority, Mauritius Ports Authority, Nigeria Ports Authority and more to gain insights into their port development plans and identify opportunities for your business.

More Info http://bit.ly/2jHFlmM

read more >

Coast & Marine Structures 2017

Join the 9th Annual Coasts and Marine Structures 2017 conference

Discover Best Practise Strategies for Design, Planning, Construction and Asset Management

To remain competitive, Australian port operators must plan, design, manage and maintain their assets more creatively and proactively to meet future demands and drive profitability.

With this in mind, our Coast and Marine Structures Summit 2017 will focus on key considerations relevant to ensuring your existing assets are maximised and prepared to accommodate bigger vessels.

Hear from 20+ global experts including Maritime/Coastal Engineers, Contractors, Port Authorities and more, including GHD (USA), Indonesian Port Corporation (Asia), G-Group Consulting (New Zealand), Ausenco (Australia), Port Authority NSW (Australia), to name a few.

By attending this 2-day conference, you’ll learn about:

Innovative planning and design of ports to create efficiencies that drive profit
Best practice asset management strategies and new PIANC design principles for bulk terminals
Proactive asset management and maintenance to improve durability and maximise and extend asset lifecycles
Alternative material and protection techniques trialled and tested in the US and Europe
Strategies to shift organisational culture and mindset from asset management to asset maintenance
How you can leverage technology to increase the efficiency of your marine structures
Case studies on retrofitting, expanding and upgrading your ports in cost-effective ways
To learn more or book a ticket, contact us now!

W: http://www.marinestructures.com.au/ 

P: +61 2 9229 1000

E: enquire@iqpc.com.au

Read More

read more >

Jobs>

Design & Proposal Engineer Dredging

As Design & Proposal Engineer you translate customer requirements into the design of a vessel in close cooperation with...

apply

Dredge Masters, Engineers and Superintendent\\\\\\\'s Urgently Required!

Flagship Management is working with a number of leading international marine and dredging organizations and require the following candidates for a range of global projects...

apply

Network Support Engineer

As Network Support Engineer you will be responsible for the installation / configuration, operation and maintenance of the infrastructural....

apply