Friday, April 06, 2012

'Surging Seas': N.J. in top 5 states most threatened by rising sea levels, study says

From: newjerseynewsroom  By: Angeloa Daidone

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The waters are rising, and New Jersey coastal communities are right in their course.

A study by a Princeton-based research group lists the Garden State as one of the top five states most threatened by rising sea levels which are increasing the likelihood of more catastrophic tidal flooding during storms, the Press of Atlantic City reported.

The study, titled "Surging Seas," said the seas are predicted to rise about 15 inches by 2050 in Atlantic City and Cape May. As a result, storms that used to be considered once-in-a-lifetime events will happen more frequently, the study said. Cape May and Atlantic City may see levels rise by half a foot by 2030, the study stated.

Researchers based their findings on current census population, existing topographical maps and digital map analysis showing inundation zones by each foot of water above the current average high tide line.

Of the 22 coastal states, Florida and Louisiana have the largest number of people at risk of being affected by sea level rise. New Jersey ranked fifth. Recent storms have seen an increase in severe flooding, impacting residential communities, major roads and businesses.

The combination of flooding from storm surges on top of an increased base sea level would put more than 200,000 people and 160,000 homes at risk in New Jersey, the study stated.

Storm surges from northeasters differ from hurricane and tropical storm surges, particularly because there is a limit to how high the water can reach, said a researcher at Stevens Institute of Technology in Hoboken. A northeaster storm surge only will reach about six feet, but will last much longer. A hurricane can bring a more localized high surge, but the coastal flooding will last only a short time, the report stated.

What's at stake in the long run is the main concern of the findings, experts said. Ratables and tourism dollars in vacation communities, residential property values, and beaches and natural coastlines will likely take a big hit if the issue is not addressed on a wide scale, experts said.

Thursday, April 05, 2012

As climate changes, Louisiana seeks to lift a highway

From: The Washington Post

Tim Osborn/National Oceanic and Atmospheric Association - Rising sea levels near Leeville, La., during the past 100 years have left this 1905 cemetery entirely underwater.

GOLDEN MEADOW, La.— Here on the side of Louisiana’s Highway 1, next to Raymond’s Bait Shop, a spindly pole with Global Positioning System equipment and a cellphone stuck on top charts the water’s gradual encroachment on dry land.

In 1991 this stretch of road through the marshlands of southern Louisiana was 3.9 feet above sea level, but the instrument — which measures the ground’s position in relation to sea level — shows the land has lost more than a foot against the sea. It sank two inches in the past 16 months alone.

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Rising seas will make the road to Port Fourchon, La., largely unusable by the end of the century.

Click Here to View Full Graphic Story

Rising seas will make the road to Port Fourchon, La., largely unusable by the end of the century.

Video

Windell Curole, general manager of the South Lafourche Levee District, and Henri Boulet, executive director of the LA 1 Coalition, discuss the challenge sea level rise poses for Louisiana's Highway 1.

Windell Curole, general manager of the South Lafourche Levee District, and Henri Boulet, executive director of the LA 1 Coalition, discuss the challenge sea level rise poses for Louisiana's Highway 1.

That’s a problem because Highway 1, unprotected by levees, connects critical oil and gas resources in booming Port Fourchon to the rest of the nation.

Ten miles of the highway is now standing 22 feet above sea level on cement piles. But another seven miles is not, and if less than half a mile of this highway succumbs to the 14-foot storm surges expected in the future, the highway will need to be shut down, cutting off the port.

Local residents and business leaders are demanding that the federal government help pay to rebuild and elevate the remaining section of Highway 1, adding two miles to span the levees. Federal officials have provided scientific and technical expertise but will not contribute funding unless the state pledges to complete the road.

Louisiana says it doesn’t have the money.

The dilemma facing this important lowland road is one shared by communities across the country as climate change begins to transform the nation’s landscape. By 2030, many areas in the United States are likely to see storm surges combining with rising sea levels to bring waters at least four feet above the local high-tide line, according to a report released last Wednesday by Climate Central, a nonprofit research group. Nearly 2.6 million homes are on land that would be inundated.

The Obama administration is trying to plan for a country altered by shifts in precipitation, higher oceans and more intense periods of heat. It is rethinking infrastructure projects and creating a new plan for how to manage plants and wildlife in the face of global warming. Every agency is required to come up with a plan by June for how to adapt to climate change.

“It’s about how do we incorporate planning for a future that may look very different from the way the world looks today,” said Nancy Sutley, chair of the White House Council on Environmental Quality, who is spearheading the administration’s federal adaptation strategy.

Researchers at the National Oceanic and Atmospheric Administration, who started measuring tides in Louisiana in the mid-1800s, have analyzed the numbers for Highway 1, and they do not bode well. At today’s rate of sea-level rise — 9.24 millimeters a year — the road would be under water roughly 22 days of the year by 2030.

Windell Curole didn’t need NOAA’s number-crunching to tell him what’s coming. The 60-year-old general manager of the South Lafourche Levee District said he couldn’t see open water from this road when he was growing up. Now, it is in plain sight, just yards away.

Tuesday, April 03, 2012

Rising Sea Levels Could Boost Storm Surges

Source: redOrbit

Rising Sea Levels Could Boost Storm Surges

Sea level rise due to global warming has already doubled the annual risk of coastal flooding of historic proportions across widespread areas of the United States, according to a new report from Climate Central. By 2030, many locations are likely to see storm surges combining with sea level rise to raise waters at least 4 feet above the local high-tide line. Nearly 5 million U.S. residents live in 2.6 million homes on land below this level. More than 6 million people live on land below 5 feet; by 2050, the study projects that widespread areas will experience coastal floods exceeding this higher level.

Titled “Surging Seas,” the report is the first to analyze how sea level rise caused by global warming is compounding the risk from storm surges throughout the coastal contiguous U.S. It is also first to generate local and national estimates of the land, housing and population in vulnerable low-lying areas, and associate this information with flood risk timelines. The Surging Seas website includes a searchable, interactive online map that zooms down to neighborhood level, and shows risk zones and statistics for 3,000 coastal towns, cities, counties and states affected up to 10 feet above the high tide line.

In 285 municipalities, more than half the population lives below the 4-foot mark. One hundred and six of these places are in Florida, 65 are in Louisiana, and ten or more are in New York (13), New Jersey (22), Maryland (14), Virginia (10) and North Carolina (22). In 676 towns and cities spread across every coastal state in the lower 48 except Maine and Pennsylvania, more than 10% of the population lives below the 4-foot mark.

Tidal gauge records show that the sea has already risen 8 inches globally during the last century, and projections point to a steep acceleration. “Sea level rise is not some distant problem that we can just let our children deal with. The risks are imminent and serious,” said report lead author Dr. Ben Strauss of Climate Central. “Just a small amount of sea level rise, including what we may well see within the next 20 years, can turn yesterday’s manageable flood into tomorrow’s potential disaster. Global warming is already making coastal floods more common and damaging.”

In addition to the Surging Seas report and website, Climate Central is releasing fact sheets laying out the risks for each coastal state. Staff scientists (Ben Strauss, Claudia Tebaldi, Remik Ziemlinski) have also authored two peer-reviewed studies being published March 15th in the scientific journal Environmental Research Letters, with co-authors at the University of Arizona (Jeremy Weiss, Jonathan Overpeck) and the National Oceanic and Atmospheric Administration (Chris Zervas).  In addition to hosting the map tool, the national report, state fact sheets, and the peer-reviewed papers, the website, SurgingSeas.org, includes downloadable data for all the cities, counties and states studied; embeddable widgets; republishable graphics; and links to dozens of local, state and national planning documents for coping with rising seas.

The website also shows how the threat from climate change-driven sea level rise and storm surge is expected to increase over time at 55 tidal gauges around the U.S. and near most major coastal cities. At the majority of these gauges, floods high enough to formerly be called worse than once-a-century events have more than doubled in likelihood.

Land, housing and population vulnerability estimates are based on 2010 Census data and on land elevations relative to potential water levels, and do not take into account potential protections.  However, properties behind walls or levees may suffer enhanced damage when defenses are overtopped, or during rainstorms, because the same structures that normally keep waters out can keep floodwaters in once they arrive.

“Escalating floods from sea level rise will affect millions of people, and threaten countless billions of dollars of damage to buildings and infrastructure,” Strauss said. “To preserve our coastal towns, cities and treasures, the nation needs to confront greenhouse gas pollution today, while also preparing to address sea level rise that can no longer be avoided.

Sunday, April 01, 2012

Flood Outlook 2012: Hoping for the Best, Preparing for the Worst

From: USGS

It’s difficult to forget the epic flooding along the Mississippi, Missouri, and many other rivers throughout 2011. Of course, the memory of these floods is especially vivid for those living in cities like Minot, N.D., where 12,000 people had to evacuate their homes and where record flooding caused an estimated $1 billion in damage; or in Cairo, Ill., where officials had to make complex decisions about whether to divert flood waters onto farmland in order to save the city.

Looking east at Burdick Expressway as the Souris River rises in Minot, North Dakota. Photo taken by USGS personnel during a FEMA Flood Inundation Mapping Project.

Throughout the last century in the United States, on average, floods have caused more lives lost and more economic damage than any other natural hazard. According to forecasts, severe flooding in 2012 will likely be far less widespread than last year. However, scientists cannot predict weather and water patterns with 100 percent accuracy, and there is always the potential for severe flooding somewhere in the country.

When it comes to flooding, preparation is key for saving lives and protecting property. USGS scientists and hydrologic technicians are specially trained and standing by. As soon as water starts to rise, they are measuring water levels, river velocities, and high water marks. All of this information is crucial for National Weather Service flood forecasts, for decisions by the U.S. Army Corps of Engineers to operate spillways and levees, and for the planning of Federal, State, and local emergency managers, first responders, and many other groups.

In preparation for flood events, the USGS continues to invest in and update equipment like the acoustic Doppler current profiler, which measures water velocity, as well as rapidly deployable streamgages, which measure river heights in areas that do not have a permanent gage or where a gage has been damaged by fast-moving water.

Perhaps most importantly, the USGS is constantly refining, innovating, and updating its ability to deliver river information to emergency managers, first responders, and other Federal agencies before, during, and after a flood. The USGS offers an increasing number of resources to help these organizations, as well as you and your family, better prepare for flood hazards.

Flood Inundation Mapping

When the water starts to rise, how do you know if you’re going to get wet?

Right now, if you want to see areas where river levels are higher than normal, you can go to USGS WaterWatch and view a map of the thousands of real-time streamgages that constantly monitor the Nation’s rivers and streams. But how do you put that number in context? If the current stage is forecasted to go above flood stage, does that mean water will be barely spilling over the banks? Or does it mean that your house might be underwater? At what stage is the river going to spill over onto a roadway and affect traffic? Are you and your family in danger?

River stage measurements can be confusing, and they are not always a great indicator of the actual scope and impacts of the flooding. To reduce this ambiguity, the USGS and the National Weather Service are working together to create visual products, called flood inundation map libraries, that show you estimates of where the water will be — what roads, yards, and buildings will be affected — when a river or stream reaches a certain stage.

For example, in Findlay, Ohio, the flood inundation map shows that when the stream stage is around 11 feet, only the roads closest to the river are underwater, but the rest of the town is out of danger. However, when you use the tool to map out a flood stage of 18 feet, streets as far as 15 blocks away from the river’s banks are underwater, as are a few parks, a cemetery, and almost the entire Findlay Country Club.

A powerful new tool for flood response and mitigation are digital geospatial flood-inundation maps that show flood water extent and depth on the land surface. Because floods are the leading cause of natural-disaster losses, the U.S. Geological Survey (USGS) is actively involved in the development of flood inundation mapping across the Nation pursuant to its major science strategy goal of reducing the vulnerability of the people and areas most at risk from natural hazards. Flood inundation maps have been created for cities on the map indicated by a black triangle (Iowa City, IA, Marshall, MI, Ottawa, OH, Findlay, OH, Peach Creek, near Atlanta, GA, Albany, GA, Trenton, NJ St. John River, near Fort Kent, ME, and Scituate, MA).

In Iowa City, Iowa, the flood inundation map shows that when the stream stage is at 17 feet, the river is barely out of the channel, and most of the town is out of danger. But when you map out a flood stage of 25 feet, parks and local areas designed to hold floodwaters are submerged. At 30 feet, several neighborhoods and much of the University of Iowa are flooded. On this map, you can click anywhere in the flooded area to see the estimated water depth for any location at any stage. Damage estimation models, which are based on FEMA’s Hazus tool, are also available for each flood stage on the map. All of these features allow emergency managers to see what areas and how many people need to be evacuated, and to estimate the cost of potential flood damages.

This new tool is especially useful to emergency managers responsible for keeping people safe on the roads. In fact, over half of all flood-related deaths are the result of people driving their cars onto submerged roadways. These new, interactive flood maps allow emergency managers to see what roads will be submerged at a forecasted flood level, so that the roads can be closed long before waters start to rise.

Flood inundation maps have already been produced for nine areas in the United States. The USGS plans to produce over 40 more of these maps within the next year, including for Terra Haute, Ind., Sweetwater Creek, Ga., and Hattiesburg, Miss. The USGS hopes to eventually have flood inundation map libraries available for many other areas across the country.

You can see what areas have already been mapped by using the tool.

WaterAlert

Smartphones let you know when the river is rising

If you’re on the USGS site and reading this, chances are you probably have a favorite outdoor spot, a favorite river, and perhaps a favorite streamgage that you check on a regular basis. Did you know that you can get automatic notifications from that streamgage sent straight to you as an email or text message? The USGS provides a service called WaterAlert that can text or email you when water levels at a streamgage of interest exceed certain thresholds.

This means that you can keep tabs on a river without having to repeatedly check the USGS website. And if waters start to suddenly rise, you will be alerted, allowing you to put necessary precautions in place to keep yourself, your family, and your property safe.

USGS scientists take streamflow and water quality measurements downstream of the Bonnet Carre Spillway near Norco, La. The Army Corps of Engineers uses USGS streamflow data to help them manage flood control structures.

Sign up for WaterAlert by selecting a State, checking the “surface water” box, and clicking on your streamgage of choice. You can also subscribe to WaterAlert from the flood inundation interactive map. If you live in a community covered by a flood inundation library, use the flood inundation map to discover what flood stage puts you at risk, then click the link in the “Services and Data tab” to sign up to receive a text or email when the water approaches, reaches, or exceeds that stage!

Links:

Flood Inundation Interactive Mapper: http://wim.usgs.gov/FIMI/FloodInundationMapper.html

Additional information about Flood Inundation Mapping: http://water.usgs.gov/osw/flood_inundation/

WaterAlert: http://water.usgs.gov/wateralert/

Main USGS Flood Site: http://water.usgs.gov/floods

News Release: Smart Phones Know When Rivers Rise…with USGS WaterAlert: http://www.usgs.gov/newsroom/article.asp?ID=2919

News Release: Instant Information about Water Conditions: Ask the River to Text You a WaterAlert: http://www.usgs.gov/newsroom/article.asp?ID=2464