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Posts Tagged ‘Coastal Conservancy’

msnbc.com, January 27, 2010

Lots has been said about warming temperatures and rising sea levels, but a new study puts the spotlight on a more imminent threat to coastal communities: extreme waves that are growing taller in some parts of the world.

Data from buoys off the Pacific Northwest coast found that since the mid-1970s the height of the biggest waves has increased on average by nearly four inches a year. That’s about 10 feet over that period.

“The waves are getting larger,” said lead author Peter Ruggiero, an assistant geosciences professor at Oregon State University.

And that, he said, means “the rates of erosion and frequency of coastal flooding have increased over the last couple of decades and will almost certainly increase in the future.”

In the study published in the journal Coastal Engineering, Ruggiero and his colleagues report that the reasons are not completely certain.

“Possible causes might be changes in storm tracks, higher winds, more intense winter storms, or other factors,” Ruggiero said. “These probably are related to global warming, but could also be involved with periodic climate fluctuations such as the Pacific Decadal Oscillation, and our wave records are sufficiently short that we can’t be certain yet.”

The team also looked at how high a “100-year event” might be, given that planners use those scenarios in approving development projects. Using the new data set, the researchers  estimated that the biggest waves could get up to 46 feet tall — a 40 percent increase from 1970s estimates of 33 feet.

Ruggiero said that the study reinforces earlier ones showing similar trends off some other coasts, among them the U.S. Southeast Atlantic, the Northeast Pacific and southwest England. On the other hand, areas like the North Sea and the Mediterranean have shown little to no increase.

Double Whammy

Ruggiero said he’s working on a publishing another study that shows the increase in Pacific Northwest wave heights over the last 30 years “has been significantly more important than sea level rise” in terms of flooding and erosion threats to the coast.

“The bottom line,” Ruggiero said, “is that water levels have already increased in the Pacific Northwest due to wave heights and as sea level rise accelerates the region will experience a ‘double whammy’. So it is critical for engineers and planners to consider both processes.”

Both “winners and losers” are expected in terms of beach stability, with some areas gaining sand, but already some negative effects are visible in coastal towns like Neskowin, Ore.

“Neskowin is already having problems with high water levels and coastal erosion,” Ruggiero said.

“Communities are going to have to plan for heavier wave impacts and erosion, and decide what amounts of risk they are willing to take, how coastal growth should be managed and what criteria to use for structures,” he added.

Ruggiero emphasized that another factor for the Pacific Northwest is that a large earthquake could drop the shoreline by several feet, worsening the impact of extreme waves.

That proved to be the case in Sumatra, Indonesia, during the 2004 quake and tsumani, he said, and some of the shoreline there dropped by up to five feet.

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Ukiah Daily Journal, January 11, 2010

For the first time in 150 years, the city of Fort Bragg in California can claim its own coastline.

On January 5, 2010, the Mendocino County community of 7,000 acquired 92 acres of the former Georgia-Pacific mill site, which stretches for 3 1/2 miles along most of the city’s oceanfront. The city’s newly acquired property will be used for a park and a long-awaited stretch of the California Coastal Trail.

Although the sale is complete, for the next two years, public access will be restricted as plans and development of the parkland and trails takes place and the dream of an open coast becomes a reality.

The city purchased part of its new property using a $4.2 million grant from the State Coastal Conservancy, and Georgia-Pacific donated a 100-foot-wide corridor encompassing over 57 acres along the site’s coastal bluffs for a trail.

The City’s acquisition had been in the works since about the time the mill closed in 2002. Early on, the city worked closely with the Coastal Conservancy and Georgia-Pacific to examine potential uses of the site and a series of public workshops made it clear that local residents were united in their desire for a coastline that is open to the public.

“We have never had the opportunity to open the entire coastline of a city in one fell swoop,” said Sam Schuchat, executive officer of the Coastal Conservancy. “A public coastline in Fort Bragg will be a tremendous recreational and economic asset not just for the city, but for the entire north coast of California.”

The property’s main trail corridor is slated to become part of the California Coastal Trail, which will eventually extend 1,200 miles along the entire coastline of California. More than half of the Coastal Trail is already complete, and new sections are being added in all parts of the state’s coast.

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