Joseph B. Treaster: Water and The World

A Continuing Discussion on Water and People on A Warming Planet

Jun 10 2010

Bracing For Flooding At Hurricane Time In Already Soggy Florida

Published by Joseph B. Treaster under

WEST PALM BEACH, Fla.—Around the clock, from a control room on the edge of the Everglades, technicians track water levels in the canals, lakes and marshes across the southern part of Florida. On their computer screens, they can see changes hundreds of miles away and with a few key strokes they open and shut flood gates.

The flood controls in South Florida are among the most sophisticated in the world and they get a workout most summers. Summer is the wet season here, a time of downpours so dense that you can see no more than 50 or 60 yards. Summer is also the time of hurricanes and tropical storms. And those wind machines can dump a lot of rain.

This summer forecasters are predicting a busier than usual storm season with as many as 14 hurricanes. Floods and storm surge, a kind of tidal wave that hurricanes sometimes push across beaches, kill more people in hurricane season than the wind. The wind gets the headlines, the water brings out the undertakers.

No one knows where the storms will come ashore. But this could be a very bad year for South Florida. The land is soggy from more rain than usual in the months leading up to hurricane season and it would not take much to cause flooding. The biggest flood threat in the region is Lake Okeechobee, the wide, shallow bowl of water about 45 miles west of here. The water in the lake, one of the largest in the United States, is already high and experts worry that the lake’s earthen, 35-foot-high dike might not hold.

Killer-floods are not routinely heavy on the minds of the technicians in the control room of the South Florida Water Management District here. A few feet of water may rise in backyards and parking lots and push into houses and shops and offices and the ground floors of condos. It can make life miserable and expensive for the 7.5 million people packed into South Florida, and for the farmers and ranchers working the land back from the coasts. The costs can quickly get into the hundreds of millions of dollars. But deaths are rare. Trouble at Lake Okeechobee, however, could be a nightmare.

Nothing awful has happened at the lake in more than 80 years, but memories are still vivid of the flooding in two hurricanes in the 1920s. Several thousand people died. In the worst Lake Okeechobee flood, in 1928, high water covered a stretch of 75 miles of the flat, Florida landscape. Some of that land is still Everglades swamp. But much of it is now thick with houses and shopping centers.

Since the early 1980s, concerns about another disaster at Lake Okeechobee have been growing. Water has been seeping under the 143-mile- long mud, gravel and rock dike that the United States Army Corps of Engineers began building in the 1930s. A report four years ago by the South Florida Water Management District said the dike posed “a grave and imminent danger to the people and the environment of South Florida.” Portions of the dike, the report said, “bear a striking resemblance to Swiss cheese.”

The Corps of Engineers began reinforcing the southeastern wall of the dike, which is considered the most hazardous section, three years ago. But about half of the work in that 22-mile stretch remains to be done.

The water in the lake was at about 14.5 feet in early June or about two feet higher than what the Corps of Engineers and the water district consider prudent. The higher the water gets, engineers say, the higher the probability that the dike will give way and release an avalanche of water. Perhaps 60,000 people live south of Lake Okeechobee where flooding is most likely.

“It would probably kill many, many people,” said Eric Buermann, the chairman of the governing board of the South Florida Water Management District. “You could have a lot of flooding in downtown Fort Lauderdale.”

Twice in the mid-1990s, water in the lake rose to more than 18 feet. The dike did not yield. But Nanciann Regalado, a spokeswoman for the Corps of Engineers, said that at 17.5 feet “we get very, very concerned.” At 19 feet, she said, the authorities would be considering evacuation.

Trying to keep the lake from rising further, the Corps of Engineers and the water district have been flushing water from the lake into two main rivers and into huge holding ponds in the Everglades. But it rains almost every day around the lake and the rest of South Florida in June and early July and the pumps struggle to keep up. The engineers say that in the most intense rains, the kind that come with hurricanes and tropical storms, the lake can rise six times faster than the pumps can draw down the water.

“We’re concerned,” Mr. Buermann  said in an interview. “We’re taking measures to address this. But if you have the ultimate storm with wind pushing that water, the force of that water on the dike, anything could happen.”#

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May 28 2010

Telling It Like It Is On Killing Power Of Weakest Hurricanes

Published by Joseph B. Treaster under

FORT LAUDERDALE—Summer time. Hurricanes. This year, with a very busy hurricane season coming up – according to government and university experts—the National Weather Service wants to set a few things straight.

For nearly 40 years, government forecasters have been describing hurricanes in the dispassionate, clinical terms of engineers and meteorologists.

Now the forecasters have rewritten the guidelines on hurricanes to make the impact of high winds more vivid. And they may end up scaring the daylights out of people.

The forecasters have thrown away terms like minimal, moderate and extensive damage and now starkly warn that even the most modest hurricanes can savagely dismantle mobile homes, shatter windows, rip off roofs, kill and maim. The most severe storms, the new guidelines say, are very likely to leave parts of towns and cities “uninhabitable for weeks or months.”

You already knew hurricanes were bad. But you have never heard it so clearly from weather central. Now the forecasters are saying, enough with restraint, enough with ambiguity. Let’s try telling it like it is.

“This might scare people,” said Bill Proenza, the regional director for the southern United States for the National Weather Service. But, most of all, he said, it might motivate them to put up shutters, tie down lawn furniture and show a little respect for even the lowly Category 1 hurricane which, with winds as low as 74 miles an hour, has done its share of killing and wrecking. Hurricane Katrina, for example, was a Category 1 when it sliced across Florida in 2005 and it wreaked $1 billion in damage.

This could be a terrible hurricane season. The National Oceanic and Atmospheric Administration says that up to 14 hurricanes could develop during the six-six month season from June 1 to Nov. 30 and that as many as seven of them could become major storms. A big hurricane could spread the BP oil spill across a wider swath of the Gulf of Mexico. Federal Emergency Management officials say that as little as several days of heavy rain on the periphery of a hurricane could create a new disaster for the one million Haitians still living in tents after the earthquake in January.

The forecasters worry that the tens of millions of Americans living in the hurricane zone, mostly along the southern coasts, may not be taking hurricanes seriously. One reason more than 1,800 people died in Hurricane Katrina in Louisiana and Mississippi, storm experts say, was that many shrugged when they should have been boarding up their homes and heading for higher ground. The awful memories of Hurricane Katrina may be fading, the forecasters say, especially after last hurricane season when not a single powerful storm made landfall in the United States.

“Complacency is always a problem,” Mr. Proenza said in an interview here during a break in the annual Florida Governor’s Hurricane Conference in late May.

People who are newly arrived in the hurricane zone, those who have been on the fringes of big storms and others who have lived all their lives along the coasts, but never endured a hurricane, are the most likely to ignore storm warnings and end up in trouble, the experts say.  “They really don’t comprehend the full potential impact of a hurricane,” Mr. Proenza said.

So after nearly 40 years of referring to hurricanes in low-key generalities, the weather service has decided to try something new. “We wanted to provide a realistic portrait of what winds can do,” said Chris Landsea, the Science and Operations officer at the National Hurricane Center near Miami. Mr. Landsea led a team of experts who rewrote what used to be known as “The Saffir/Simpson Hurricane Scale.” The guidelines are published on Internet sites around the world, distributed by emergency managers and referred to by journalists in their reports. The new guidelines were issued without fanfare in March and revisions were being made well into May.

The new name for the government guide that describes the five categories of hurricanes is “The Saffir-Simpson Hurricane Wind Scale.” Hard to see the difference? One big feature of the new guidelines is what you can’t see.

The whole project got started because complaints had been growing, both among experts and among ordinary Americans, that “The Saffir/Simpson Hurricane Scale” was misleading on storm surge, the wall of water that often slams ashore in a hurricane with the force of a bulldozer and that over the years has killed many more people than wind.

According to Saffir/Simpson, which was introduced in 1972, A Category 3 hurricane with winds of up to 130 miles an hour should create a storm surge of up to 12 feet. Katrina came ashore in Louisiana and Mississippi as a Category 3 hurricane and was pushing a wall of water nearly 30 feet high. Three years later, Hurricane Ike hit the Texas coast as a Category 2 hurricane with a 20-foot-high storm surge, more than three times greater than anticipated by Saffir/Simpson.

The forecasters’ solution was to yank the information on storm surge from Saffir/Simpson. So it is no longer a hurricane scale with guidance on both wind and storm surge. The new Saffir/Simpson deals only with wind, hence the new name, “The Saffir-Simpson Hurricane Wind Scale.” Now, on storm surge, the forecasters are going to be creating tailor-made estimates for each hurricane as it develops, working with a wide range of variables including one of the most important, the shallowness of offshore waters. The shallower the water, the bigger the storm surge.

Forecasters have routinely warned in commentaries that Category 1 hurricanes should not be disregarded and they have been offering their own calculations on storm surge. But their remarks and calculations have been contradicted by storm descriptions in official documents.

Strictly speaking, hurricane experts say, the descriptions were not wrong. But they were not clear either. “The winds in a Category 1 hurricane are about the same as the winds in a severe thunderstorm, a little higher,’’ Bill Read, the director of the National Hurricane Center told me. So in a sense you could say, as the old Saffir/Simpson did, that the winds might cause minimal damage. “But,” Mr. Read said, “the thunderstorm winds might last for one to 15 minutes. The same winds in a Category 1 hurricane last for hours and can have a tremendous impact.” #

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Jan 14 2010

The Texas Drought, The Florida Chill—Climate Change? No

Published by Joseph B. Treaster under

MIAMI—That drought that just ended in Texas was not an example of climate change. Neither were the weird, freezing cold temperatures in Florida as the year began.

How confusing. You hear so much about climate change. Then you see what looks like evidence. And it turns out not to be evidence at all.

“Climate change is slower than that,” said Dr. John Nielsen-Gammon, a professor at Texas A&M University and the state climatologist in Texas.

Much slower. It is a decades-long process, a long, slow march that is hard for many people to grasp. Widespread confusion over short-term fluctuations and long-term trends worries the majority of scientists who are convinced that climate change is happening. They say it leads to apathy, inaction, a do-nothing approach, that could prove to be very harmful.

“People say, obviously, we don’t really understand this, so we need to wait until the uncertainty is gone,” said Don A. Wilhite, the director of the School of Natural Resources at the University of Nebraska-Lincoln, in an interview. “But the uncertainty will never be gone. If you wait 25 or 30 years to do something, then it’s basically too late. If everything we are learning is correct, we need to be doing something now.”

The short-term fluctuations in the weather – like the drought in Texas and the cold spell in Florida - are caused by historic cycles and so-far inexplicable random episodes, scientists say.  They may contribute to long-term averages.  But the fluctuations often contradict the big picture. The confusion is aggravated when you hear from the handful of scientists who earnestly believe there is no such thing as global warming and climate change.

Recent polls justify concern. A year ago, 80 percent of those surveyed by the Washington Post and ABC television said they thought climate change was happening. But as 2009 ended, the percentage had shrunk to 72. The Pew Research Center for the People & the Press in Washington found even less public confidence. It recently got a positive response on climate change of 57 percent, down from 71 percent a year earlier.

Some scientists despair at ever getting people to understand climate change.  But Michael J. Hayes, the director of the National Drought Mitigation Center, another unit of the University of Nebraska, said, “You can’t just say, ‘Let’s forget about it.’”

Dr. Hayes and scientists who recently assembled at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, advocate putting more effort into finding clear and simple ways to demonstrate that short term changes in the weather and long-term climate conditions are two different things. Or as Dr. Hayes’ colleague, Dr. Wilhite put it, today’s cold snap does not mean that “climate change is a hoax.”

At the Rosenstiel conference, Ben Kirtman, a University of Miami professor, suggested that public support might be increased if people did not have to envision dire consequences many decades into the future – in some cases long after their likely death.  “We really want to get into the question of what’s going to happen in the next 10 or 30 years,” Dr.  Kirtman told the conference, according to the Miami Herald.

Lisa Goddard, a scientist at the International Research Institute for Climate and Society at Columbia University, who also spoke at the conference, said in an interview that studies that distinguished more clearly between “natural variability” in the short run and “man-made climate change” could not only reduce public confusion but also could be useful tools for government officials, farmers and others.

Texas has been through lots of droughts. The latest one, which began to manifest itself in early 2008, was the worst since the 1950s. But five droughts hit the state between 1996 and 2006 alone. The latest one cost farmers and ranchers more than $4 billion, according to state officials.

One of the driving forces in the Texas drought was the way things developed in the Pacific Ocean. Water temperatures in the Pacific were cooler than usual in late 2007 and through late 2008 in what is known as the La Niña effect.  La Niña reduces rainfall over Texas.  Last fall, the cycle shifted to El Niño. That brought rain to Texas and the drought was broken.

During the Texas drought, temperatures rose into the high 80s Fahrenheit or four to six degrees above average. “That made the climate projections” for the future “more real,” Dr. Nielsen-Gammon said. “People were able to feel what a hot summer would be like.”

That is one benefit of a shock like the Texas drought. Even though it is not evidence of climate change it gets people thinking about what lies ahead.

The New York Times captured the Texas drought and its dénouement in two photographsOne showed a sweep of dry, cracked Texas ranch land.  The other focused on the same terrain. But now there was bright green grass in the foreground, a good-size lake in the middle and more greenery beyond the lake. A family of cowboys and ranch women and young ones was lined up on the grass with their horses. The second picture so captured the sense of renewal and joy that, according to The Times, the family sent it out as their Christmas card. #

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