Monday, January 26, 2009

The teatime deluge: how a British soap opera sets loose ten Niagara-sized waterfalls every evening

Writing this blog, I'm regularly astounded by the interconnectedness of our post-industrial global economy - a system whose intricate complexities rivals those studied by biologists in wild ecosystems.

Our economy and our global ecosystem aren't just similarly complex - they're intimately related and reliant on each other. This fact riles traditional environmentalists, who lament mankind's peculiar niche, but trying to deny it would require denying that humans live on Earth. We can't understand how nature works without understanding how our economy works. Nor can anyone claim to understand how our economy works without also understanding how our ecosystems work.

For an elegant demonstration of this fact, consider this clip from the BBC, which explains what happens to Britain's electric grid and watersheds as soon as the credits roll on a popular soap opera every evening:

In order to manage the electrical demands of a million tea kettles being turned on at once, then, British utility managers unleash a nightly deluge from reservoirs all over the island. Hundreds of billions of gallons of water are set loose to fall through hydroelectric turbines: it's roughly the equivalent of ten Niagara-sized waterfalls turned on for a few minutes while the tea boils (see the footnote for the math and some mind-boggling numbers).

Ten Niagaras synchronized with the end-credits of the BBC's most popular soap opera: how's that for a spectacle of nature? Doesn't this phenomenon deserve its own national park? Or at least a highway rest stop?

Instead, it's mostly ignored and taken for granted. Even the engineer in this clip seems blithely indifferent to the deluge he's setting loose: entire lakes are reduced to buttons on a spreadsheet at his desk. A power delivery from France fails, but a few clicks and another lake empties out, no big deal.

We might be prone to dismiss this force of nature because it's manmade, but that's precisely the reason we ought to be paying attention to it. Dams, after all, can inflict serious harm on watersheds and fisheries; maybe Britain would need fewer of them if more people were aware of the teatime deluge, and made their own efforts to reschedule their kettle use.

At the very least, knowing that the hydrological equivalent of Moses's Red Sea miracle was being put into the daily service of their tea kettles might lead Britain's soap opera audience to feel more humility and respect towards the natural resources they use, wittingly or not, every day.

* The physics: producing 3 gigawatts of electricity for a fifteen minute period is equivalent to 0.75 gigawatts of work, or 2.7 trillion joules. That amount of energy requires the equivalent of over 700 billion gallons of water (or 2.8 trillion kilograms) falling 100 meters through dams: 2.8 trillion kg * 9.8 m/s2 * 100 m = 2.74 trillion joules.

Niagara Falls is 53 meters tall and pours 150,000 gallons per second, or 135 million gallons in a 15 minute interval. 135 million gallons weighs 511 million kg, so Niagara's water produces 53 m * 511 million kg * 9.8 m/s2 = 265.4 billion joules, or 73.72 megawatt hours of (unharnessed) energy.

Monday, January 19, 2009

Rats prefer Manhattan: an application for biomimicry in urban planning

New research from Tel Aviv University (and reported in Science Daily) finds that cities with grid layouts, like Manhattan, are more rat-friendly than cities with irregular street networks: a gridded system allows rats to cover more territory.

Researchers set up two obstacle courses that followed a grid and non-grid pattern (right, above). The paths the rats took in both courses covers the same distance, but in the grid "city," rats' paths covered much more territory than in the irregular "city."

Quoting from the Science Daily article,
"We've found that routes taken by rats and other members of the animal kingdom tend to converge at attractive landmarks, the same way people are attracted, for example, to the Arc de Triumph in Paris," says Prof. David Eilam from TAU’s Department of Zoology.
The researchers also hope that rat race experiments like this one might be of some use to urban designers as they plan new cities and neighborhoods in the future.

Speaking of rats' love of Manhattan, New York City's Pest Control Services is now indexing their inspection reports on online maps at the new Rat Information Portal, which allows anyone to compare rat inspection data across neighborhoods, community districts, or individual properties. Below, a map of rat inspection results in the Upper East Side. Red parcels indicate properties where inspections found "signs of rats," orange parcels indicate "problem conditions" (such as exposed piles of garbage), and yellow parcels indicate properties that passed their initial inspections:

Friday, January 16, 2009

Update: The Boston Molasses Disaster, Memorialized

Sure enough, the local news section of yesterday's Boston Globe included a 300-word blurb about the molasses flood of 1919 (which I wrote about on Monday) to commemorate its 90th anniversary:

90 years later, Molasses Flood continues to generate buzz

And now, the story can slumber for another decade, until the big centennial.

Wednesday, January 14, 2009


Cheonggyecheon is a small stream that once flowed from a cirque of mountains that surround the historic center of Seoul into the Han River, 6 kilometers away.

In the years immediately following the Korean War, Cheonggyecheon was overrun by informal refugee camps, shantytowns, and sewage. The stream was soon paved over for a wide boulevard; in 1968, during Korea's own urban renewal fad, an elevated highway was stacked above the road. In spite of its historic and cultural significance to Korea, Cheonggyecheon spent over half a century in an underground culvert, choked with filth.

Then, in 2003, in an act of political will that seems miraculous to me, Seoul mayor Lee Myung-bak began a project to remove 16 lanes of stacked expressway and restore the lost stream beneath. Two years later, a vibrant, wild park had replaced a traffic-choked freeway. Believe it or not, the two photos above show the same section of stream (the two buildings in the center-right of the top photo, taken sometime early in the 2000s, are the same two buildings on the left side of the bottom photo).

Tearing out a huge downtown freeway didn't create mass gridlock, as the project's opponents had promised: traffic actually moves faster and more smoothly today than it did when the freeway was there. In an interview with the Guardian two years ago, Kee Yeon Hwang, a professor of urban planning, said that "as soon as we destroyed the road, the cars just disappeared and drivers changed their habits. A lot of people just gave up their cars. Others found a different way of driving. In some cases, they kept using their cars but changed their routes." In other words, people aren't as stupid as traffic engineers think they are. Koreans gave the project a definitive seal of approval when they gave Lee Myung-bak, the project's primary political champion, a promotion to the presidency in 2007.

By replacing idling cars with a naturalized waterway, Seoul also lowered summer temperatures in the center of the city and improved air quality and circulation. The Cheonggyecheon isn't yet a functioning watershed: the water flowing from the "headwaters" in the center of Seoul is currently being pumped uphill from the Han, instead of trickling down from the mountains. But it's still attracting wildlife, including fish and herons, and there are more plans in the works to restore elements of the stream's natural hydrology.

Of all the parts of the park I've looked at, this one's my favorite: three remnant highway abutments standing in the middle of the stream like a utopian apocalypse scene - a glimmer of hope that the brutal regime of freeways and highway engineering is losing its grip on the world's cities. Credit for the photo goes to Flickr user Ben Harris-Roxas:

Monday, January 12, 2009

The Boston Molasses Disaster

Image: Wikimedia commons
. The January 16, 1919 edition of the Boston Post.
90 years ago, one of the more spectacular urban disasters in American history struck Boston's North End: the Great Boston Molasses Flood.

On January 15, 1919, a rapid rise in temperature probably caused an increase in pressure inside the Purity Distilling Company's 2.3 million-gallon storage tank on Boston's waterfront. As pressure inside the tank increased, eyewitnesses reported hearing a sound like a machine gun firing as the tank's rivets popped out, and feeling the ground shake as a 35-foot-high wave of molasses burst out into the neighborhood.

The flood killed 21 people and numerous horses. It also injured 150, and leveled several city blocks. In the disaster's aftermath, knee-deep swamps of molasses hampered rescue efforts substantially. The Harbor was brown with molasses through the following summer. And the city smelled like molasses for decades afterward: some say that on hot days in the North End, you can still smell it. Reporter Edward Park wrote about the disaster in a 1983 article for Smithsonian magazine (link):

As a boy, I never questioned that odor, so strong on hot days, so far-reaching when the wind came out of the east. It was simply part of Boston, along with the swan boats in the Public Gardens and the tough kids swimming in the Frog Pond on the common. But years later, when I was on the staff of the Boston Globe, I asked a colleague about it. We were walking over toward the North End, beyond Hanover Street, and our taste buds were guiding us toward one of the corner trattorias where North End Italians make, I swear, the world's finest pizza, and for once I was annoyed by that other smell - the Boston smell.

"Why does Boston smell of molasses?" I asked my friend.

He looked at me curiously. "Because of the molasses flood, of course," he said.

I regret that I've never smelled it myself, but I'll try harder to the next time I'm in the neighborhood. Park also goes on to write that his old employer, the Globe, did short memory pieces every ten years to commemorate the event. The molasses disaster was to Boston in 1919 what the I-35 bridge collapse was to Minneapolis in 2007, or what the urban fires of 1976 were to East St. Louis: a spectacular tragedy that the city would never forget, until, inevitably, almost everyone forgot it.

Park's account was written over twenty five years ago. Has the Globe's interest in memorializing the disaster on each ten-year anniversary faded, like the distinctive smell? Or will another item on the molasses flood run in Thursday's newspaper? I'm hoping for the latter, and will post a link here if I find one.

The aftermath, looking east along Commerical Street towards the Charlestown Bridge. The vaguely cylindrical remnants of the destroyed molasses tank are visible in the upper center of the photo, in front of a largely intact warehouse building. Today, the site is a public park, with a memorial plaque.

Read more about the molasses flood from the Massachusetts Humanities Council...

...and from Wikipedia, which includes the names, ages, and occupations of the disaster's 21 victims.

Wednesday, January 07, 2009

The Foreclosed Backyards National [Skate] Park

Photo: New York Times

Last summer, I'd written about how Sun Belt swimming pools were reverting to semi-wild conditions in abandoned backyards thanks to the foreclosure crisis. Suburb-dwellers, so accustomed to a landscape of control, are seeing their swimming pools transform into vernal pools. Quoting a Wall Street Journal article on the phenomenon:
"First you have fish, then you have birds that eat them" and then bird droppings, says Arnie Shal, a retired accountant, who lives next to several foreclosed houses with pools in Clearwater, Fla. "It's not really a healthy situation."
But it certainly is a healthy situation for fish and birds, of course. The foreclosure crisis is turning suburban backyards into tiny little wildlife refuges.

Unless you're interested in fishing for minnows or birdwatching, though, the foreclosure vernal pools don't offer a lot in the way of backcountry recreation opportunities. Which is why I'm so happy to learn, via the New York Times, of another burgeoning trend: reclaiming foreclosed backyards and their drained swimming pools as skateboard parks.
"There are more pools right now than I could possibly skate," [skater Adam Morgan of Los Angeles] said. "It’s pretty exciting." Mr. Peacock travels around town in his pickup searching for the addresses of homes he has learned have been foreclosed on, either via the Internet or from a friend who works in real estate. He has also learned to spot a foreclosed house, he said, by looking for "dead grass on the lawn and lockboxes on the front door."
California's abandoned backyard pools are thus becoming a world-renowned landmark for suburban outdoor recreation: "Skaters are coming to places like Fresno [a Central Valley city with a preponderance of foreclosed backyard pools] from as far as Germany and Australia."

So, not only are our foreclosed suburban backyards becoming new havens for wild nature; they've also become world-renowned playgrounds for outdoor sports. And, thanks to the passage of the massive bailout package and the "troubled asset relief program," the American public now owns a substantial portion of these over-mortgaged backyards.

America's foreclosed backyards are a lot like a newly-created national park.

Photo: New York Times

The skateboarders have even developed their own code of ethics, which is strikingly similar to the "leave no trace" principles that are promoted among backcountry hikers and climbers. Quoting once again from the Times article:
In order to maintain a sense of public service, the skateboarders adhere to basic rules: no graffiti, pack out trash and never mess with or enter the houses. [Skating occurs] in short bursts during the workday to avoid disturbing neighbors or attracting police attention. Twice in recent weeks, Mr. Peacock said, the police caught the skateboarders in an empty pool and demanded they leave but did not issue citations.
So, skate Chlorine Canyon! Try angling in the Fresnoglades! Learn about the family life of opossums, raccoons, and other small mammals in the Pool Shed Game Preserve! Just remember to leave the Park as you found it, and please respect other visitors.

No matter where you live, a piece of the Foreclosed Backyards National Park is nearby... start planning your vacation today!