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Alfonso Jimenez via Wikimedia Commons // CC BY-SA 2.0
Alfonso Jimenez via Wikimedia Commons // CC BY-SA 2.0

How San Francisco Is Using Lasers as an Urban Planning Tool

Alfonso Jimenez via Wikimedia Commons // CC BY-SA 2.0
Alfonso Jimenez via Wikimedia Commons // CC BY-SA 2.0

San Francisco’s Market Street is one of the most important transportation routes in the city, but urban planners are looking to reinvent it. Before they can transform the road into a vibrant public space, however, they first need to shower it with millions of laser beams. 

LiDAR technology can be used to generate perfect, three-dimensional maps of cityscapes in a fraction of the time it would take on-the-ground surveyors. In the case of Market Street, San Francisco will be mounting a LiDAR system called a Riegl VMX-250 onto the roof of a truck, from which it will bounce lasers off surrounding surfaces and detect those beams upon their return. To build as accurate a map as possible, the truck will drive the length of the street four times at a speed of 5 mph. Along the way the laser system will construct 3-D point clouds of everything surrounding the truck from overhead wires to fire hydrants. The mechanism is so sensitive that it’s even able to capture the textural differences between pavement and painted parking lines. 

This technology is obviously a useful tool for city planners, but LiDAR also has applications in numerous other fields. Scientists have used it to map topography shifts after natural disasters as well as the destruction of the world’s forests. Earlier this year, Baltimore implemented LiDAR systems to assess damage following its wave of riots. Cities and companies also use the technology to keep track of neglected infrastructure.

In San Francisco, they’re hoping the futuristic mapping tool will help them inject new life into a historic part of the city. That is, unless a little rain gets in their way, as it did this past weekend when the city was forced to postpone the run. When rain drops fall they create noise in the data, leaving a map that's spotty and hard to decipher. The scan has been rescheduled for a weekend in December, weather permitting. 

[h/t: WIRED]

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Why a Train Full of New York City Poop Was Stranded in Alabama for Two Months
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Residents of Parrish, Alabama probably aren't too fond of New Yorkers right now. That’s because the town is currently home to a full trainload of poop courtesy of the Big Apple, as Bloomberg reports. Some 200 shipping containers of treated sewage have been stuck in Parrish for more than two months while the town takes landfill operators to court.

New York City doesn't keep its own sewage sludge to itself, and it hasn't for decades. In the 1980s, New York City was dumping its "biosolids"—the solids left over from sewage treatment, i.e., your poop—into the Atlantic Ocean, where it settled on the bottom of the sea floor in a thick film stretching over 80 square nautical miles. When the government banned the practice of dumping waste straight into the ocean, the city had to get creative, finding a way to get rid of the 1200 tons of biosolids produced there every day.

Enter the poop train. As a 2013 Radiolab episode taught us (we highly recommend you listen for yourself), treated sludge was eventually shipped out to other states to use as fertilizer in the 1990s. After farmers in Colorado began noticing better growth and fewer pests in the fields they grew with New York City's finest sewer sludge, growers in other states began clamoring to take the big-city poop by the train-full, too. That tide has turned, though, and now no one wants the city's poop. Because of the cost of running the program, the train to Colorado stopped in 2010.

Now, biosolids are instead shipped to landfills upstate and in places like Georgia, Ohio, and Pennsylvania, according to The Wall Street Journal. And Alabama. For more than a year, the Big Sky landfill near Parrish has been accepting New York City biosolids, and the locals who have to deal with trainloads of rotting waste aren’t happy.

Normally, the sludge would be loaded onto trucks and then driven the last stretch to get to the landfill. But Parrish and its nearby neighbor of West Jefferson aren't interested in playing host to those messy poop transfers anymore. As the two towns take the landfill operators to court over it, the trains are stuck where they are, next to Parrish's Little League baseball fields. The trainload of sludge is blocked from either being sent to the landfill or back to New York City. While the city has stopped shipping more waste to Big Sky, it essentially said "no takebacks" regarding what they've already sent south. Short of a legal decision, that poop isn't moving.

Needless to say, the residents of Parrish would really, really like to resolve this before summer hits.

Update: Parrish residents can officially breathe easy. The last of the sludge has now been removed from the town, and Big Sky has ended its operation there, according to a Facebook post from Mayor Heather Hall. The containers that remain have been emptied of their smelly cargo and will be removed sometime before Friday, April 20.

[h/t Bloomberg]

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The Self-Deploying Flood Barrier That Could Keep Cities Dry Without Sandbags
MegaSecur, YouTube
MegaSecur, YouTube

For many places in the world, the future is going to be wet. Climate change is already intensifying heavy rains and flooding in parts of the U.S., and it’s only expected to get worse. A recent study estimated that by 2050, more than 60 million people in the U.S. would be vulnerable to 100-year floods.

Some cities plan to meet rising waters with protective parkland, while some architects are developing floating houses. And one company has figured out how to replace piles of sandbags as emergency flood control, as Business Insider reports. Water-Gate, a line of flood protection products made by a Canadian company called MegaSecur, is a self-deploying water barrier that can be used to stop overflowing water in its tracks.

The emergency dam is made of folded canvas that, when water rushes into it, inflates up to become a kind of pocket for the water to get trapped in. You can roll it out across a street, a canal, or a creek like a giant hose, then wait for the water to arrive. In the event of a flash flood, you can even deploy it while the flood is already in progress. It can stop waters that rise up to five feet.

According to MegaSecur, one Water-Gate dam can replace thousands of sandbags, and once the floodwaters have receded, you can fold it back up and use it again. Sadly, based on the flood projections of climate change scientists, heavy flooding will soon become more and more common, and that will make reusable flood barriers necessary, saving time and money that would otherwise be spent buying, stacking, and getting rid of sandbags. The auto-deployment also means that it can be used by a single person, rather than a team of laborers. It could just as easily be set up outside a house by a homeowner as it could be set up on a city street by an emergency worker.

As climate change-related proposals go, it sounds a little more feasible than a floating house.

[h/t Business Insider]

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