Month: November 2017

Clues in cuneiform

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I just read about some very cool big data archaeology. A group of economists and historians constructed a dataset from 4,000-year-old cuneiform tablets, adding up to hundreds of records of trade transactions between cities. They treated trade volumes as proxies for the distance between cities, presumably calibrated using trade between pairs of cities with known locations. But many of these cities are lost to modern people, and that’s where this gets really interesting: if archaeological site A traded with lost city B, the researchers could plot a radius around A for the likely distance to B. With enough known locations, they can start to narrow down where the lost cities must be:

Narrowing down the location of a lost city

Source: Washington Post. Original paper: Trade, merchants, and the lost cities of the Bronze Age.

What would it take to predict climate change inundation well?

/ climate • gis • seattle • whulj / Comments Off on What would it take to predict climate change inundation well?

Last week I ranted about a poorly executed report claiming to show which properties around the US are at risk of climate change driven flooding. Peter Abrahamsen responded with:

Also, mean sea level, however it’s measured, doesn’t tell you who’s at risk of flooding.

and then pointed me at a couple of much better examples, most notably the Victoria, BC Capital Regional District’s climate change modeling project. I think it’s worth looking at all the other questions that would have to be answered to really get this right. Before diving in, I want to make clear that I’m not piling on Zillow any more: last week’s post was about flaws they should have figured out as a real estate data company, while most of what’s below will be details that they never claimed expertise in or took a position on. Continue reading “What would it take to predict climate change inundation well?” →

Fair Voting Systems map

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I contributed some small pieces of code to the Fair Voting Systems map that Sightline Institute just published:

Fair Voting Systems map screenshot

This was really COREGIS’s project – I just helped Matt with some JavaScript and CSS to handle the complexity of all the intersecting categories they needed to display. But it was fun finally getting to work on something for an organisation I’ve looked up to since first moving to Seattle.

And from the context article, I learned of yet another delightful place name:

A punny sign from Earth, TX

Blindly trusting data will leave you all at sea

/ climate • data crankiness • gis • seattle / Comments Off on Blindly trusting data will leave you all at sea

Zillow recently published a report on how many houses are at risk from sea level rise around the US. It’s a good idea, but looking closely at where I live reveals some… issues in their analysis. Here’s a screenshot from the Seattle Times’ article with the local angle on the report:

Homes that Zillow thinks are at risk of flooding from sea level rise in Seattle

If you know Seattle, you can probably spot the first problem. For those who don’t: the Eastern shore, and the cluster N of the word “Seattle” on that map are all lakefronts, separated from the sea by the rather large Ballard Locks. The local article’s been updated to mention that, but Zillow’s downloadable data hasn’t. And even the local article misses a detail: if sea levels were to rise by a foot more than the analysis assumed, the highest tides would still only be 4¾ inches over the lock gates—a problem for some houses for sure, but nothing like the 7 feet of flooding we’d have on our sea side, and much less than the amount the lake is already allowed to rise and fall by.

But there’s another problem, unrelated to quirks of Seattle’s Herculean engineering, and much more worrying for the reliability of this analysis. Continue reading “Blindly trusting data will leave you all at sea” →