Redistricting—and gerrymandering—is one of the blacker cartographic arts. With the release of data from the 2020 U.S. Census, and the changes in state congressional delegations—some states gain a seat or two, some states lose a seat, others are unchanged—new congressional maps are being drawn up for the 2022 elections. The Washington Post takes a look at proposed congressional district maps in Colorado, Indiana and Oregon, and what their impact may be.

As part of its extensive coverage of the 2020 census, the Washington Post maps the changes in the U.S.’s ethnic/racial makeup, and where it’s been changing.

NASA Earth Observatory has had several stories on the western U.S. wildfires, gathered here. This story summarizes the situation; satellite images of the smoke generated by the fires can be seen here, here and here.

In today's Sunday edition of @washingtonpost pic.twitter.com/qHosujRKrG

— Lauren Tierney (@tierneyl) September 13, 2020

Marena Brinkhurst of Mapbox has a comprehensive list of open data sources relating to the wildfires, smoke, and air quality.

Mark Altaweel at GIS Lounge looks at how GIS is being used to map wildfires, smoke and air pollution.

Previously: California Wildfires, 2020 Edition.

A map of the battlefield of Antietam held by the New York Public Library that shows the location of graves of soldiers killed in the 1862 U.S. Civil War battle is the subject of a piece in today’s Washington Post.

Civil War historians are hailing it as an important new way to visualize the toll of the huge battle outside Sharpsburg, Md., in 1862.

“Every one of us who’s looked at this absolutely flips out,” said Garry Adelman, chief historian for the Washington-based American Battlefield Trust, which works to preserve historic battlefields. “This will reverberate for decades.”

The map is the only one of its kind known to exist. It was digitized by the New York Public Library, which owns it, and was spotted online by local historians a few weeks ago.

The map doesn’t just mark graveyards, it notes the burial locations of specific regiments and brigades—and in 45 cases, individual soldiers.

Last month the Washington Post published a feature on the impact of Interstate 80 on wildlife migrations in Wyoming, and how climate change would affect animals’ ability to move to new habitat as their usual stomping grounds are made unsuitable by global warming. The print version (above) and online version have related maps—one static, one dynamic—that illustrate wildlife paths and how they are stymied by the highway, as well as places where overpasses and tunnels might help. [Lauren Tierney]

Fall foliage maps, which show the best times and places to observe autumn leaves, have been a thing for a good long while. The Washington Post’s take on them is something earnestly next level, with a detailed explanation of the biology and satellite images showing the change in colour across the United States. (I don’t need fall foliage maps: I live on an acre of beech and maple forest and get all the fall colours right outside my window, though here in Canada the leaves are almost all on the ground by now.)

Last month the Washington Post gained access to ARCOS, the U.S. Drug Enforcement Agency’s database of controlled substance transactions, which tracks the path, from manufacturer to pharmacy, of every pain pill in the United States. The Post’s initial analysis found that some 76 billion oxycodone and hydrocodone pills were distributed in the U.S. between 2006 and 2012, that only a few companies manufactured and distributed the bulk of the pills, and some regions of the country were utterly saturated with the pills. That’s where the maps come in: the Post has county-level maps of all this data.

Comparing county-level maps of opioid overdose deaths and pill shipments reveal a virtual opioid belt of more than 90 counties stretching southwest from Webster County, W.Va., through southern Virginia and ending in Monroe County, Ky. This swath includes 18 of the top 20 counties ranked by per-capita prescription opioid deaths nationwide and 12 of the top 20 counties for opioid pills distributed per capita.

Revealing. Damning. Horrifying.

The Washington Post maps the largest of the wildfires burning in northern California: the Carr Fire threatening the city of Redding and surrounding communities. The Redding Record Searchlight has drone footage of the destruction wreaked by the Carr Fire in Shasta County. NASA has natural and false-colour imagery (Earth Observatory, Visible Earth) of the Carr Fire, as well as the Ranch and River Fires to the south, the so-called Mendocino Complex. See the Mercury News’s fire map of the Mendocino Complex, whose two fires’ combined acreage is now larger than the Carr Fire. Meanwhile, German astronaut Alexander Gerst observed the California wildfires from the International Space Station. [San Francisco Chronicle]

I believe other maps of detained children are being produced; I’ll post links as I learn of them.

This map shows every inch of snow that fell on the lower 48 this winter. https://t.co/rSbAYkFEW5 pic.twitter.com/Dg9nLYHcqs

— Post Graphics (@PostGraphics) March 24, 2018

Winter isn’t quite done with us yet where I live. And with that in mind, here’s a neat animated map from the Washington Post that shows the total accumulated snowfall in the contiguous United States. The link includes 48-hour snowfall accumulation maps, satellite imagery, and a map showing which areas of the lower 48 have had more or less snowfall than Washington, D.C. I imagine these maps will have to be updated now.

Reddit user academiaadvice maps the rate of gun homicides per 100,000 residents by state from 2007 to 2016 (above).

From 2015: Business Insider’s map showing, by state, the rate of gun ownership. Note that the two maps do not precisely correlate. [both via Boing Boing]

The Washington Post has maps of Marjory Stoneman Douglas High School in Parkland, Florida—where last week’s shooting took place—and its surrounding area.

In the 1770s British surveyor George Gauld mapped the Florida Keys, taking careful note of the location and depth of Florida reefs. A study published last month in Science Advances compares Gauld’s maps with modern-day satellite imagery and concludes that half of the area occupied by coral in the eighteenth century has disappeared. As the Washington Post reports, the cause of the coral’s disappearance is unclear, though several potential human and natural factors are put forward. [WMS]

Some of the most striking maps of the recent bout of hurricanes have involved the sheer amount of water dropped by these storms. (See previous posts on Harvey and Irma.) Above, a is a short NASA video showing Maria’s track through the Caribbean, dumping water in its wake.

Relatedly, the Washington Post produced maps of precipitation and river gauge levels on Puerto Rico that show just how much water Maria threw at that island.

As they did with Hurricane Harvey, both the New York Times and the Washington Post graphics departments have frequently updated map pages showing the projected path and impact of Hurricane Irma. The Times’ page looks at the hurricane’s current and projected path, threat of coastal flooding, and areas under evacuation, plus some context; the Post maps Irma’s forecasted path on this page and the potential storm surge and evacuation zones on this page, while this page compares Irma’s size to past hurricanes.

The Washington Post maps rainfall and flooding levels in the Houston area.

The New York Times is collecting several maps on two web pages. The first page deals with subjects like rainfall, river level, current and historical hurricane tracks, damage reports, and cities and counties under evacuation orders. Maps on the second page look at Harvey’s impact on the Houston area.

Esri’s U.S. Flooding Public Information Map includes precipitation and flood warnings.

#Harvey in perspective. So much rain has fallen, we've had to update the color charts on our graphics in order to effectively map it. pic.twitter.com/Su7x2K1uuz

— National Weather Service (@NWS) August 28, 2017

Kenneth Field critiques the National Weather Service’s decision to add more colours to their precipitation maps (see above). “Simply adding colours to the end of an already poor colour scheme and then making the class representing the largest magnitude the very lightest colour is weak symbology. But then, they’ve already used all the colours of the rainbow so they’re out of options!”

The Washington Post maps the parts of the United States most dependent on trade—and thus most at risk if the Trump administration starts a trade war with the U.S.’s trading partners.

Today, print subscribers to the New York Times were treated to a fold-out map showing a choropleth map of the 2012 election results at the ZIP code level (above). “The map is part of a special election section that aims to help explain the political geography of the United States — identifying where people who are conservative and liberal live and pointing out how physical boundaries, like the Rio Grande and the Cascade Mountains, often align with political ones,” writes the Times’s Alicia Parlapiano.

Parlapiano’s piece is in fact a lengthy tutorial on how to read election maps, along the lines of the pages I linked to in last week’s post on election map cartography—it outlines the problems of state-level election maps and choropleth maps that privilege area over population, for example, and shows some other ways of depicting the results.

It can’t be a coincidence that in today’s Washington Post we have Lazaro Gamio’s article dramatically highlighting the difference between area and population size with comparative maps. Mark Newman’s cartograms also make an appearance.

I can only conclude that both the Times and the Post are making efforts to educate their readers before the election results start coming in, one week from tonight. (Deep breath.)

The New York Times is mapping the battle for Mosul on this page; the maps show the changing front lines around the city (see above).

Meanwhile, the Washington Post explains the history of Mosul in five maps.

Of all the statistics related to gun violence in the U.S. that could be mapped, this has got to be one of the most bizarre: from the Washington Post’s Wonkblog, the number of times a toddler has shot someone since 2015, by state. [Landon Schnabel]

(Worth mentioning that this is exactly the sort of thing dealt with in Mark Monmonier’s How to Lie with Maps.)