Saturday, May 28, 2022

The Highway Exits of Massachusetts

The animated GIF above shows aerial images of highway exits across Massachusetts. The images were taken from Bird's Eye Cards, a collection of categorized aerial observations of the Massachusetts landscape, created by the Leventhal Map & Education Center at the Boston Public Library.

Lots of round water bodies in Massachusetts

Bird's Eye Cards was created by Garrett Dash Nelson, who has developed some processing tricks for clipping out recognizable patterns in satellite imagery.Using these tools he has put together a number of different collections of these overhead views including the largest buildings in Massachusetts, US state capitol buildings, the roundest water bodies in Massachusetts and highway exits. 

Gerret's Bird's Eye Cards of each category are presented in a grid of images. He states in his write-up that this is a more interesting way to present the images (rather than using rapid animated GIF's which cycle through the images) because it "allows the viewer to identify and explore each one of the images". Perversely I immediately hacked Garret's highway exit images to create the GIF at the top of this post. If you do prefer your aerial images in GIF form Garrett Dash Nelson has actually created an animation of the largest 200 buildings in Massachusetts.

Friday, May 27, 2022

America's Mass Shooting Problem

School Shootings are an almost uniquely American problem. While it is true that school shootings have taken place in other countries around the world, as the map above shows no other country has experienced anywhere near the number of school shootings as the United States. 

This School Shootings by Country 2022 map claims that the USA has experienced 288 school shootings. The country with the next highest number of school shootings is Mexico, with 8. According to Everytown there has so far been 77 incidents of gunfire on school grounds in the United States in 2022, and it is still only May.

Mother Jones has been collecting data on all mass shootings in the USA since 1982 (this data is not confined to school shootings). The map above uses this data to show the location and scale of mass shootings across the country. According to Mother Jones' Guide to Mass Shootings in America in over three quarters of these incidents the guns involved were acquired legally. 

The Gun Violence Archive also collects data on gun-related violence in the USA. The Gun Violence Archive reports that there has been 214 mass shootings in the USA so far this year. So far 658 children have been killed by guns this year and 1,623 have been injured by guns. 

America's response to every mass shooting incident is to pray for the victims. Those prayers never work. Americans keep buying guns and Americans keep shooting each other. Do you want to know what does work - gun controls.

After a gunman killed 51 people in Christchurch in 2019 the New Zealand government banned most semiautomatic weapons. New Zealand also introduced a nationwide gun buyback scheme, which enabled gun owners to safely hand in their guns to the authorities. Since 2019 there have been no mass shootings in New Zealand.

In 1996 a gunman killed sixteen pupils and a teacher in Dunblane, Scotland. Following the incident the UK government outlawed the private ownership of handguns.There have been no school shootings in the UK since the private ownership of handguns was banned. 

It really isn't a difficult problem to solve. If people don't have guns they can't shoot people.

Thursday, May 26, 2022

Polluting the Poor in San Francisco

If you are on a low income in San Francisco then you are probably breathing polluted air. On average the poorest San Franciscans have a 30% higher exposure to nitrogen dioxide than other residents in the city. If you are poor and black then you are probably breathing in even more polluted air. Neighborhoods with high densities of Black, Latino and Asian residents have on average 55 percent more nitrogen dioxide than neighborhoods with mostly White residents.

The Bay Area Air Quality Management District (Air District) and the company Aclima have joined forces to map the air pollution levels in all nine counties of the Bay Area. To achieve this Aclima drove specialized sensor-equipped cars around the Bay Area, measuring the air quality on every public street. The result is air pollution data on more than 5,000 square miles in 101 cities. Providing air pollution data for nearly eight million people.

You can explore the results of Aclima and Air District's survey of air pollution levels on Air.Health, an interactive map which shows air pollution levels at the block level. Enter an address into Air.Health and you can view the individual air pollution levels for Nitrogen Dioxide (NO2), Fine Particulate Matter (PM2.5), Ozone (O3), Carbon Monoxide (CO) and Carbon Dioxide (CO2).

Tuesday, May 24, 2022

Australian Election Maps

Australia's conservative Coalition government has lost power for the first time in nearly a decade. The Labor Party is projected to win enough seats to form the new government and its leader, Anthony Albanese, will become the country's new Prime Minister. At the time of writing, while it is still not clear whether the Labor Party will reach the 76 seats it needs for an overall majority, it has won enough seats to ensure it will be the main party in any minority government. 

The Australian has published an interactive map of the Federal Election Results that is showing which party has won in each seat as the results are announced. One problem with visualizing the results of an election in Australia (as discussed by ABC's in The Australian election map has been lying to you) is the huge discrepancy in size between huge rural seats and more densely populated urban seats. This problem is clearly apparent in The Australian's map of the 2022 election (shown above).

A cursory glance of The Australian election map would probably leave you with the impression that the Liberal Party (blue) was the biggest winners in Saturday's election. Blue covers a huge percentage of the map of Australia - because the Liberal Party has won many of the huge (least densely populated rural seats). The Australian has partly overcome this problem by creating a number of smaller inset maps showing the results in the major cities of Brisbane, Sydney and Melbourne.

The Guardian has used a form of gridded cartogram in its Australian Election Results 2022 - Live Results page. Normally a gridded cartogram uses geometric shapes to represent equal units. In The Guardian's Australian election map the units don't appear to represent anything in themselves but have just been used to make the smallest electoral seats bigger so that they can be seen on the map. So, for example, the geographically small seat of Grayndler in Sydney is represented on the map by four hexagon units. The result is that you can actually find it on the zoomed out map of Australia (in comparison - it is almost impossible to find without zooming in on The Australian's election map).

One result of smaller urban seats appearing larger on the map than their actual geographical areas is that Labor's success in many of Australia's largest cities is a little more apparent on The Guardian map than on The Australian map (where their smaller geographical size undermines their visual impact). Of course The Australian has partly compensated for this by providing three zoomed-in inset maps for Brisbane, Melbourne and Sydney. 

Sydney before and after the 2022 election

ABC News has created a story map, How the Election Result Has Changed Our Cities, which does a very good job of explaining how the Liberal Coalition lost the election by being very unpopular in the largest cities. By comparing election maps from 2019 with the new 2022 results in each of the state capitals ABC is able to show how the Labor Party beat the Liberals in the suburbs, while the independents and the Greens beat the Liberals’ in their inner-city heartlands.


Perth before and after the 2022 election

After comparing the 2019 and 2022 maps in each of the state capitals ABC zooms out to explore the rural vote. Outside of the big cities the Liberal vote held up very well. The Nationals and the LNP in fact managed to retain all their seats in the regions. 

You can view another detailed analysis of How Labor Won in ABC news' cartogram story map, exploring the 2022 results in each state and major city.

Downloading Microsoft's Building Footprints

Microsoft's Building Footprints dataset now contains data on 777m buildings around the world. The data can be downloaded in GeoJSON format and can be used under a Open Data Commons Open Database License (ODbL).

The building footprint data is created by Microsoft by AI detection of buildings from satellite imagery. The map at the top of this post shows where building footprint data is currently available. However Microsoft also has other building datasets available for

Each country's complete building footprint data can be downloaded as a separate GeoJSON file. These individual country files, however, are still very large.Thanks to a Tweet thread by Alsidair Rae I've discovered that you can create custom downloads of smaller sized areas using the UCR-Star interactive map. For example in the screenshot above I have downloaded the building footprints for a small neighborhood in Rome. Instead of downloading the 1.1GB file of the whole of Italy's building footprints from Microsoft I was able to use the UCR-Star map to zoom in on just the area of Rome that I needed and download the visible area on the UCR-Star map. The result is a GeoJSON file size which is a much more manageable 319 KB.

The UCR-Star map also allows you to download Microsoft's building footprint data in other formats (CSV, KMZ, Shapefile and JSON+WKT).

Friday, May 20, 2022

How Election Maps Lie

Tomorrow (21 May 2022) Australia goes to the polls to elect a new government. Ahead of the election and before the results begin to be visualized ABC News has released an interesting analysis of how Australia voted in the last election and what the two main parties have to do to win this election. At the core of this analysis is a discussion of how electoral maps can actually distort the true picture of a national election.

In The Australian election map has been lying to you ABC News looks at the Australian political landscape using an electoral cartogram on which every electoral seat is represented as an equal sized colored hexagon. However, before introducing its Australian electoral cartogram, ABC uses a geographical map of Australia to show how the rural seat of Durack and the urban seat of Grayndler, in Sydney appear on a normal election map. Both areas have one seat in the Australian parliament however on a geographical map Durack covers a huge portion of western Australia, while Grayndler appears as just a tiny dot on the east coast. Of course on ABC's cartogram both seats are showm at the same size. 

Having established the rationale for its electoral cartogram ABC goes on to use its equal sized hexogram to explore Australia's political landscape in terms of geography and in terms of the differences in rural/urban political leanings. Using equal sized hexagons means that ABC are able to easily manipulate its Australian electoral cartogram, reorganizing the map at will. For example, redrawing the cartogram to show how many seats each party has in each state. 

On a geographical map of Australia's political parties the Coalition appears to have a much larger majority than they do in reality. ABC's cartogram shows that the actual breakdown of the current seats held by the Labor Party and the Coalition is in reality much closer. By moving its equal sized cartograms around ABC is able to explore the urban/rural differences in where the two main parties are most popular. It is also able to easily highlight where the most marginal seats are currently located as the two parties go into tomorrow's general election.

Thursday, May 19, 2022

The Deadly Streets of San Francisco

Six times a day, every day of the week someone is injured by a car in San Francisco. A car injures someone approximately every four hours on the city's streets. Around every 13.19 days a person is killed by a car in the city.

The San Francisco Traffic Fatality Map hopes to shame the city's elected officials into action by identifying and memorializing all the victims of car violence in San Francisco. The map shows the locations of every fatal motor vehicle crash on the streets of San Francisco, it identifies the victims of these crashes and attempts to explain the circumstances surrounding each crash.

On the map each identified victim of a motor crash is indicated using a blue circle (the white circle are fatalities where the victims haven't yet been identified). If you click on one of these blue circles you can read more about the victim and how they were killed. The use of names and photos has a huge emotional impact and is incredibly effective in humanizing what might otherwise have appeared as just faceless data. 

However the San Francisco Fatality Map isn't merely a memorial to the city's victims of car accidents. The map also provides data which could be helpful to the city in achieving its Vision Zero objectives. If you click on the map's 'analysis' button you can view a breakdown of San Francisco car fatalities data by date and by location. You can also explore a detailed breakdown of the data by the age and gender of the victims and of the victim's mode of transport. For example this analysis reveals that pedestrians are by far the highest number of people to be killed by cars in San Francisco.

Wednesday, May 18, 2022

Street View of War

The official website of the Department of Tourism of the Kyiv Oblast State Administration are determined to record and document the destruction being caused in their region. In order that no-one is ever able to forgot the crimes committed in the Kyiv region they have established a Virtual Museum of War Memory

The main exhibit in the Virtual Museum of War is a number of custom made Street View panoramas. These 360 degree panoramic images, taken at different locations in the Kyiv Oblast, allow you to take a virtual walk through some of the horrific destruction inflicted by the invading forces. 

The Street View images for each of these virtual tours have also been added to Google Maps. This means that while exploring one of the museum's virtual tours you can click on the 'View on Google Maps' link to reveal the exact location on Google Maps. The 'i' information icon in the top right hand corner of the Street View image also reveals the name of the town where the panorama was taken. 

You can also explore some of the terrible destruction inflicted by the invading Russian army on the incredible 3D models created by Hidenori Watanave on his Satellite Images of Ukraine and 3D Data & 360 Panoramas Map of Ukraine.

These maps use data from images and videos captured in Ukraine to recreate incredible 3D models of some of the devastation caused by the Russian army. 3D photogrammetric models have been created of buildings and vehicles which have been destroyed during the war using drone captured imagery and photos taken on the ground. The result is two shocking interactive 3D maps which allow you to view some of the devastating destruction in Ukraine from an almost first person perspective.

Tuesday, May 17, 2022

Mapping Fire & Flood Risk

Both the Washington Post and NPR have released new interactive maps which allow you to view the risk of wildfire to your home. Climate change means that the chances of extreme weather conditions are increasing for everyone. These extreme weather conditions bring with them increasing risks of wildfire and in some locations increased flooding risk. 

The First Street Foundation has analyzed the wildfire and flood risks for over 145 million properties in the United States. You can check your home's risk from both wildfire and flooding on the foundation's new Risk Factor tool. Enter your address or postcode into Risk Factor and you can view an assessment of your home's wildfire and flood risk based on 'past, present, and future projections'.

The Washington Post has used the wildfire risk data from Risk Factor to create their own interactive map visualizing the risk from wildfire across the United States. The Post's Wildfire Risk Map shows the percentage of properties with 'significant' wildfire risk in each zipcode area in the United States. You can enter your zipcode into the map to zoom to your home. If you hover over a zipcode area on the map you can view how many people live in the area, the percentage of properties currently with a significant wildfire risk, and the percentage of properties which will have a significant risk of wildfire in 2052.

NPR has used the same wildfire risk data from the Risk Factor to create an interactive map which visualizes Where Wildfire Risk is on the Rise. This interactive map shows where the risk from wildfires is likely to increase in the next 30 years at the county level. Because this map shows "the Percent increase in burn probability between 2022–2052" it doesn't actually reveal your wildfire risk. It shows you where in the country wildfire risks are likely to increase or stay the same over the next three decades. It is particularly useful in showing where homeowners have to be aware of the likelihood of significantly rising risks from wildfire.

Monday, May 16, 2022

Geo Sentences

My life is about to get a lot easier.

I waste many, many hours every week editing geographical data in This process often involves having to painstakingly delete individual polygons and lines on an interactive map in order to create a smaller GeoJSON file containing only the geographic features that I actually require. Another time intensive activity I often struggle with is trying to merge two different GeoJSON files into one.

Both of these tasks I can now complete using Hans Hack's new Geo Sentences tool. Hopefully saving me many hours of my working week. Essentially Geo Sentences can take separate GeoJSON files and remove, share dissolve or repair information from the separate geographical data files. 

In the screenshot at the top of this post you can see the GeoJSON file I created by asking Geo Sentences to "Remove the UK from Europe". I created this map of Europe without the UK by uploading two GeoJSON files to Geo Sentences. One file had the geographic border of the UK. The other file contained the borders of all European countries (including the UK). By asking Geo Sentences to "Remove the UK from Europe" I was able to simply and quickly create a brand new GeoJSON file of all European countries except the UK.

Geo Sentences comes with a number of demo GeoJSON files already included. It also provides a number of example sentences which you can use to manipulate your geographical data using these demo GeoJSON files. You can therefore get a very quick understanding about each of the features provided by Geo Sentences by just testing each of the suggested examples sentences with the demo data.