Friday, August 14, 2020

Choropleth Paintings

Earlier this week, while reviewing Map Mercer (which is an interactive map portrait), I joked that "I definitely haven't spent the last few hours trying to work out how to use hexbins to create my own pixelated interactive map portrait". Which of course is exactly what I had been doing.

In fact this week I have spent more than a few hours thinking about how to hexbin a photograph. Or, in other words, how to overlay a hexbin on top of an image and retrieve the color of each hexagon. My thinking is that once you have the color value of each hexagon it will then be a very simple process to overlay the completed hexbin portrait on any location on Earth using an interactive mapping library.

Unfortunately I'm not clever enough to actually code this process. Fortunately, however, the Internet is full of people far cleverly than I am. For example there is Datawrapper's Elana Levin Schtulberg. Just one day after I started wondering about how I would begin to paint pictures on maps Elana published a number of examples of interactive maps which are also pictures. And of course Elana's solution to how to draw pictures with maps is much more elegant than my idea of painting with hexbins.

In Painting by Numbers Elana has created a number of pictures by coloring administrative level geographies as choropleth visualizations. Her examples include London MSOA boundaries colored to create a picture of Big Ben, New York's electoral wards colored to create a picture of the Empire State Building and Berlin's electoral districts colored to create an interactive map painting of the Brandenburg Gate.

Street View of 1940's New York

If you visited Broadway in 1940 then you were spoiled for choice for a wonderful night out. In 1940 Ethel Barrymore was starring in The Corn is Green at the National Theater on West 41st Street. If you didn't like theater, and your tastes ran a little more towards the prosaic, then you could always walk one block up to West 42nd Street, where the Republic Theater had its notorious Girlie Stage Show.

The Republic Theater was Broadway's first burlesque house. It's most famous performer being Gypsy Rose Lee. If a striptease seems a little tasteless then you might have preferred popping to the cinema next door, where the Apollo Theater was showing Mademoiselle Mozart, a French comedy starring the famous French actress Danielle Darrieux.

I know all this because I have been virtually exploring 1940's Broadway on 1940's NYC. 1940's NYC is a fantastic interactive map which allows you to view an eighty year old photograph of any address in New York. Using the map you can explore NYC as it appeared in 1940, just one year before the USA entered the Second World War. These photographs of 1940's New York were taken between 1939 and 1941 by the Works Progress Administration. During these years the WPA took photographs of every building in the five boroughs for the New York City Tax Department.

Broadway in the mid 1980's also had a lot to offer.  Karate Kid Part II was on at the cinema, Cats was being performed nightly at the theater and on Times Square you could buy just about any drug that you wanted. If that sounds appealing to you then get ready to jump into another New York Street View time machine.

80s.NYC is a fantastic collection of vintage photographs of New York City street scenes, all taken in the 1980s. The photos were taken by the Finance Department of New York City in the middle of the 80's. In order to accurately assess building taxes the department photographed every single building in the five boroughs. The pictures could then be used to estimate property values.

Thanks to Brandon Liu and Jeremy Lechtzin you can now travel the city streets of 1980's New York City. Their 80s.NYC map allows you to browse the City's photographic collection by location. Just click anywhere on the map of the city and you can instantly view the vintage Street Views of that location. The map also includes a number of curated 'Stories'. These stories provide historical background to some of the more interesting photos and historical buildings in the collection.

Thursday, August 13, 2020

Where Women Feel Unsafe

Earlier this year Plan International carried out a map survey in four German cities to find out where women in Hamburg, Berlin, Cologne and Munich feel safe and unsafe. The survey revealed that nearly all women have felt unsafe when out & about in these cities. 80% of the places identified in the survey were locations where women have felt unsafe.

Among the reasons why locations were identified as unsafe in the survey were poor lighting on streets and in parks. Women also cited feeling unsafe in locations where men use alcohol or drugs in public. Women also reported feeling uncomfortable while waiting for or using public transport. Bars and restaurants were often reported as locations where women felt safe.

The Safer Cities Map is no longer accepting input but it can still be used to see the locations in Hamburg, Berlin, Cologne & Munich identified by women as being unsafe. Select a city from the side menu and you can view all the locations identified in the map survey. Green pins indicate locations which were identified as somewhere a woman felt safe. Red pins are the locations where women said they felt unsafe. If you click on these map pins you can read the comments left by the woman who identified the location.

You can read more analysis of the Plan International survey at Women experience fear, harassment and violence in their cities (in German). The results of the survey are important not just for city planners in the four German cities surveyed. The results identify common city locations where safety needs to be improved, for example areas with poor lighting and isolated public transport stops and routes.

Women in Brazil who have experienced harassment can share their experiences on the Chegu de Fiu Fiu interactive map. Chega de Fiu Fiu is a campaign against sexual harassment. The campaign includes a Chega de Fiu Fiu Google Map which is used to map the most troublesome and dangerous places for women in Brazil.

Wednesday, August 12, 2020

The 2020 Census Self-Response Rate Map

Currently only 63.4% of households have responded to the 2020 census by phone, internet or post. The U.S. census is carried out every ten years and plays a huge role in how much money is spent in your area on health clinics, educational services and on other important infrastructure. The census is also used for apportioning seats in congress and the number of Electoral College votes your state has.

You can see the self-reporting rates for the 2020 census on the Hard to Count interactive map. Using the map you can view the current state and county self-response rates for this year's census and compare these rates to the self-response rates for the past two censuses. Currently Alaska (49.8%) and New Mexico (53.4%) are the two states with the lowest self-response rates. Although the self-response rate in Puerto Rico at 28.1% is even worse.

Many census experts believe that the Trump administration's attempts to add a citizenship question to the 2020 census (which was overruled by the Supreme Court) may still be suppressing responses to the census in areas with large immigrant communities.

The United States 2020 Census website also maps self-response rates at both the state and county levels. The U.S. 2020 Census map also allows you to compare this year's self-response rate with that of the 2010 census.

This Man is an Island

John Donne famously said that 'No man is an island'. But then John Donne had never met Matthew Mercer. Matthew Mercer is not only an island he is also an interactive map.

Matthew Mercer is an American voice actor. According to Wikipedia he is best known for his work in anime, video games and cartoons. Matthew Mercer is now also an interactive map. Map Mercer is a very strange interactive map in which the face of Matthew Mercer is portrayed like a tropical island in an otherwise empty sea.

Red Giant Maps has used QGIS to turn a portrait of Matthew Mercer into a topographical map. That map has then been made interactive using Mapbox GL. I have no idea why Red Giant Maps felt the need to make a huge interactive map from the face of a voice-over artist. The whole exercise seems a little pointless to me and I definitely haven't spent the last few hours trying to work out how to use hexbins to create my own pixelated interactive map portrait.

Map Mercer is I think the first non-geographical map I've seen use Mapbox GL. Leaflet.js has been used extensively to create map-like interfaces to explore non-geographical images. I recently linked to a few of these non-geographical interactive maps in the post Microscopic Mapping.

Tuesday, August 11, 2020

Driving on Mars

Last month NASA launched a new rocket to Mars. The Mars 2020 mission will deliver the Perseverance rover and the Ingenuity helicopter drone to the red planet. The Ingenuity drone will be used to scout for points of interest which the Perseverance rover will then study. Perseverance is equipped with a number of scientific instruments which it will use to investigate the Mars environment.

Perseverance won't be the only rover on Mars. The Curiosity rover landed on Mars in August 2012, initially for a planned two year mission. Eight years later Curiosity is still operating. During its eight years on Mars Curiosity's cameras have captured over 200,000 images. NASA's Jet Propulsion Lab have turned those photos into a 3D model which is used to study the surface of Mars.

JPL and Google have now joined forces to create Access Mars so that you can also explore the surface of Mars in 3D. Access Mars uses 360 degree panoramic imagery to virtually place you on the surface of Mars. You can move around and visit important locations and learn more about the planet from a narrated tour provided by JPL Mission Scientist Katie Stack.

A number of 360 degree panoramic images of Mars, created using imagery from the Curiosity Rover are also available on 360cities. The screenshot above comes from a 360 degree panorama captured at a patch of flat outcrop called 'John Klein', which was selected as the site for the first rock-drilling activities by Curiosity.

If you open any of the 360cities panoramas of Mars you can navigate around the image just as you would in Google Maps Street View. If you have a virtual reality headset you can even view the panorama in VR.

The Death of the High Street

The Ordnance Survey's High Streets interactive map shows the location of all High Streets (main streets) in Great Britain. 'High Street' is the most common street name in the UK. This map however is not about mapping all the roads named 'High Street' but identifying all the main retail streets in Great Britain.

To be classified as a 'High Street' for the OS High Streets map a road must have a name and be a street which predominately consists of retail outlets. The road must have a cluster of at least 15 retail addresses within 150 metres. For the purposes of this map other retail centers such as retail parks, industrial estates, and isolated shopping centers are excluded.

The OS High Street map is a great resource for finding the main retail streets in Britain's cities and towns. It is particularly useful if you want to assess the health of the country's main shopping streets. For example the Office of National Statistics uses the OS High Street data to explore trends in businesses, employment and those living near high streets.

Yesterday the ONS published its latest analysis into the health of Britain's high streets in High streets in Great Britain. This analysis finds that retail employment in high streets fell in three quarters of local authorities between 2015 and 2018. However employment in pubs & bars and in food services all rose on the high street during the same period. Overall high streets account for 14% of all employment in Great Britain so this year's lock-down is likely to have a huge impact on UK employment. Struggling shops are likely to be adversely affected as are the pub and food services sectors which were previously taking up much of the slack within the retail sector on Britain's high streets.

The OS High Streets interactive map shows center lines, building outlines and bounding boxes of each high street. If you click on a high street on the map you can view its name, how many buildings it contains, and how many of these are shops & how many are offices.

Monday, August 10, 2020

US House Prices Continue to Rise

The U.S. property market is bucking the general economy. Usually when unemployment rates rise house prices tend to stagnate or even fall. However despite the poor economy house prices in the USA continue to rise year-on-year. In July the median price of a home in the USA was 8.5% higher than properties listed in July of last year.

Of course this isn't a uniform trend across the whole of the country. You can explore's interactive Real Estate Price Map to explore the median listing price of properties across the United States. This map allows you to see the average price of a property in each zip-code area. It also allows you to see month-on-month and year-on-year price comparisons. This shows you where median house price listings have fallen or risen in the last month or in the last year.

Pittsburgh, Los Angeles and Cincinnati have seen the biggest year-on-year increases in median house price listings. Miami-Fort Lauderdale-West Palm Beach and Orlando-Kissimmee-Sanford (both in Flrorida) were the only two metro areas in the country to see a year-on year decline in house price listings compared to July of last year.

There are two reasons why house prices may be continuing to rise despite the economic outlook. One reason is the historically low mortgage rate. The other is the decline in newly listed properties. There is a big fall in the number of properties being put up for sale compared to last year. believes that the "lack of newly listed homes on the market, coupled with pent-up buyer demand, is driving inventory to all-time lows and is also steadily pushing prices up higher".

Climate Heat Inequality

By the end of this century, due to climate heating, 75% of the world will have a higher mortality risk from extreme heat. That increased mortality rate will be far higher in the world's poorest regions, where investment in protective infrastructure and care for the vulnerable will not be able to cope with the increased risk of mortality from extreme temperatures.

In Life and Death in Our Hot Future Will Be Shaped by Today’s Income Inequality Bloomberg reports on a new study by Climate Impact Lab which suggests that global heating will result in far higher mortality rates from extreme heat than was previously thought. The study also finds that the world's poorest regions will experience the highest mortality rates from extreme heat.

Bloomberg's article includes an interactive map which shows the estimated change in death rates from extreme heat over the 21st Century. The map reveals that rising global temperatures will result in higher mortality rates. However the highest mortality rates will be in those countries and regions with the lowest incomes. To show the impact of inequality on heat mortality Bloomberg compares regions with similar future climates but very large economic differences. For example, by the end of this century Tehran is expected to have 119 more deaths per 100,000 from extreme heat, while Washington DC (with a similar climate) is expected to have just 32 more deaths per 100,000.

The Bloomberg interactive map shows the predicted increase in mortality rates from extreme heat, not how much extreme heat countries will experience due to global heating. The University of Hawaii has released an interactive map which uses expected temperature increases to predict the number of deadly days we can expect from extreme heat around the world for each year up to 2100. Heatwaves: Number of deadly heat days provides a timeline control which allows you to select any year from 1950-2100. The blue dots on the map show historic extreme heat events that have occurred around the world before 2014.

If you click on the map you can view two charts for the selected location. One chart visualizes the number of annual deadly days over time and the other shows the humidity vs. temperature for the current year.

Saturday, August 08, 2020

The London Building Age Map

In my continuing quest to document every building age map in the world it has been very apparent that towns and cities in the UK do not have many interactive maps showing the ages when buildings were built. While many other countries seem to routinely collect data on the age of individual buildings, national and local governments in the UK really don't seem very interested in documenting the age or construction date of buildings.

This is one of the reasons why Colouring London was created. Colouring London is an open data project from University College London which is being used to collect statistical data on individual buildings in London. Using the Colouring London interactive map anyone can add information about individual buildings in London, including data on building age, the building's original type (residential, commercial etc) and its current use.

Using the Coloring London interactive map you can explore the open data already gathered on London buildings. For example if you select the 'Age' layer you can view a map of all the building ages already crowd-sourced. This map shows individual buildings colored by the year that they were constructed. Some areas of London have so far had more crowd-sourced data collected than others. The building age map at the moment is pretty comprehensive in the West End and the East End. At the time of writing it has little data for South London and most London suburbs.

You can view the ages of buildings in the rest of England & Wales using the CDRC Maps 'dwelling age' layer. The UK doesn't have any open data showing the ages of individual buildings. CDRC Maps has therefore used data from the Valuation Office Agency which does publish building ages in ten year bands (e.g. 1960-70).

The CDRC Maps dwelling age layer allows you to study the geography of residential building ages in towns and cities throughout England & Wales. Buildings built before the 20th Century are all classified by the Valuation Office Agency in one catch all pre-1900's band. Therefore while CDRC Maps is very good for exploring building developments in the 20th Century it isn't particularly useful for exploring the age of buildings built before 1900.