Friday, July 23, 2021

The World's Biggest Cities

Urban Agglomerations Worldwide is an interactive map which shows the population size of the world's largest cities. The map uses data from the United Nations to show the size of all the urban agglomerations around the world with a population over 300,000. 

On the map the size and color of the markers show the population size of the city. You can also hover over the circles on the map to discover the actual city population. According to the United Nations data (from 2018) the largest 'urban agglomeration' in the world is Tokyo, with a population of over 37 million.The next largest city is Delhi, with a population over 30 million, closely followed by Shanghai with a population of over 27 million.

For the purposes of the United Nations data set an 'urban agglomeration' is defined as a 'contiguous urban area or built-up area that delimits the city’s boundaries'. Obviously the size of a city's population is partly defined by where you draw its boundaries. For example the top 5 megacities with the largest populations according to Wikipedia are:

  1. Tokyo (38,140,000)
  2. Shanghai (34,000,000)
  3. Jakarta (31,500,000)
  4. Delhi (27,200,000)
  5. Seoul (25,600,000)

Jakarta (3rd on Wikipedia) is ranked on this map as only the 31st largest city by population. Seoul (5th on Wikipedia) is 35th.

Maps (or lists) which rank cites by population therefore often turn into discussions about how you define the boundaries of the ranked cities.Which is why I think it usually makes more sense to map the density of the world's population by area.

You can view a very granular visualization of global population density on The Pudding's Human Terrain map. This interactive visualization shows population density across the globe using 3D population pyramids. 

The taller a pyramid block on The Pudding map then the more people live there.The Pudding has also used its own map to explore in more detail the pattern of population density around the world. In Population Mountains The Pudding examines how unevenly the world is populated and how and why population density can take different forms in different parts of the world.


  • The Urban Agglomerations Map uses United Nations data - (File 12  under the Urban Agglomerations tab)
  • The European Commission's Global Human Settlement Layer (GHSL) also provides spatial information on the physical size of human settlements and on the population sizes of those settlements.

Driving Times from Paris

Time Distance to Paris by Road 2021 in an interactive isochrone map which shows how long it takes to travel by car from Paris to any other location in France. 

An isochrone map uses lines on a map to connect points which can be reached in the same travel time. On Nicholas Lambert's Time Distance to Paris by Road 2021 different colors are also used to visualize areas which can be reached in the same time steps.Because this is an interactive isochrone map you can also select a time period on the map key to view all the areas in France which can be driven to in that time highlighted on the map. For example if you select 60 minutes on the map key then you can see all the areas that you could to travel to in an hour highlighted in blue.

Because Time Distance to Paris by Road 2021 is an Observable notebook it can be forked to work with other locations. For example, Laurent Jégou has forked the map to create his own isochrone map visualizing the Time Distance to Toulouse 2021. Tristram Gräbener has also forked Nicholas Lambert's original map to create a Time Distance to Paris by Train isochrone map.

You can view other examples of interactive travel time maps using the Maps Mania iscohrone tag.

Thursday, July 22, 2021

Canada's Interactive Energy Map

About 67% of Canada’s electricity comes from renewable sources. The vast majority of that (61%) comes form hydroelectricity. Canada is the third largest hydroelectricity provider in the world.The next largest source of electricity in the country is nuclear, which contributes around 15% of Canada's electricity production. 

You can learn more about the different types of electricity source in Canada, including where they are generated and how they are transmitted around the country on Canadian Geographic Education's Interactive Energy Map. The map plots the locations of Canada's significant energy production sites, the major fuel pipe & electricity transmission lines, and Canada's energy processing facilities. The interactive map includes filter controls which allow you to explore each energy sector individually, which allows you to see where the different energy sources in Canada are located in the country.

The Interactive Energy Map paints a rather rosy picture about Canada's contribution to fossil fuel consumption. Although 67% of Canada's own electricity use comes from renewable sources the map doesn't reflect that Canada is also a huge exporter of oil and gas. The Government of Canada for example says that hydroelectricity actually only contributes around 4.5% of Canada's primary energy production. Oil and gas on the other hand make up 57% of the country's primary energy production.


You can explore how America generates power on the U.S. Power Plants map. U.S. Power Plants is an interactive map showing the locations, size and type of America's electric power plants. The map is a great way to see where different types of power plant are located, how much each type of energy source contributes to the country's power supply and how much each source contributes to CO2 emissions.

The number of map filters on U.S. Power Plants means that the map can provide lots of different insights into American power supply. For example the individual fuel filters allow you to see where different power sources are concentrated in America. Select hydro-power and you can see that hydro-power plants are concentrated in the north-west and north-east of the country. While solar power plants are mainly located in California.


Esri's Atlas of Electricity is another great way to explore where the USA gets its electricity from and how it distributes this power across the country. At the heart of an Atlas of Electricity is an interactive map plotting the location and size of the grid's power plants and transmission cables. This map allows you to explore the location and capacity of the country's electricity producing power plants and how they connect to the national grid.

As well as mapping the physical infrastructure of the electricity grid this story map examines the primary energy sources used to generate electricity in the USA. It maps the size and capacity of coal-fired power plants, natural gas power plants and petroleum power plants. Alongside these fossil-fuel sources of power An Atlas of Electricity plots the size and capacity of the U.S.'s nuclear power plants, hydroelectric power plants and solar & wind power plants.

Wednesday, July 21, 2021

The Smoke Forecast Map

The devastating wildfires burning in Canada and the USA are contributing to poor air quality conditions, sparking air quality advisories in large areas of both countries.  The Smoke Forecast map allows you to view a forecast of where in Canada smoke pollution is likely to occur over the next two days.

On the interactive Smoke Forecast map the areas colored brown are forecast to experience high levels of smoke. The darker the color on the map then the higher the ground level concentration of particulate matter is expected to be. The map includes an animation control which allows you to view the smoke forecast for the next 48 hours animated on the map or to select a specific hour to view its smoke forecast.

You can also view the extent of the smoke across north America on NOAA's Smoke Forecast map. NOAA's High-Resolution Rapid Refresh Smoke Interactive map identifies locations with intense fires and forecasts how smoke is likely to disperse based on the latest weather forecasts. The smoke forecast map is experimental. It is prone to errors from cloud cover preventing satellite detection of wildfires and to errors in weather forecasts.

360 Degree Panoramic Maps

The Leventhal Map & Education Center at the Boston Public Library has created some interesting interactive maps from panoramic images in their collection. In Maps that will make your head spin you can view three different historical panoramic sketches as 360 degree panoramic images. 

The panoramic images in this little virtual reality collection include an 1860 360 degree drawing of the Battle of Gettysburg, an 1850's engraving of Boston as seen from Bunker Hill, and the view from Mount Washington as drawn in the early 20th Century.

This isn't the first time I've seen an interesting presentation of the panoramic view from Mount Washington. John Nelson and Jinnan Zhang created an interesting Rotating Bird's Eye View From Mount Washington. In John and Jinnan's interactive version of the Boston and Maine Railroad's map you can rotate the map using your mouse's scroll-wheel. As you scroll on the page the map rotates around its center.

The Birds-eye view from summit of Mt. Washington; White Mountains, New Hampshire was created in 1902 by the Boston and Maine Railroad company. The map shows the view from Mount Washington in New Hampshire. The map numbers all the mountains surrounding Mount Washington and identifies each of them in corresponding lists in each of the map's four corners. What is most interesting about the map is its 360-degree panoramic perspective. The mountain summit and the railroad station are positioned at the center of the map. The surrounding topography is then distorted and wrapped around this central view. 

If you held the map in your hands at the top of Mount Washington and rotated the map to reflect your direction of view you could easily identify each of the mountains in your current vista.

Tuesday, July 20, 2021

100 Years of Plane Crashes

The first fatality in a powered aircraft occurred over a century ago in 1908. The pilot was Orville Wright, the co-inventor of the first ever motorized aircraft. The crash of the plane piloted by Wright resulted in the death of his passenger, Signal Corps Lieutenant Thomas Selfridge.

The ASN Aviation Safety Database records around 22 thousand airplane crashes since August 2nd, 1919. In One Century of Plane Crashes Buğra Fırat explores and visualizes the 22 thousand plane crashes which have occurred over the last 100 years.

Buğra's visualizations of the data includes an interactive heat map which shows where these crashes have occurred around the world. When exploring this map it is important to consider that locations with a lot of air traffic (for example major airports) are statistically more likely to have witnessed the most crashes. To me some of Buğra's other visualizations of the plane crash data are more interesting. For example his timeline of all the crashes from 1919 to 2019 shows how World War II and the Vietnam War were both periods with a higher than normal number of crashes. 

Those of you who obsess over aircraft safety might also be interested in Buğra's visualizations of the number of crashes by plane manufacturer and by the age of the aircraft. However, if you are scared of flying, then you might want to give One Century of Plane Crashes a complete miss.

The Magic Mushroom Map

The Liberty Cap mushroom (Psilocybe semilanceata) usually appears around late summer and early Autumn. I've already seen a few sprouting up on my walks around East London (probably because we have had a wet summer). Which may be why over the last couple of days I've seen a lot of people linking to the Magic Mushroom Map on social media.

The Magic Mushroom Map shows when and where magic mushrooms are likely to be in season. The map was created by matching the dates and locations of historical Liberty Cap growth records with information on habitat and weather. Using this data it is then possible to model when and where Liberty Cap mushrooms are likely to be in season.

The areas shaded red on the interactive Magic Mushroom Map are where the Liberty Cap is likely to be currently in season. If you buy a 'season pass' you can use the map timeline to discover when magic mushrooms are most likely to be in season at your location.

Warning: Magic Mushrooms are listed as a Class A or Schedule I drug in most countries.

If you are interested in foraging for non-psychedelic edibles then you can use the Falling Fruit or Mundraub interactive maps, which show you where you can find fruit trees and other edible plants.  

Monday, July 19, 2021

Street Names & Naming Cultures

Back in 2013 Noah Veltman released his inspired interactive map, the History of San Francisco Place Names.Noah's map provides a fascinating insight into the history of San Francisco street names (click on any of the streets on this map and you can discover how it got its name and who or what it was named for). 

The History of San Francisco Place Names includes an option which allows you to filter the map to view street names in various categories. For example, if you select 'military' you can view all the streets in the city named after soldiers or battles highlighted on the map. 

Noah's map inspired me to create my own Streets of London interactive map, which takes a look at the etymological history of road names in the City of London. This map was also partly inspired by my favorite quiz question 'How many roads are there in London?'. The answer being that there are no roads in the City of London.

There are however a lot of streets, alleys and lanes. The reason that there are no roads in the City of London is that most of the city's streets pre-date our modern use of the word 'road'. The meaning of the word 'road' to indicate a byway did not emerge until the late 16th Century - a long time after most of the roads in the City of London were established and were already named. 

Thanks to Noah I now have a fascinating interest in toponyms. In how places and streets are named, where those names come from and what those names mean. In recent years this interest has been piqued most often by the work of geochicas (and others) to explore how the naming of streets in cities around the world nearly always favors men over women.

The creators of Streetonomics obviously share my interest in toponyms. Streetonomics is a new interactive mapping website which "studies human behavior and cultural trends through the quantitative analysis of street names". 

In simpler terms Streetonomics has created a series of interactive map which allow you to explore and discover more about the people who have streets named after them in New York, Paris, Vienna and London. On these four interactive city maps all the streets which have been named for individuals are shown using different colors. You can click on any of streets on the map to view who the street was named for and learn more about who that person was.

The Streetonomics individual maps for each city include a number of filters which allow you to explore which streets in the city have been named for men and which have been named for women. You can also explore which streets have been named for people from different periods in history, frrm different occupations, and from their country of origin.

If I have piqued your interest in the names of streets and places then you might want to explore the maps posted under the toponym tag on Maps Mania.

The Future Risk of Flooding

The recent devastating floods in central Europe, in parts of America and in New Zealand have obviously led many people to wonder about how susceptible their homes are to flooding. One consequence of global heating and rising sea levels are that flood risks are increasing across the world and the kind of lethal floods seen in Belgium and Germany over the last week are going to become much more common.

Climate Risk's Coastal Risk Map allows you to view your risk from projected sea level rise and coastal flooding by year, water level, and by elevation.Share your location with the Coastal Risk Map and you can view the potential flood risk for different years and for different levels of sea level rise. Climate Central's Risk Zone Map provides additional data for the United States and most Caribbean nations on which populations, infrastructure, and land are most in danger from sea level rise and coastal flooding.

If you don't live by the coast then you can explore your flood risks on the Flood Factor interactive map. Last year the First Street Foundation published their study into flooding risk in the United States. The nonprofit organization also released an online tool that can tell you the current flood risk for your home and how that risk may increase due to environmental and climate change.

If you enter your address or zip-code into Flood Factor you can view a detailed report into whether your area has flooded in the past, the current local flooding conditions and the future risk of flooding. Interactive maps are used by Flood Factor to show the local areas most at risk of flooding and the severity of that risk.

In many countries around the world government agencies provide flood risk maps. The UK government's Long Term Flood Risk Map for England, for example, provides an overview of the chances that any location in England will flood in any year. It shows the chances of flooding from either surface water, groundwater or from rivers or the sea. 

In the USA FEMA's Flood Map Service allows you to view a flood risk map for any address in the country. Enter your address into the Flood Map Service and it will automatically generate a flood risk map, showing you where there are current and future flood risks in the area. The map also provides an overall assessment of the level of flood risk in the area.

Saturday, July 17, 2021

The Sexist Streets of Italy

There are roughly 16,500 streets and squares in Rome. 7,892 of those streets and squares have been named for people. The vast majority of the streets and squares which have been named for people have been named after men. 7,364 of the 7,892 streets in Rome named for people are named after men and only 528 streets have been name for women. This inequality in street naming is repeated in every one of Italy's major cities. 

Mapping Diversity is a fascinating analysis and visualization of the street names of Italy. Using Mapping Diversity you can discover how many streets in Italy's major cities are named for women compared to how many streets have been named after men. The visualization analyzes more than 40,000 streets in the main city in each of Italy’s regions. 

In Mapping Diversity's analysis of Italy's major cities only 6.6% of streets named after people have been dedicated to women. 1,626 streets in total have been named for women in all of Italy's major cities. If you exclude the streets named after female saints then the number is only 959. Of Italy's major cities Bolzano has the highest percentage of streets named for women. However even in Bolzano only 13% of streets named after people are named for women.

Using Mapping Diversity you can view dedicated maps of each main city in each of Italy's regions. On these maps you can view all the streets named for people. You can see how many of these streets named for people in each city have been named for men and how many have been after women. 

You can learn more about the methodology behind Mapping Diversity's analysis and how the maps were created on Finding gendered street names. A step-by-step walkthrough with R

Geochicas has been at the forefront of efforts around the world to reveal the under-representation of women in place-names. Their Las Calles de las Mujeres is an interactive map which reveals all the streets named for men and women in a number of cities in Spain, Argentina, Mexico, Bolivia, Cuba, Paraguay, Peru and Uruguay. 

A number of other interactive mapping projects have explored the sexist culture of naming streets in cities around the world: 

Street Names in Vienna visualizes all the streets named for men and women in the Austrian capital.
From Pythagoras to Amalia analyzes 5,400 Amsterdam street names - including exploring how many are named for women compared to the number named after men.
Recognizing Women with Canadian Place Names shows 500 locations in Canada which have been named for women from lots of different backgrounds. 

In Europe EqualStreetNames has carried out an analysis of the diversity of street names in a number of European cities: