Monday, November 18, 2019

Greece's Refugees

In the last few months the number of refugees arriving in Greece has surged. Greek refugee camps are now filled beyond capacity. For example there are currently around 16,924 immigrants on Lesbos. The island is equipped to host around 3,000 refugees at most.

The UN Refugee Agency's Operational Portal has an interactive map visualizing the number of refugees arriving on each of Greece's islands. The map is accompanied by a series of graphs showing the total number of arrivals in Greece in 2019 by land and by sea. So far this year there have been a total of 59,448 refugee arrivals. 16,861 of those were from Afghanistan and 12,452 originally came from Syria.

You can read more about the conditions in Greece's overcrowded migrant camps on the UN Refugee Agency's article Lone Children Face Insecurity on Greek Island.

The UNHCR data on refugee movements is available under a Creative Commons license and has been used in many interactive maps. You can view a number of these mapped visualizations of refugee movements in The Movement of Refugees Around the World.

The Hong Kong Tear Gas Heat Map

Currently the map is showing a lot of activity around the Hong Kong Polytechnic University, where police have trapped hundreds of activists. The police have today been firing tear gas canisters at demonstrators who have gathered to protest at the police siege of the campus. Just yesterday the creators of the crowdsourced Hong Kong police tracking map, released a heat-map visualizing the locations where tear gas has been deployed in Hong Kong from August 5th to November 15th. is a crowdsourced map which reports the live position of the police in Hong Kong. On the map different emojis are used to show the location of the police across the city. Registered users can use the Telegram messaging application to report locations where the police are currently using violence against protesters. The application is widely used by Hong Kong residents who wish to avoid the violent clashes between the police and protesters in the city.

The Tear Gas Deployed in Hong Kong static map is a crowdsourced map showing where the Hong Kong police have fired tear gas. It is important to note that the heat-map doesn't show the actual number of tear gas canisters fired by the police. The heat-map intensity is instead based on the numbers of users who have reported a tear gas canister fired at a location. It is still useful therefore in helping to identify the locations in Hong Kong which have witnessed the most violent clashes between the police and pro-democracy protesters.

Saturday, November 16, 2019

The Biggest Plastic Polluting Brands

In September volunteers around the world took part in an audit of plastic litter. Nearly half a million pieces of plastic waste were collected in 51 different countries. 43% of those individual pieces of plastic were clearly marked with a consumer brand. The top global plastic polluter around the world, according to the audit, was Coca Cola. This is the second year in a row that Coca Cola was the largest plastic polluter, based on the results of the World Clean Up Day audit. 11,732 pieces of Coca Cola branded plastics were found in total. This is more than the next three top brands combined.

The Biggest Plastic Polluters interactive map allows you to view the levels of plastic found in countries around the world. The map uses colored scaled markers to show the amount of plastic picked up in all 51 countries who took part in the audit. You can view the 'Grand Total' of all plastic found in each county or view maps of the 'Coca Cola', 'Nestle', or 'Pepsi' branded plastics found in each country.

The map itself you can take with a pinch of salt. Obviously the totals found in each country are somewhat dependent on the number of volunteers who took part in the audit in each country. The largest markers therefore don't necessarily show the countries producing the largest amount of plastic waste. However it is interesting to see how much the different branded plastics make up of the total number of plastics found in each country.

The Ocean Cleanup probably provides a more scientific assessment of plastic pollution levels around the world. The Ocean Cleanup claims that "80% of river plastic pollution entering the world's oceans stem from 1000 rivers". In Plastic Sources the organization has mapped out what they say are the world's 1,000 most polluting rivers and the 30,000 rivers responsible for the other 20% of the plastic entering our oceans.

Currently the map includes very little information on how the organization calculates the amount of plastic waste distributed by each river or how they determine which are the most polluted rivers. The organization says that their model is based on data on 'plastic waste, land-use, wind, precipitation and rivers' but not where that data comes from. It does say that "Detailed information on our modeling approach and data will follow in our scientific update."

Litterbase is another organization which is attempting to determine the source of the plastic pollution found in the world's oceans. Currently Litterbase provides a summarized overview of the results from over 1,900 studies into the amount and composition of litter and its effect on marine environments. An example of one of these summaries is Distribution of Litter Types in Different Realms, which is an interactive map created from the results of 916 scientific publications on the amount, distribution and composition of litter in the world's oceans.

There are gaps in our knowledge where little scientific research has taken place, for example around Africa and the Polar regions. One way that we can fill in these gaps in our knowledge is by modeling the density of pollution in the oceans based on the results of scientific studies. Sailing Seas of Plastic is a dot density map which shows the estimated concentration of floating plastic in the oceans based on the results of 24 survey expeditions (2007-2013) and on wind and ocean drift models.

Each dot on the Sailing Seas of Plastic map represents 20 kg of floating plastic. According to the map there are 5,250 billion pieces of plastic adrift on the seas of the world. If you want you can also overlay the sailing tracks of the 24 survey expeditions on top of the dot map.

Friday, November 15, 2019

The Moscow Building Age Map

While there have been lots and lots of interactive building age maps released over the last few years very few of these maps have been used to explain the history of construction within individual cities. This is a real shame because these maps obviously have important stories to tell about how towns and cities have developed over time.

That is why I really like the History of Moscow Housing on an Interactive Map. The History of Moscow Housing on an Interactive Map is an exploration of how housing has developed in the Russian capital over the last few centuries. On the map individual buildings are colored to show their year of construction. It is also possible to select individual buildings on the map to view the year that they were built. The time slider at the bottom of the map allows you to view houses built during different time periods.

As well as the interactive map the article includes a graph showing the number of residential houses built in Moscow by year of construction. This graph reveals that the post-war years of 1950-1980 were the most active years for residential development in the capital. Under Khrushchev there was a big drive to construct new homes in Moscow. Under Brezhnev, the pace of construction declined and continued to decrease until the mid-1990s.

The History of Moscow Housing on an Interactive Map was built with the help of Yandex Real Estate. The real estate company says that the age of a home has a big influence on a property's popularity with buyers and/or tenants.

This isn't the first time that Moscow's building ages has been mapped. Mercator's Houses of Moscow also maps the ages of all of Moscow's buildings.

There Are No Streets in Crawley

Since September I've been trying to prove a theory that there are very few new streets in Britain. My theory is that very few roads built after 1800 are called "... Street". Britain has lots of post-1800 roads, avenues, closes, courts and lanes. I believe it has very few new streets. For some reason since 1800 town planners in Britain have taken a strong dislike to calling roads '... Street'.

Today's #30DayMapChallenge is to create a map related to names. I've taken this as an opportunity to put my street theory to the test by exploring the number of 'Streets' and 'Roads' in a UK town largely built after 1800. The new town of Crawley in West Sussex was developed after the Second World War. If my theory is true it should therefore have very few roads names 'Street'.

There Are No Streets in Crawley is an interactive map which colors all roads in Crawley yellow and all streets red. Of the hundreds of roads in Crawley only five of them are named as streets: 'High Street', 'Church Street', 'West Street', 'New Street' and 'Ifield Street'. I don't know old these streets are  but I think all five of them existed before the new town of Crawley was built. I believe all five streets in Crawley can be found on this 1896 Ordnance Survey Map. It is therefore very likely that all five of them pre-date 1800. On the other hand, while there only five roads named 'Street' in Crawley, there are lots of streets named 'Road'. It does appear that the Crawley town planners had a real dislike for 'Street'.

If you want more proof of my theory that we don't call roads 'Street' any more then you can explore the distribution of streets and roads in some of the UK's medieval cities in Medieval Streets and Modern Roads. In this post I looked at how roads named 'Street' tend to be found in the old city centers. These centers also contain very few roads. However city suburbs, mostly built after 1800, have lots of streets named 'Road' and very few named 'Street'.

Obviously the name of my interactive map is a misnomer and it should be called 'There Are Five Streets in Crawley'. However it is true that There Are No Roads in London.

Thursday, November 14, 2019

Cattle & Deforestation in the Amazon

The large number of fires in the Amazon this summer were closely linked to an increase in deforestation. Most of the areas which have recorded the largest number of fires in 2019 have also had the largest number of deforestation warnings. One of the most common causes of deforestation in the Amazon is the increase in cattle farming.

InfoAmazonia and China Dialogue have created an interactive map to visualize the expansion of cattle in the Amazon biome. The interactive map in Rising Beef Demand Linked to Amazon Deforestation colors municipalities by the number of cattle. If you hover over a municipality on the map you can view a graph showing the rise or fall of cattle farming in the region over time. The map also shows the locations of slaughterhouses in the biome.

The China Dialogue article accompanying the map explores the growing consumption of beef in China. This growing demand for beef in China is responsible for much of the expansion in cattle farming in the Amazon region. Exports of beef to China account for 38.2% of Brazilian sales of packed meat. In comparison the USA accounts for 2.7% of Brazilian exports of packed meat

UK Rain, River Levels and Snow

This week a number of locations in the UK have experienced severe flooding. The UK Environment Agency has warned that with heavy rain forecast in some areas over the next four days that further flooding is expected, particularly in South Yorkshire. People in Lincolnshire and the Midlands should also remain aware that flooding may be a risk over the next few days.

The UK government's Flood Warnings for England map shows the locations in England where flood warnings are currently in operation. If you click through on a flood warning's marker on the map you can read more on local river levels and high tides. You can also read about the forecast flood risk and the latest advice to people living in the effected area. If you zoom in on the Flood Warnings for England map you can also view colored polygons showing the areas where flood warnings and flood alerts currently apply.

If you live near a river then as well as referring to the government's Flood Warnings map you might also want to check out this interactive map of river level monitoring stations. River Levels UK maps river gauges using colored arrows. The direction of the arrows show whether the river levels are currently rising or falling. The red arrows indicate that the current level is higher than normal for that location, while green arrows indicate river levels lower than normal. If you click through on a gauge's link you can view more details, such as the time of the latest river level reading.

The government's own River and Sea Levels map also shows the latest measurements from river level monitoring stations. On this map the monitoring stations are colored to show gauges where flooding is possible and where flooding isn't currently a concern. If you click through on a gauge's link on the map you can view a chart of the gauge's measurements over the last five days. This chart includes a line which shows the levels at which flooding becomes possible at that location.

While many areas of the UK experienced heavy rain overnight, some areas have also seen their first snow of the winter. The #uksnow Map uses crowdsourced Tweets to map the location and levels of snow. According the the #uksnow Map snow has fallen in a narrow band from Oxford to Bristol.

Wednesday, November 13, 2019

Online GeoJSON Editors

I use nearly everyday to create and edit GeoJSON data. I find it particularly useful for tidying up and minimizing third-party data which I have downloaded from elsewhere. For example, I find very useful for previewing data which I've exported from overpass turbo. Once I've loaded the data into I can then remove or add data depending on my mapping needs.

Vector GeoJSON is another GeoJSON editor which has just been released. Like the online editor can be used to create or edit GeoJSON data directly from your browser. Using Vector GeoJSON you can import data which you have saved from elsewhere. Alternatively you can create data from scratch by adding points or polygons to the Vector GeoJSON map. When you have finished creating or editing your spatial data you can save it as a GeoJSON file. Vector GeoJSON also has an option to covert your GeoJSON to a shapefile (via the ogr2ogr web client).

Perhaps not surprisingly (because Vector GeoJSON has only just been released) at the moment has more options. I particularly like's table view, which makes it very easy to delete surplus features in your data. also currently has more options for exporting your data. As well as saving your finished data as a GeoJSON file allows you to save your spatial data as a shapefile, topoJSON, CSV or KML. 

Tracking Tropical Storm Fengshen

Typhoon Tracking is an interactive map which shows the projected path of tropical storm Fengshen. The map combines an overlay of the storm's predicted path with a movie of how the storm appears from the Himawari-9 satellite. The predicted path was downloaded from the Joint Typhoon Warning Center. The video of the storm was created using images from the Himawari-8 Real-time Web website.

I created this map to meet Day 13's 'tracking' map task in the #30DayMapChallenge I really don't like the map very much but it has taken me far too long creating this already and I haven't got any more time to spare today to improve the map. One big mistake I made in making the map was to add the storm's track to a map style in Mapbox Studio. This means that the track is part of the base-map and appears below the video layer. If I had some more time I would add the storm's track as a layer above the video layer, so that the track isn't hidden behind the video.

If I had a lot more time I might also play around with the color values in the satellite images so that the created animated video blends more seamlessly with the sea color in the background Mapbox satellite map layer.

If you want to create your own video overlay map using Mapbox GL then you should have a look at this video overlay demo map from the Mapbox GL documentation.

Tuesday, November 12, 2019

Australian Bushfire Maps

Many parts of Australia, in particular in New South Wales, are experiencing record levels of bushfires. One fire on its own in Coffs Harbour, NSW has a perimeter of 1000 kilometres. With no rainfall forecast and the promise of warm dry conditions for the coming week the extreme threat of fire in the state is expected to continue.

MyFireWatch is an interactive map providing information on the locations of the latest bushfires in Australia. The map uses data from remote sensing satellites and is updated every 2-4 hours, depending on the position of satellites. If you select a fire marker on the map you can read details on the time and date when the fire was last detected and its longitude and latitude.

The NSW Rural Fire Service also provides an interactive map of fires in New South Wales. The NSW Rural Fire Service map shows the locations of fires and the latest known fire extents. The map uses markers which are colored to show the current alert level for the mapped fire. Red markers show the location of fires with an emergency warning alert level. Major fire updates are also listed under the map.

The animated GIF at the top of the page uses images from the Himawari-8 satellite. You can explore satellite imagery of Australia yourself on the Himawari-8 Real-time Web viewer. The times on the GIF are I presume shown in my local time. Sydney is 11 hours ahead so these images are from yesterday afternoon in New South Wales.

If you want to create your own animated GIFs from satellite imagery then another good source of imagery is the RAMMB/CIRA Slider website. This tool allows you to create animated GIFs from satellite imagery from GOES-16 and Himawari-8. The slider uses the latest available imagery from both satellites to allow you to create small animated movies of the Earth.

Mapping the Global Land Grab

Large-scale land acquisitions (LSLAs) can have a devastating impact on local communities. Across the world, particularly in the developing world, land which is used by smallholders and local communities is being bought up by large corporations for agricultural production, for the extraction of natural resources or for industrial development. These controversial land transfer deals often take place behind closed doors and with very little transparency.

The Land Matrix Initiative was established in 2009 in order to gather data on LSLAs and to help promote transparency and accountability in how LSLAs are carried out across the world. The Land Matrix website provides open access to this data, providing information on attempts to acquire land in low- and middle-income countries around the globe.

The Land Matrix interactive map plots the locations of LSLAs in countries across the world. The markers on this map are colored by default to show the implementation status of all the deals represented. You can also select to display the intention of the land deals represented by the markers (agricultural, mining, industrial etc). The Land Matrix data can also be explored using a searchable database and in an interactive graph.

If you are interested in the issue of land ownership then you might also be interested in Who Owns America and Who Owns England.

Monday, November 11, 2019

L.A.'s Wealth Mountains

The Topography of Wealth in L.A. - Visualizing Income Inequality as Terrain is an impressive story map which explores the city's vast income disparities using elevation as a metaphor for wealth. As you scroll through the story the map highlights areas of the city where there is a huge disparity between the median incomes of people living in adjacent neighborhoods.

On the Topography of Wealth map areas of Los Angeles are shown at different heights depending on the area's median annual household income. Neighborhoods with a high median annual household income are shown as tall towers while neighborhoods with a low median income are shown as smaller towers.

The map provides a striking visualization of the distribution of household incomes in the city. Many places in the city have neighborhoods with extremely high median incomes right next door to neighborhoods with very low median incomes.

The map was made with QGIS, Blender, GSAP and D3.js.

Spanish Election Maps

El Diario has mapped out the results of yesterday's Spanish election. Today's election was the second this year and the fourth in as many years. The Spanish Socialist Workers’ party (PSOE) won the most seats in Sunday's election. However their 120 seats was three fewer than they won in April and so the party still has no majority. The extreme far-right Vox party jumped into third place while the centre-right Citizens party saw a collapse in their vote.

El Diario's interactive map of yesterday's results shows the winning candidate in each seat. You can also switch the map so that it visualizes the second most popular party in each seat or the third most popular party in each seat. The map also includes a view which allows you to see only those seats which have changed hands since April's election and which parties won those changing seats.

El Diario has also created an arrow swing map which visualizes how votes have swung in each electoral seat since April's election. On this map blue and red arrows are used to show the size of the swing to the left or right since April (note for U.S. readers in most of the world red is used for left wing parties and blue for right wing parties).

The arrow swing vote shows that although PSOE won the most votes nationwide there was a rightward swing in huge areas of Spain. Only really the provinces of Cantabria, Teruel, Madrid and Balears saw significant numbers of seats with a leftward swing in yesterday's election. This was nowhere near enough to win the PSOE a working majority.

Because PSOE failed to win a majority I would't bet against Spain having at least one other election next year (to make it five elections in five years). However turnout in this election was significantly down on the April election. The turnout in April was 75.5% and yesterday the turnout was 69.9%. This suggest that Spanish voters may be beginning to experience election fatigue.

Sunday, November 10, 2019

New York in Black & White

Challenge number 10 in the #30DayMapChallenge is to create a black and white map. My attempt to meet this challenge is New York in 3D, an interactive map with 3D extruded buildings.

I created the 3D extruded building map style using Mapbox Studio. If you want to know how to do this the Add 3D buildings to a Mapbox Studio style tutorial is a great step-by-step guide to extruding buildings (or any other layer which includes polygons). Once I had created the style in Mapbox Studio I then simply added it to Mapbox's Fly to a location example map. This map adds a button to the map which when pressed rotates and pans the map to a different location. This provides the user with a very short aerial tour of Manhattan.

My map isn't very impressive. However, if you are a fan of monochrome maps, I recommend you check out the winners of the 2019 Monochrome Mapping Competition. The results of this competition have lots of beautiful black & white maps (and other types of monochrome map).

Saturday, November 09, 2019

The Australian Bushfires From Space

Earlier today I linked to a satellite video map showing the ever changing appearance of the Yellow River Delta. That map uses satellite imagery from NASA with Mapbox GL's video overlay functionality.

If you want to create your own timelapse videos from satellite imagery then NASA is obviously a great source for your imagery. Another good source is the RAMMB/CIRA Slider website. This tool allows you to create animated GIF's from satellite imagery from GOES-16 and Himawari-8. The slider uses the latest available imagery from both satellites to allow you to create small animated movies of the Earth.

GOES-16 is in geostationary orbit over the Earth’s Western Hemisphere. It therefore provides great satellite imagery of the Americas. Himawari-8 is in geostationary orbit at 140.7 degrees East. It provides near real-time imagery of Australia, Japan and eastern China.

Currently a record number of bushfires are burning in the state of New South Wales in Australia. Smoke from these fires can clearly been seen in imagery captured by the Himawari-8 satellite. My Australian Bushfires map uses a video loop of Himawari-8 satellite imagery captured yesterday afternoon overlaid on the eastern coast of Australia.

China's Yellow River Delta

My Yellow River Delta map shows the ever changing appearance of the mouth of the Huang He (Yellow River) in China. Millions of tons of sediment enters the river every year. Much of this sediment is carried as far as the river's mouth where it continually rebuilds the delta.

On the Yellow River Delta map a video overlay loops through a series of satellite images. These natural-color images, from NASA's Landsat satellites, show the delta at five-year intervals from 1989 to 2009. To create my map I turned the images into an mp4 video. I then simply added my video URL into Mapox GL's example Add a Video demo.

Friday, November 08, 2019

The Australian Music Map

The Australian Broadcasting Channels' The Australian Music Map, is an interactive map which allows you to explore and listen to classical music written by Australian composers. The map includes music by composers who are strongly linked to a particluar location and music which has been composed especially for a specific Australian place.

If you select a marker on the Australian Music Map you can listen to the featured track directly from the map. An information window will also open featuring information on the selected composer, the classical music track and its connection with the mapped location.

The connection between sound and place in Australia is nothing new. In fact it dates back as far as the earliest arrival of homo sapiens. Long before maps and compasses were invented the indigenous people of Australia used songlines to navigate the country and find their way around.

Songlines, or dreaming tracks, are the creation myths of Indigenous Australians. They are the paths that the creator-beings took across the world while naming and creating the features of the land. These songlines crisscross Australia and, if you know the songline, you can follow the routes that the creator-beings took across the country.

By singing the songlines indigenous people can navigate vast distances, often travelling through the deserts of Australia's interior. You can learn more about songlines from different parts of Australia with this story map from ABC. Singing the Country into Life explores the songlines of a number of indigenous groups across the whole country.

The ABC storymap helps explain the importance of songlines to aboriginal culture. They tell not only how the land was created but also provide a guide as to how you can navigate that land. Since the destruction of much of the original indigenous way of life they now also provide a valuable connection to threatened indigenous languages and culture.

Central Park in Green

Day 8 of the #30DayMapChallenge is colored a rather fetching shade of green. For my green map I decided to take a little inspiration from abstract art.

My Kandinsky Park map is a homage to the Russian painter Wassily Wassilyevich Kandinsky. On this map different OSM id numbers have been given a different shade of green and all polygons have been rotated slightly. If you squint your eyes a little the resulting map can at time slightly resemble the artwork of Kandinsky.

There is absolutely no point to this map. The level of abstraction in the geographical data makes it a little hard to use as a map. I do like to think however that my map conforms, at least in part, to Al Capp's definition of abstract art as being "a product of the untalented sold by the unprincipled to the utterly bewildered".


Thursday, November 07, 2019

Mapping Journalist Deaths

In just the last 12 years over 1000 journalists have been killed around the world. KeepTruthAlive is an interactive map which has been created by UNESCO to show where journalists have been killed around the world. The map was created for the UNESCO campaign #KeepTruthAlive.

The interactive map uses data from UNESCO and only shows journalists who have been killed from June 1993 until July 2019. The locations on the map do not show an exact address and are mapped at the city level. 9 out of every 10 of the murders shown on the map remain unresolved and the killers have not been brought to justice.

The Committee to Protect Journalists (CPJ) maintains a database of attacks of journalists and the press around the globe. 76 journalists across the world were killed in 2018. The CPJ database includes journalists who were murdered in the last 12 months and also journalists who were killed in action (from crossfire or combat on assignment).

Afghanistan, Mexico and Syria, respectively, were the three countries where the most journalists were killed in 2018. The CPJ's 2018 Map of Journalism Deaths includes four motive confirmed murders of journalists in the United States in the last year. All four of these deaths were from the attack on the Capital Gazette. On June 28th Jarrod Ramos shot and killed five employees of the Gazette in Annapolis, Maryland. Four of the victims were journalists working for the newspaper, the other victim was a sales assistant.

The CPJ map includes a number of filters which allow you to explore the database of journalist deaths by location and type of death. The map also includes a date filter which allows you to directly compare the year's map of journalist deaths with maps for previous years (going back to 1992).

Red Towns & Cities of the World

Day 7 of the #30DayMapChallenge brings us to the color red. In honor of the occasion here is an interactive map of all the red towns and cities around of world.

My map isn't very interesting at all. However it is a neat example of the power of importing and styling your own data in Mapbox Studio. The ability to add and style your own place labels in Mapbox Studio has been used particularly effectively this year in The Pudding's A People Map of the USA.

To get the data for my map I ran a search in Overpass Turbo for towns and cities including the letters 'red' (I also searched for 'rouge' and 'rot'). I then downloaded the results as a GeoJSON file. I uploaded this GeoJSON data to Mapbox Studio to create a data tileset. I then added this tileset to a new Mapbox map style. In my Mapbox style I turned off all the other place-name labels and styled my new tileset so that my new place-name labels are all colored red.

Earlier this year I used the same Mapbox Studio functionality to create the Map of English Literature, an interactive map which shows the birthplaces of some of English Literature's greatest writers. On this map authors, poets and dramatists have been mapped to their place of birth (although there are a few exceptions where writers have been mapped to locations which they are more commonly associated with).

Wednesday, November 06, 2019

Mapbox's New Scrollytelling Template

Story Maps are an excellent way to not only visualize geographical data but to pick out the stories and patterns in your mapped data. Thanks to Mapbox's new Scrollytelling Template there is now a new tool to help you create your very own 'scrollytelling' map stories.

You can preview a story map created with the Scrollytelling Template on this demo map. The demo map not only introduces the new Scrollytelling Template it shows you what you can do with the template. As you scroll through the story the map zooms and pans to different locations. It also adds and removes data from the map and adds and removes different map layers and features as you scroll up and down on the page.

I've only had a quick look at using the template myself. Creating your own story map, mainly by adding your own text and locations to the config.js JavaScript file, is reasonably straightforward. It also seems fairly straightforward to add your own layers to a 'chapter' when you want to change the data or appearance of the map. However creating a story map with the Scrollytelling Template isn't a trivial task.

I'm still a big fan of Mapbox's Scroll Driven Navigation map in the Mapbox GL example maps. If you just need a simple story map template then I think I would use the Scroll Driven Navigation example. The new Scrollytelling Template comes into its own however when you need to add and remove map features and layers for each chapter in your story and if you want to add and remove different data layers.

From the example scrollytelling maps provided on its GitHub page it appears that the Scrollytelling Template disables any user reactions with the map by default. Looking through the configuration options there doesn't appear to be any easy way to allow users to interact with the actual map. Therefore it looks like you will have to play around with the CSS styles which hold the story text if you want your users to be able to explore and play with the underlying map.

Mapping the Dutch Slave Trade

The Dutch Trade in Black People is a story map exploring the role of the Netherlands in the transatlantic slave trade. The story uses an interactive map to explain the triangular trade between the Netherlands, West Africa and the New World. The map is also accompanied by and illustrated with a number of contemporary paintings depicting enslaved Africans, the slave ships used by the Dutch and the slave plantations in the New World where enslaved Africans were forced to live and work.

The Dutch, and in particular the Dutch West India Company (WIC), played a large role in the slave trade. Between the 15th and 19th centuries around 12 million Africans were enslaved by Europeans. The Dutch were responsible for around 6% of that slave trade. During certain periods the expanse of the Dutch West India Company allowed the Dutch to play a far larger role in the slave trade. For example between 1650 and 1675 half of all the slaves transported between Africa and the new world were shipped by the Dutch.

As you progress through the Dutch Trade in Black People story map the interactive map is used to highlight locations important to the Transatlantic slave trade. For example it is used to show the west coast of Africa where the Europeans built forts and where enslaved Africans were housed before being transported to the New World. The map is also used to show some of the locations in the New World which played a significant role in the slave trade. For example, the island of CuraƧao, which became an important station for Dutch slavers.

The triangular slave trade played a major role in the Dutch economy for over two centuries. Ships from the Netherlands traveled to West Africa with weapons, ammunition, liquor and textiles. With this merchandise the slavers bought enslaved Africans. The ships then transported these slaves to the new world where the slaves were then sold. The slave ships were then packed with sugar, coffee, cotton, cocoa or tobacco from the plantations and then returned to the Netherlands.

You can get a better understanding of this huge triangular slave trade network between Europe, Africa and the New World by exploring Slave Voyages. The Slave Voyages website maintains databases of the Trans-Atlantic and Intra-American slave trade. These databases include information on 36,000 slave trading voyages from Africa to the New World carried out between 1514 and 1866; 11,000 voyages from one part of America to another; and personal details about 91,491 Africans who were forced into the slave trade.

Slave Voyages provides an introduction to the Trans-Atlantic slave trade using a series of static maps. These maps are from the Atlas of the Transatlantic Slave Trade and help to illustrate the trade routes used to transport slaves, the countries involved in organizing the trade and the volume of people traded. A Timelapse animated map also plots 14,289 slave voyages crossing the Atlantic over time. This map shows the actual journeys of slave ships from Africa to the Americas by year. It provides a sharp illustration of the sheer scale of the slave trade.

This isn't the only mapped visualization of the Transatlantic Slave Trade Database. In 2015 Slate released the Atlantic Slave Trade in Two Minutes, a map which also animates the journeys of slave ship journeys over a period of 315 years. Slate's map reveals the patterns of the trade routes used and the destinations of the slave ships. The size of the ships on the map are scaled to represent the number of slaves on board. You can also click on each ship to find out under which country's flag a ship sailed.

Tuesday, November 05, 2019

Mapping the Epistles of Paul

You can now read and explore the world's oldest existing manuscript of the letters of St. Paul as an interactive map. The University of Michigan's Epistles of Paul presents the original manuscript of the letters of St.Paul as an interactive Leaflet map, shown side-by-side with a modern translation of the text.

If you click on the text icon in the map menu then all the lines in the original manuscript are made interactive. Now if you mouse-over a line on the manuscript the corresponding line is highlighted in the translation. The translated text also includes interactive footnotes. These footnotes mostly explore some of the differences in the historical manuscript from the standard text of the New Testament.

The thirty leaves of the manuscript held by the University of Michigan were written in about 200 C.E. and were found in Egypt in the 1930's. The Epistles are written in ancient Greek. The original manuscript was written without word division, punctuation, headings, or chapter and verse numbers. So even if your ancient Greek is very good you still might need the help of the modern translation.

The Epistles of Paul viewer was made using Jack Reed's Leaflet-IIIF, which is JavaScript library for viewing IIIF images with a Leaflet.js interactive map. IIIF is a format which is used by museums, newspapers and galleries around the world for presenting and sharing digitized images. A IIIF viewer is a tool for presenting artworks and digitized records in a form like an interactive map. A IIIF viewer essentially allows you to pan around and zoom in and out on a digitized image like you would on an interactive map.

Many museums and libraries around the world have created IIIF manifests for their collections of vintage maps. The Leaflet-IIIF Leaflet plug-in is therefore a fantastic resource for presenting and exploring vintage maps from many of the world's largest map collections. In the Epistles of Paul the plug-in has been used to present an interactive interface for reading an original historical manuscript. The plug-in can obviously be also used as an interface for exploring vintage maps which have been made available as IIIF manifests.

For example my Matthew Paris' Map of Britain uses the Leaflet-IIIF plug-in to present a short story-map of Matthew Paris' Map of Britain. Matthew Paris' Map of Britain is one of the first ever geographical maps of Britain. It was made by Matthew Paris, a 13th Century monk.

My story-map examines some of the geographical errors Matthew Paris' made in his map of Britain in order to better understand the geographical conception he had of Britain in the 13th Century. The map also includes modern English translations of medieval place-names. Just click on the place-names on the map to view the names we now use for these towns and cities.

My map uses the IIIF manifest of Corpus Christi College's manuscript of Matthew Paris' map. As well as using Jack Reed's Leaflet-IIIF plug-in the story-map element makes heavy use of waypoints.js to trigger the map actions when scrolling the page.

Raster Rivers & Railways

Most of the major interactive map providers, such as Google Maps and Bing Maps, are vector maps. However they didn't begin as vector maps. Both Google Maps and Bing Maps began life as raster maps.

A raster map is a map which is made from lots of static map images. An interactive raster map is essentially a tiled grid of lots of different images, each containing a different part of the map. When you zoom in on an interactive raster map new more detailed map images are loaded into the map.

On the other hand, in very simple terms, a vector map uses map data rather than static images. Map features such as building footprints, roads, rivers, elevation etc. are all served as different types of data. A vector map is basically a database of points, lines and polygons. Other types of information can be assigned to this data, such as the height or the age of a building. This makes vector maps very useful for analyzing and visualizing geographical data.

Today's #30DayMapChallenge is to create a raster map. Lyzi Diamond of Glitch has created a raster map of Global Rail Lines. The map was made for day two of the challenge, which was to make a map with lines. However the Global Rail Lines map is also a great example of a raster map. The map uses data from Natural Earth to show only the world's railways.

I followed the same process as Lyzi took to create my own raster map. My World Rivers map is an interactive raster map which shows only the world's rivers and no other geographical features. Like Lyzi I got my 10m railway data from Natural Earth. I also updated the data into Mapbox Studio to create a map style and then used the Mapbox Static Tiles API to serve the raster map tiles to my Leaflet.js powered interactive map.

Monday, November 04, 2019

The Global Threat of Rising Seas

The threat of rising sea levels now affects millions more people than previously thought. A new elevation model from Climate Central reveals that many of the world’s coastlines are far lower than had previously been believed. The result is that rising seas are likely to affect many more areas than in previous models of climate change.

Climate Central's Coastal Risk Screening Tool is an interactive map which shows the risk around the world of rising seas in 2050. The map shows all land across the globe which is predicted to be below annual flood levels in 2050. The map includes two predefined climate change models - a model which uses a mid-range of global heating and a model which predicts a higher level of global heating. The map also includes a control which allow you to view predictions of sea level rise for other years.

At the bottom of the map sidebar you will find controls which allow you to switch between Climate Central's new elevation model and a legacy elevation model. This allows you to see how the new elevation model differs from previous projections of sea level rise.

Manhattan Bars Hexbin

This interactive hexbin map of Bars in Manhattan shows the hottest nightspots in New York (not really). The map is my latest map in the 30 Day Map Challenge. Hexbins are the subject of day 4 of the #30DayMapChallenge.

The Bars in Mahattan map uses turf.js to create a hexbin map visualizing the number of bars across Manhattan. On the map each hexagon is colored to show the number of bars in that hexagon. The data for the map comes from an Overpass Turbo query of OpenStreetMap data. I really can't take any credit for the code as my map is a simple clone of Dan Swick's map of Chicago rat sightings - Ratmap.

Regular readers of this blog may remember that I recently used the same Manhattan bars data to map out the number of bars by Manhattan neighborhood. Manhattan Bars colors New York neighborhoods by the number of bars which they contain. The bars on this map are shown with small black dots. You can click on these dots to view a bar's name.

The hexbin map does help to reveal the problems of mapping bars by neighborhoods of different sizes. The choropleth layer on the Manhattan Bars map fails to pick up the cluster of bars east of the Guggenheim Museum. However on the hexbin map this area does show up as a bright red hexagon - revealing more clearly the cluster of bars in the area.

Sunday, November 03, 2019

The Orientation of London's Churches

Today's #30DayMapChallenge is to create a map containing polygons. My Church Orientations map displays London churches as extruded polygons. The compass rose on the map also visualizes the orientation of all the churches in the current map view.

Since the 8th Century churches have tended to be built facing towards the east. The main focus of a church, the alter, is placed at the east end of the church, often in an apse. The major entrance to the church is often placed at the west end. In fact the word 'orientation' actually comes from the practice of constructing buildings to face the east. Building a church the other way around, with the entrance at the east and the apse at the western end, is called 'occidentation'.

nine English cathedrals - mainly oriented to the east (looking at you Liverpool Cathedral)

When early Christians prayed they would face towards the east. Hence the tradition of building churches with the alter towards the east. One theory for why Christians pray towards the east is that the beginnings of the organized church was in Europe and worshipers were praying in the direction of Jerusalem. Another theory for why churches face east is because they have been aligned to where the sun rises on each church's saint day.

My Church Orientations map uses the building footprints (the lines which define the outline of the churches) for the orientation compass rose. In other words the compass rose shows the orientation of all the churches' walls (in the current map view). In general the map reveals that churches in London are roughly orientated eastwards, with a fair share orientated between east and north-east.

Saturday, November 02, 2019

Miami Street Orientation

In many American cities the street grid system is often reflected in the names of the city's streets. For example in some cities you might find that all roads called 'Avenue' run north to south, while all roads called 'Street' run west to east (or vice versa depending on the city).

It is possible to visualize this pattern very effectively with an interactive map and a radial chart. My Miami Streets map visualizes the directions of all roads called 'avenue' and 'street' in Miami. On the map all roads named 'Avenue' are colored red and all roads named 'Street' are colored blue. Simply by looking at the map you can tell that streets and avenues run in distinctly different directions in Miami. The radial chart on top of the map visualizes this more explicitly, showing the overall orientation of all the streets and avenues in the current map view (move the map around and the radial chart will update to show the orientation of all streets and avenues in the current map view).

By exploring the map you can see 'streets' in Miami run almost exclusively west to east while 'avenues' run north to south.

All the code for my map comes from Vladimir Agafonkin's fantastic Road Orientation Map. Vladimir's map visualizes the orientations of all roads in the current map view. The map can be used to explore the orientations of roads anywhere in the world. For my map I tweaked the code to only show the orientations of roads named 'avenue' and 'street' and to ignore all the roads called 'lane', 'avenue', alley' etc.

The original Road Orientation map fetches all the roads in the current map view with a single line of code:

var features = map.queryRenderedFeatures({layers: ['road']});
In effect it queries the layer named road in a Mapbox map. This means we can simply change the layer name to fetch different data. For example we can easily change the query to fetch the layer which displays waterways:

var features = map.queryRenderedFeatures({layers: ['waterway']});
Simply by changing 'road' to 'waterway' we can alter the map to display the orientations of all rivers and canals rather than the orientations of roads.

The original Road Orientations Map will work with any map layer in which the mapped feature is of the type 'line' (so map data which is in the form of polylines). Therefore to create my map I only needed to upload two GeoJSON files to a Mapbox style:- one GeoJSON file with the data of all 'avenues' in Miami and one GeoJSON file with the data of all 'streets' in Miami.

In Mapbox Studio I named these two layers 'avenues' and 'streets'. All I needed to do then was change the JavaScript to query my two layers rather than the 'road' layer:

var features = map.queryRenderedFeatures({layers: ['avenues', 'streets']});

Miami is not the only American city which helps you orient its grid system by having its avenues and streets running in different directions. New York also uses this form of street planning. You can see this on my Street Orientations map, which visualizes the directions of all roads called 'avenue' and 'street' in Manhattan.

Friday, November 01, 2019

How to Find Your Nearest Mountain

Topi Tjukqnov has set a 30 Day Map Challenge. The challenge is to make a different map every day during November. To help inspire cartographers Topi has also published a list of 30 different themes and functionality that your maps could include on each day.

November 1st's suggestion is 'points'.

Inspired by Closest Volcano I decided that for the first day of the #30DayMapChallenge I would create a Nearest Mountain interactive map. If you enter an address into the Nearest Mountain map then the closest mountain will be highlighted on the map. The map sidebar will list all the other peaks in the U.S. in order of distance from your address. The map also informs you how many miles away each mountain is from your address.

The data for my map comes from Open Peaks, an opensource list of mountains around the world which is available as a series of GeoJSON files. I only used the GeoJSON file for the United States (which doesn't include Hawaii for some reason). This means that my map will only work for addresses in the contiguous USA.

To create my map I simple cloned the final map in Mapbox's Build a Store Locator tutorial. I then simply switched out the GeoJSON file of stores in the original for my Open Peaks GeoJSON file of mountains in the USA.

If you want to see what everybody else has created today for the #30DayMapChallenge just have a look at the hashtag on Twitter.

Thursday, October 31, 2019

Mapping Global Wind Power Potential

Despite growing by 30% in the last nine years offshore wind power still only provides 0.3% of electricity around the globe. Some countries, such as the UK, Germany and Denmark have recently added a lot of offshore wind power capacity. However there is still huge potential for offshore wind power around the world. In fact wind power has the potential to provide more than 18 times the global electricity demand today.

The IEA in collaboration with Imperial College London has assessed the potential for offshore wind development across the world. Alongside its report into the potential of wind power IEA has created an interactive map which shows where offshore wind has the highest technical potential and where the latest offshore wind projects are being built. The map in Offshore Wind Outlook 2019 uses four colors to show the areas of highest potential. These colors show areas in deep & shallow water and in regions far & near from shore.

The potential for offshore wind power generation is modeled using a number of variables, including wind speed and weather data from global reanalysis models.

Mapping Cancer Alley

The land along the Mississippi River between Baton Rouge and New Orleans is often referred to as 'Cancer Alley'. The area is dominated by chemical plants and is consequently one of the most polluted places in the USA. ProPublica has used Environmental Protection Agency scientific model to map out the concentrations of toxic chemicals between Baton Rouge and New Orleans.

In a Notoriously Polluted Area of the Country, Massive New Chemical Plants Are Still Moving in uses a story map to show the location of chemical plants in the area and the pollution that they are causing. As you progress through the story the map shows the air toxicity levels from cancer-causing chemicals based on the EPA scientific model. The story map also reveals where Louisiana has granted permits for new chemical plants to be built and what their impact will be on the pollution levels in the neighborhoods where they are built.

ProPublica has also looked at where these highly polluting chemical companies are being allowed to be built. It found that Louisiana are refusing permits in areas which have a predominantly white population but are allowing their construction in predominantly black populated districts. Some conurbations in Cancer Alley have city status and are able to refuse planning for new chemical plants. However they can't stop the pollution from nearby plants.

At the end of the ProPublica story you can enter any address in the region to show a map visualizing the local air toxicity levels.

The First 2019 UK Election Map

The UK has set a date for a new national election. The election on December 12th is by default almost becoming a second referendum on Brexit. It will also result in many, many new election maps. The first of which is Maproom's 2019 UK Election Map.

This interactive map colours each electoral constituency by the political party of the currently sitting MP. If you click on a constituency you can view the size of the electorate, the size of the sitting MP's majority and the percentage who voted for Leave or Remain in the 2016 EU Referendum Result. You can also click-through to research the MP's voting record on TheyWorkForYou.

The map is reasonably useful as it stands but I wish it had a few more options. For example, as the map already has the data on the 2016 EU Referendum it would be useful if the map included the option to view constituencies by their support for Brexit. This would help users identify Conservative MP's in remain supporting areas and opposition MP's in leave areas. It would also be useful to have a choropleth layer which allowed you to explore the size of each MP's majority. This would allow users to identify the most marginal seats, these will  be the seats which are likely to decide the outcome of the next government and whether the UK leaves the EU or not.

Wednesday, October 30, 2019

How Flanders Has Changed in 50 Years

The Flanders region of Belgium has changed a lot in the last 50 years. If you want to know how the area has changed then you can explore the 50 Years of Concreting in Flanders interactive map.

50 Years of Concreting in Flanders uses aerial photography from 1971 to show how the region looked from the air half a century ago. Using the map you can search for any address and compare modern aerial imagery with the historical aerial imagery to explore how the area has changed. The 1971 imagery has a spatial resolution of 1 meter, which means that it is of a high enough resolution to be able to identify individual houses.

The map was made by Maarten Lambrechts, who has also written an interesting blog post on how the map was made. In A look through history map of Flanders - the making of Maarten explains how he made the historical imagery into a map tile layer which could be viewed using an interactive map. He also explains how he developed the functionality to share a location on the map. This allows users to simply cut & paste the URL of a location on the map which they can then share with friends or family.

Tuesday, October 29, 2019

How to Find a Halloween Costume

If you haven't planned what you are wearing for Halloween this year then you need This is Halloween. Every year two major pop-up costume retailers, Spirit Halloween and Halloween City open stores across the country. Because the two companies take advantage of otherwise empty stores their locations usually change year-on-year. This can make them a little hard to find.

That is why Jonah Adkins decided to make his handy This is Halloween store locator. Using the interactive map you can search for an address or zoom in on a city to view all the nearby Spirit Halloween and Halloween City stores. The stores are shown on the map using colored ghost markers (pink for Spirit Halloween and blue for Halloween City). If you click on a marker you can view the store's address and web link.

If you have already chosen your Halloween outfit for this year then you might be more interested in reading about how the map was made. In This is Halloween - It all started with a map Jonah provides detailed information about how he made the map. This how-to guide includes details on using All the Places to scrape the data and create a custom made API. Jonah's guide also includes information about how Tangram was used to style the map into a suitable ghostly theme.

How to Find Your Nearest Volcano

If there is an emergency do you know how to find your closest volcano? I like to think of myself as a keen amateur volcanologist, but even I have to admit that there are times when I am unaware of where to find my nearest volcano. Especially when I am traveling somewhere new, either for work or for pleasure.

That is why I always carry Closest Volcano.

Closest Volcano is an essential interactive map for finding your nearest volcano, wherever you are in the world. If you share your location with Closest Volcano it will show you the location of your nearest volcano on an interactive Google Map. It will also tell you the name of the volcano, its elevation and what type of volcano it is.

My nearest volcano is the Chaine des Puys in France. Luckily for me it is a Dome volcano.