Friday, May 27, 2022

America's Mass Shooting Problem

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

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

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

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

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

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

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

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

Thursday, May 26, 2022

Polluting the Poor in San Francisco


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

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

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

Tuesday, May 24, 2022

Australian Election Maps

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


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

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

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

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

Sydney before and after the 2022 election

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

 

Perth before and after the 2022 election

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

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

Downloading Microsoft's Building Footprints

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

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

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

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

Friday, May 20, 2022

How Election Maps Lie

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

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

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

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

Thursday, May 19, 2022

The Deadly Streets of San Francisco

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

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

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

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

Wednesday, May 18, 2022

Street View of War

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

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

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

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

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

Tuesday, May 17, 2022

Mapping Fire & Flood Risk

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

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

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

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

Monday, May 16, 2022

Geo Sentences

My life is about to get a lot easier.

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

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

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

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

Sunday, May 15, 2022

A Super Blood Moon Lunar Eclipse

Tonight, beginning at around 10.30pm (EDT), you will be able to watch a full lunar eclipse. On May 15th the sun, moon and Earth will align. Between 10.30pm and 2am the Earth will move between the sun and the full moon and as a result the Earth's shadow will pass across the surface of the moon. As the Earth's shadow passes over the moon it will cause the moon to have a reddish hue. This is why a lunar eclipse is also called a blood moon. At the moment the moon is at its closest point to Earth in its orbit. Therefore the moon appears in the night sky at its biggest and brightest. This is known as a supermoon. 

The lunar eclipse will be visible in the USA on Sunday evening and before dawn Monday morning in most of Europe (in London the partial eclipse will start at 3.27am). You can find out when you can view the lunar eclipse at your location on Time and Date. Enter a location into Time and Date and you can view an animation of the full lunar eclipse, revealing the times when the penumbral, partial and full eclipses start and when the full, partial and penumbral eclipses end.Time and Date also shows you the time of the maximum eclipse at your location. 

Time and Date has provided information on the direction and altitude of the moon in the night sky. In the USA, if the sky is clear and free of clouds, you shouldn't have too much trouble viewing the eclipse. In you live in the UK, because of the moon's very low position in the sky, your best chance of seeing the eclipse will be from a high altitude such as a tall building or from the top of a hill.

Friday, May 13, 2022

Mapping Rising Seas

NZ SeaRise is an interactive map which reveals how rising sea levels might effect locations around the coast of Aotearoa based on different climate change scenarios. Using the map you can view the likely impact of sea level rises at 7,434 sites around New Zealand (covering every 2km of coastline).

Because New Zealand suffers from a lot of techtonic activity mapping the impact of sea level rises in the country also involves calculating where coasts are moving up (uplift) and down (subsidence) in relation to sea level. NZ SeaRise includes data on the likely rate and direction of vertical land movement for every 2 km of Aotearoa's coast. 

The colored dots on the map show the projections of vertical movement around the coast. If you click on one of these dots you can view a graphed projection of sea level rise at that location until 2150 or 2300. This graph uses different colored lines to show the projected sea level rises under different climate change models. 

If you want to know how rising sea levels could affect other locations across the world you can use Climate Central's Coastal Risk Screening Tool. This interactive map allows you to see which areas around the globe are most threatened by sea level rise and coastal flooding. The map uses coastal elevation data with the latest projections for future flood levels to model how rising seas will impact all coastal communities.

The NYPD is Spying on You

There are thousands of surveillance cameras in New York which can track your movements around the city. The New York Police Department's facial recognition software can identify individuals as they move around New York and pass in front of any of the city's pervasive surveillance cameras. The system works using millions of profile pictures scraped from social media accounts without users' permissions. Black and minority communities are most at risk of being misidentified by facial recognition software and therefore most at risk of being wrongfully arrested.

Amnesty International, with the help of 7,000 volunteers, has analyzed Google Maps Street View imagery in New York to identify the locations of the city's security camera locations. Amnesty found and located over 15,000 surveillance cameras across the city.

In Inside the NYPD's Surveillance Machine Amnesty International has created a route finder which allows you to discover how many surveillance cameras you will pass on any journey in New York City. For example if you walk from the Empire State Building to the Museum of Modern Art you will be filmed by surveillance cameras on 80% of the journey. 

Amnesty claims that the pervasive level of surveillance in NYC coupled with facial recognition software means that you are 'never anonymous' in the city and that your movements can be tracked at any time. You can explore the density of the city's surveillance cameras on Amnesty's Decode Surveillance NYC interactive map. The Decode Surveillance heat-map shows the density of surveillance cameras across the city. You can view the locations of individual cameras by exploring the Inside the NYPD's Surveillance Machine interactive map.

Thursday, May 12, 2022

24 Hours of Global Flight Traffic

Google has released an animated map visualizing 24 hours of global flight traffic around the world. The WebGL Air Traffic Demo has been released to illustrate what can be achieved using the WebGL features of the Google Maps JavaScript API.

The WebGL overlay view in the Google Maps API allows developers to add and animate 2D and 3D graphics on top of a Google Map. In the WebGL Air Traffic Demo this feature has been used to create a visualization of one day's worth of flights longer than three hours between 645 airports around the world. The map is an impressive demo of the Google Maps API, animating thousands of data points at any one time. The map also includes an animated day/night layer which moves across the map to show the current time of day across the world. 

The WebGL Air Traffic Demo was demonstrated yesterday at Google I/O, where Google also gave a sneak peak of a new Immersive View' for Google Maps. Coming later this year for a number of global cities Immersive View combines satellite views, height data and Street View to create what looks like a truly impressive 3D map. The new 'Immersive View' hasn't been launched yet but Google did release a short video demo (shown above).

Wednesday, May 11, 2022

Global Plastic Watch

The world's plastic waste is now being mapped from space. Global Plastic Watch (GPW) has released a new interactive map which tracks the world’s plastic pollution in near real-time by using artificial intelligence to identify plastic waste sites in satellite imagery.

GPW's algorithms can identify plastic waste sites as small as 5x5 meters. By identifying and mapping sites where plastic waste is being dumped GPW can help governments and agencies around the world tackle the problem and help to prevent the flow of plastics into the oceans. 


one of 373 plastic waste sites identified in Indonesia

If you select a country on the interactive map you can view a country report which identifies the number of plastic waste sites found, the surface area of land being used for plastic waste, and the waste production per capita. Select an individual plastic waste site on the map and you can view the satellite imagery of the site for yourself, and (where available) even explore nearby Google Maps Street View of the site. 

You can see how plastic from individual waste sites is likely to reach the sea on an interactive map from Ocean Cleanup. The Plastic Tracker map allows you to track the probable journey that plastic waste is likely to take from any location to the ocean. Enter a location into the Plastic Tracker map and it will calculate the chances of a piece of plastic abandoned to the environment at that address reaching the ocean and will also map the journey that the plastic would likely take.

The Plastic Tracker map plots the journey that a single piece of plastic is likely to take from the moment it is discarded. It shows the possible route that the plastic would take to reach the sea based on data such as river flow, river mouth emissions and ocean currents. 

The Ocean Cleanup organization believes that between 1.15 to 2.41 million metric tons of the plastic in the oceans originates from the world's river systems. Two thirds of it from the rivers of Asia. The River Plastic Emissions to the World’s Oceans interactive map helps to visualize how and where that plastic ends up in the world's oceans.

This map shows river systems around the globe. The predicted input from each river system is shown at the coast using scaled circular markers. These predicted inputs are based on a model which looks at population density, waste management, topography, hydrography, the locations of dams and the reported concentration of plastic in rivers around the world.

Tuesday, May 10, 2022

Exposing the Horrors of War

Over the last two months reporters at the Washington Post have verified more than 200 videos documenting some of the atrocities carried out by Russia in its invasion of Ukraine. Since the beginning of the Russian attack on Ukraine ordinary citizens, soldiers, and officials have been using their phones to record the horrors carried out by the Russian army.

The Post has now organized these videos into a searchable database. Obviously many of these videos show the realities of war and can be distressing to watch. They record people losing their homes, their loved ones and even their own lives. All the videos have been uploaded in their raw format and the most graphic videos are clearly indicated as such by the Washington Post. 

The Post's Database of Ukraine Video can be searched by date and by keywords. An interactive map showing where each video was recorded also allows you to search the database by location. An animated map (shown above) also shows the location of all the videos, appearing on the map by the date of their recording.

You can also explore the terrible cost of Russia's invasion of Ukraine on the incredible 3D models created by Hidenori Watanave on his Satellite Images of Ukraine and 3D Data & 360 Panoramas Map of Ukraine.

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

Monday, May 09, 2022

A Still Life Map of the World

Jason Farago of the New York Times has published another close reading of a Dutch masterpiece. Over the last few years Farago has released a number of art essays which look closely at famous works of arts. Each of these art critiques owe a lot to the navigation and presentation techniques developed for online interactive maps. As you progress through one of his close readings an accompanying interactive zooms and pans around an image of the discussed painting to help illustrate Farago's observations of the artist's work.

In his latest close reading A Messy Table, A Map of the World Farago examines a still life by the 17th Century Dutch artist Willem Claesz Heda. In his essay Farago critiques Heda's painting 'Still Life With a Gilt Cup', while also exploring the wider context of the still life in art history and the genre's rising popularity in the booming economy of the Netherlands in the 17th Century.

By zooming in on each of the objects carefully arranged in Heda's painting Farago is able to illustrate the artist's skill. These opulent and exotic foods and objects also represent and signify a Dutch economy which is at the center of world trade.

Farago's previous critiques of individual paintings include:

 

If you are familiar with the Leaflet.js mapping library then you can create your own interactive painting critiques - using image tiles from paintings instead of map tiles. Museums and art galleries around the world use the iiif format to present artworks as zoomable images. This means that for many works of art, if they have a iiif manifest, you don't even have to create the image tiles for yourself.

The fantastic leaflet-iiif plugin allows you to seamlessly use iiif manifests with the Leaflet mapping platform.This means that you can quickly turn any painting with a iiif manifest into an interactive Leaflet map. You can view a demo of this in action on my The Drawing Lesson critique. In this scrollytelling examination of Jan Steen's painting (depicting an artist teaching two young pupils how to draw) I have used the Leaflet mapping library to take a close look at Steen's 17th century Dutch masterpiece. 

You can explore how my critique of the Drawing Lesson works by exploring the JavaScript code on its Glitch page. You can even clone the page if you want and use the page as a template for creating your own interactive scrollytelling painting essay. 

Sunday, May 08, 2022

Population By Latitude and Longitude

About 88% of the world's population lives north of the equator. One reason for this is that there is more landmass north of the equator and more ocean south of the equator. However the north of the planet has only around 68% of the world's landmass. This means that nearly 90% of the world's population is squeezed into the 68% of the world's landmass that lies north of the equator.

You can explore for yourself where the world's population lives in terms of latitude and longitude on Darren Weins' Lat/Lng Population Map. Hover over any location on this interactive map and a graph at the bottom of the map shows the population distribution along that line of longitude, while a graph running down the side of the map shows the population distribution along that line of latitude. 

The population data comes from Gridded Population of the World, Version 4 (GPWv4).

 

You can also view a distribution of the world's population by longitude and latitude on Andre Andersen's World Population Map. This population density map includes two graphs views, along the side and bottom of the map, which show how population is distributed across the world - both by latitude and by longitude. 

Engaging Data's World Population Distribution by Latitude and Longitude also creates a latitude and a longitude graph of the global population. This map shows the distribution of the world's population as a population grid. The map also includes two buttons which allow you to reorganize the population data. One button redistributes the world's population into a graph showing the population distribution by longitude. The other button organizes the population data into a graph showing the world's population distributed by latitude. 

Friday, May 06, 2022

Voice Controlled Maps

Steve Attewell's Voice Controlled Map is an interesting experiment in providing a more accessible interactive map with navigation controls that support vocal commands. This means that users are able to search and move around the map using a number of different spoken commands.

The map can be panned up & down and left & right, can be zoomed in and out, and can be moved to named locations all by spoken word. To enter a voice command just click on the 'listen for voice commands button' and speak to the map. If you want to know what actual words the map will understand then say 'commands' or 'instructions' to view a list of accepted commands. 

The Voice Controlled Map uses Ordnance Survey map tiles so can only be used in the UK. If you want to talk to an interactive map outside the UK then you can use Alex instead.

Alex is another interactive map which can be controlled by voice. Like Steve's map Alex can understand a number of different spoken commands. You can ask Alex to zoom in and out on the map or to switch between aerial and topographical map layers. You can even tell Alex a location and it will center the map on that area. 

Alex also talks back to you. As well as accepting spoken commands Alex can also speak. For example, for confirming when it has completed one of your commands. Or when Alex tells you a joke. Yes, ask Alex to tell you a joke and this interactive map will tell you a really bad cartographically themed joke.

Wednesday, May 04, 2022

The Importance of the Indian Ocean

The Strategic Importance of the Indian Ocean is a new interactive map which seeks to underline the strategic importance of the Indian Ocean as one region, stretching from the eastern coast of Africa to the western coast of Australia. The map provides an interactive tool for exploring the importance of the Indian Ocean to trade & global shipping, and to visualize the territorial claims of countries (some of which may provide barriers to that trade).  

The Indian Ocean holds a fifth of the world's waters and is critical to global shipping and to the economic fortunes of many countries. It is therefore a site of keen economic and strategic competition between many countries. One of the key layers on the interactive map shows the key shipping routes in the Indian Ocean and identifies key 'chokepoints' on these routes. These chokepoints are some of the most strategically important routes for world trade. As such disruptions at these chokepoints can have a dramatic impact on global trade.

The map also features layers on maritime boundaries, the important regional players and current maritime disputes in the ocean. There are currently 15 ongoing territorial disputes in the Indian Ocean. Some of which could have an impact on important shipping routes.

There are a number of territorial disputes on-going in the wider Asia Pacific region. The Asia Maritime Transparency Initiative has mapped out all these territorial claims in this larger area on its own interactive map.  The Maritime Claims of the Asia Pacific attempts to provide an as complete, accurate and up-to-date map as possible of all the competing maritime claims in the region.

On the map each country's territorial claims are shown using color-coded borders. The map includes a filter option which allows you to view any combination of countries' claims on the map. By selecting any two countries on the map it is possible to see exactly where they have territorial disputes.

The Asia Maritime Transparency Initiative map doesn't show territorial claims for the Spratly and Paracel Islands "due to a lack of clarity about what each country claims". 

Tuesday, May 03, 2022

Comparing Map Projections

Gall-Peters Map Projection Overlaid on top of the Mercator Map Projection
Gall-Peters and Mercator Map Projections

If xkcd's recent Madagascator cartoon map has sparked your interest in the use of map projections then you might like Compare Map Projections

Compare Map Projections is an interactive tool which allows you to view and directly compare 312 different types of map projection. Using the tool you can select to directly compare any two different projections. Which means the site provides 48,516 direct visual map projection comparisons, showing the differences and similarities, between any two of the 312 different projections.

In the Compare Map Projections 'simple mode' you can select any two of the 312 different map projections to view the two projections overlaid on the same map. For example, the map at the top of this post shows a Gall-Peters projection (in red) on top of a Mercator projection (in green). Comparing two different projections in this way provides a stark view of how projections distort our world view. Compare, for example, the huge difference in the size of Africa in the the Gall-Peters and Mercator projections (shown above).

a Tissot Indicatrix visualization of the Gall-Peters projection

Compare Map Projections also allows you to view a Tissot Indicatrix visualization using each of your chosen map projections. This visualization places a number of circles (all with the same land surface area) across the map. You can then clearly see how the selected map projection distorts different areas across the globe through the distortions of these equal sized circles. 



If you are interested in how different map projections distort the world then you will probably also like Projection Face. Projection Face is a great illustration of the distortions created by different map projections. The interactive shows how 64 different map projections effect our view of the world by showing each projection's effect when applied to something very familiar - the human face.

The distortions of each of the different projections can be illustrated further by clicking and dragging any of the mapped faces. This illustrates how the different map projections can be distorted themselves simply by changing the center of the map.

Projections Face is an interactive version of a 1924 illustration from Elements of Map Projection with Applications to Map and Chart Construction.
 



Comparing Map Projections is a clever visualization of different map projections. It allows you to directly compare different types of map projections to see the levels of distortions which each map projection introduces by visualizing a globe in two dimensions.

This interactive visualization provides a useful overview of the advantages and the disadvantages of specific map projections. For example if you select the much maligned Mercator map projection you can see that it scores very low for angular distortion. This means that all the lines of longitude are straight (compare the vertical lines of longitude on the Mercator projection to those on the Sinusoidal projection). The result is that a Mercator projection is really useful for navigation.

As you can see from Comparing Map Projections all map projections introduce some degree of distortion. 

  

If you want a little help deciding which map projection you should use for your current map project then you can use the Projection Wizard to decide on the best projection.

This map projection guide allows you to select the extent of the map view you are working with by outlining the area on a Leaflet map. Once you've highlighted your map bounds you can choose a distortion property (Equal-area, Conformal, Equidistant or Compromise).

The Projection Wizard will then suggest which map projection you should use depending on the extent and the distortion property of the map. The suggested projections are based on 'A Guide to Selecting Map Projections' by the Cartography and Geovisualization Group at Oregon State University.

A Proj.4 link is provided next to each suggested projection, which opens a popup window with a Proj.4 library. Once you've settled on your map projection you might want to check-out the Proj4Leaflet plugin for using projections supported by Proj4js with Leaflet powered maps.

Monday, May 02, 2022

Madagascator & Mexicator

xkcd has published another fun, map based cartoon. Bad Map Projection No. 248: Madagascator is a world map which uses the Mercator projection "but with the North Pole in the Indian Ocean so that it exaggerates the size of Madagascar instead of Greenland.' 

The map is a great way to visualize how the Mercator projection distorts size the more you move away from the equator. Because Mercator is so ubiquitous we are used to Greenland appearing as if it as large as the whole continent of Africa. Using the Madagascator projection Greenland appears much smaller than Africa (which it is). Unfortunately Madagascar now appears to be the size of Canada (Madagascar is 587,041 sq km, Canada is 9.985 million sq km).  

Mexicator - a Mercator projection map using Mexico as the North Pole

While Bad Map Projection is a great illustration of how the Mercator projection distorts our perception of the Earth much more fun can be had by actually clicking on the cartoon map. xkcd 2613 is also a hotlink to Mercator Extreme. Click on the Madagascator map and you will be taken to Drew Roos' interactive Mercator Extreme map.

Mercator Extreme is a fantastic interactive map which allows you to set any location on Earth as the North Pole and visualize the resulting Mercator Projection distortion created as an interactive map. Type in your address into the map and you can visualize what a Mercator Projection map of the world would like if your home was the North Pole. 

You can also play around more accurately with the Mercator projection on the Mercator Projection Explorer. The map above shows a world with Mexico as (approximately) the North Pole.

a Winkel Tripel map projection with the Indian Ocean as the North Pole

You can explore how other map projections distort the world using Jason Davies' Map Projection Transitions. Choose from any of the many different map projections provided in Map Projection Transitions and you can then drag the world map to explore how the chosen map distorts different countries. It is the perfect application for illustrating how all maps have to make compromises somewhere when trying to represent a three dimensional world in only two dimensions.