Map Your City from Memory

Alasdair Rae of Stats, Maps and Pix has decided to run an experiment on people's perceptions of their town or city boundaries. He has therefore released an interactive map which allows anyone to draw where they think the boundary of their home town is.

Draw Your City allows you to zoom in on any location in the world. You can then draw an outline around your town or city, showing the extent of your town or city's boundary. After drawing your boundary you then can say how long you have lived at the location and leave a little comment about the location.

If you click on the 'View Maps' link you can also view all the boundaries that other people have drawn. This allows you to see how close your concept of your town's size conforms with other peoples. If you click on a boundary on the map you can also read the comments that other users have left.

Alasdair's project is based on Colin Ross' Where is Sydney?. Colin's map is in turn inspired by the Neighborhoods Mapping Project. All three mapping projects use Nick Martinelli's crowd-sourcing neighborhood boundaries code, which is available on GitHub.

Global Warning on the Eastern Seaboard

The New York Times has published an interesting visualization of the rising sea levels and increased coastal flooding along the whole Eastern Seaboard. A Sharp Increase In ‘Sunny Day’ Flooding
argues that flooding caused by global warning along the Atlantic and Gulf Coasts has already begun. The accompanying visualization goes a long way to prove that the argument is correct.

A strip map of the Atlantic and Gulf Coasts, from Maine to Key West, runs down the left-hand side of the page. As you scroll down through the visualization, photos and sea level graphs on the right of the page, provide information about the increasing threat of tidal flooding along the Atlantic and Gulf Coasts.

The graphs plot the mean sea level rise and days of flooding from 1950-2015 for a number of locations along the Eastern Seaboard. All the location graphs show a rise in sea levels and nuisance flooding over this time period. These rises appear to be increasing even more sharply over recent years.

Mapping London Traffic Accidents

Visualizing TFL Accident Data is an interactive map of 2015 traffic accidents in London. The map shows the locations of Transport for London recorded road accidents across the capital.

The circular markers on the map are scaled to visualize the number of accidents at a location and color-coded to show the severity of each accident. If you select a marker on the map you can view details on the type of vehicles involved and the age of the victims.

You can filter the data shown on the map using the graphs in the map side panel. If you click on the vehicle icons you can select to view traffic accidents by vehicle type. You can also filter the results by age group and by the severity of the accident.

The map itself was created with the Google Maps API and uses D3.js for the scaled markers and the data charts used in the side panel.

Parallax Map Markers

Leaflet.Parallax.Marker is a plug-in for Leaflet.js that allows you to create map markers with a parallax effect. The plug-in makes the markers move, when you pan the map, at a different speed to the basemap.

Leaflet.Parallax.Marker comes with two demo maps. One shows the parallax effect added to place labels. Four different sizes of place labels are used in the demo. Each of the four different sized labels is given a different 'parallax offset' so that they appear to move independently of each over. The result is that the place labels have a parallax effect in relation to the basemap.

The second demo uses clouds as the map markers. This creates a map with clouds that appear to float over the basemap when you pan around.

Maps of the Week

Climatemaps visualizes the weather over the course of a year around the whole world. The map animates average global monthly climate data from 1961-1990 to show you when every location in the world has its hottest, driest or wettest weather.

You can select from a range of weather layers from the drop-down menu (including precipitation, cloud cover and average temperatures). You can then view the weather data animated on the map through a whole year (you might need to let the animation play through a couple of times before the layers load completely).


A new crowd-sourced tool plans to monitor deforestation and other environmental damage caused to the planet around the world. Map for Environment uses OpenStreetMap mapping tools with satellite imagery of known logging, industrial agriculture, dam, and fracking locations to help map how these industries are effecting the environment.

If you log-in to Map for Environment with an OpenStreetMap account you can begin to help map logging roads, the spread of industrial agriculture, dams and fracking sites. You can also view the work already logged on four animated maps. For example you can observe the huge spread of logging roads in the Congo Basin on the animated Logging Roads map. This map uses historical satellite imagery to show the spread of logging roads in the Congo Basin over recent years.


Speigel has created a fascinating visualization of the regional variations in the German language. More than 670,000 people throughout Germany were asked which words they used for 24 common terms. The regional differences in their answers were then plotted on an interactive map.

To create the Alltagssprache map Germans were asked what words they used for various terms, such as pancakes, meatballs and chatting. The interactive map plots where Germans used different words for these common terms. The different colors on the map show were the various different words were used. The opacity of each color shows how common a particular word was used at that location,

You can use the forward and back buttons at the top of the interactive map to browse through the visualizations of each of the 24 tested in the language survey.

Global Forest Watch Water

This week Global Forest Watch launched a new interactive map to monitor the health of watersheds around the world. Global Forest Watch is a global forest monitoring network, designed to map the world's forest coverage and loss.

The new Global Forest Watch Water map also allows you to identify threats to watershed health anywhere in the world. If you click on the map you can view a watershed summary for the selected location based on local risks to the watershed, such as forest loss, erosion and fire. You can view a watershed risk summary for the selected location and click through to read a full report.

You can an add an overlay to the map to view wetlands and water-bodies. You can also add a number of overlays which visualize possible watershed risks, for example tree cover loss, erosion and baseline water stress.  

Mapping the Great Fire of London

350 years ago on September 2nd 1666 the Great Fire of London began in a bakery on Pudding Lane. By September 5th the fire had destroyed 13,200 houses, 87 parish churches and St Paul's Cathedral. The BBC has created an interactive map and the diary entries of Samuel Pepys to recount the four days when London burned.

Retrace Samuel Pepys' Steps in the Great Fire of London shows the extent of the fire in red. The orange lines show the approximate extent of the fire on each day. The grayed out area shows the approximate edge of London in the 17th Century. The map sidebar contains Pepys' diary entries about the fire, in chronological order. If you click on the headline for each entry you can view Pepys' location for that entry on the map.

The BBC map also includes a number of other markers highlighting important buildings which survived the fire and a number of images of London in the 17th Century. The map tiles and labels have been styled to give the map a suitably vintage feel. However, if I had made this map, I would have used an original 17th Century map or at least given the user the option to view an historical map as a map overlay or layer.

Mapping Gentrification in L.A.

A joint project from the UCLA and UC Berkeley is mapping gentrification and displacement in L.A.'s neighborhoods. The Urban Displacement project monitors where gentrification has happened or is currently happening in Los Angeles County.

You can explore the project's findings on an interactive map which shows which neighborhoods have gentrified over the last twenty years. The map also allows you to view other demographic and economic data about Los Angeles' neighborhoods side-by-side with the gentrification data.

Among the key findings of the project is that neighborhoods around public transit stations are the most likely to be affected by gentrification and displacement.

The Urban Displacement project is also mapping displacement and gentrification in the San Francisco Bay Area.

Read the National Geographic in Leaflet.js

The September 2016 issue of National Geographic includes a supplement poster exploring life in the Pacific Ocean off British Columbia. The poster includes two sides. One side is an illustration of life under the waves. The other side is a map of British Columbia and the Atlantic Ocean.

National Geographic has created a Leaflet.js powered map from the poster so that you can view it online. The British Columbia Supplement map allows you to zoom in and out on both the National Geographic illustration and the Atlantic Ocean map.

If you want to create your own interactive map from an illustration, photo or other still image then you could start by looking at Zoomable Images with Leaflet (tutorial explaining how you can use GDAL2Tiles and MapTiler to render map tiles from an image) or Showing Zoomify Images with Leaflet.

Scotland's Most Deprived Areas

The most deprived area in Scotland is Ferguslie Park in Paisley. Glasgow continues to the most deprived city. Nearly half of Glasgow's neighbourhoods are in the bottom 20% of deprived areas.

The Scottish Index of Multiple Deprivation 2016 allows you to explore the most and least deprived areas in all of Scotland on an interactive map. The map shows the most deprived areas in red and the least deprived in blue. If you just want to find the most deprived neighbourhoods in your area then you can use the buttons in the map menu to display only the Most Deprived 20%, the Most Deprived 10% or the Most Deprived 5%.

If you hover over an area on the map you can also find out how the neighborhood ranks in each of the Index's standards. These standards measure deprivation indicators such as income, employment, crime and health.