Inspried by Shigeru Kobayashi‘s work and the desire to just make something, I created a google map visualisation of radiation readings from across Japan. These are crowd-source readings from numerous geiger counters hooked up to the Internet. The folks at Pachube have aggregated these readings and made them available for people to play with. The readings come from sources such as local councils, motivated individuals and official readings from Japan’s Ministry of Education, Culture, Sports, Science and Technology (MEXT). My aim with this map is to make the data easily readable and understandable, so people can very quickly get an overview of the radiation levels across Japan and are able to drill in to get further details per region. From a user experience point-of-view, I wanted the numbers to be at a glance, avoiding the extra clicks that these mashups usually ask of the user. So you see the readings highlighted in yellow on the map. The orange circles are coloured based on the severity of the reading (the darker the orange, the higher the reading). Clicking on these circles will also bring up more details about the reading (location, timestamp, millisievert).
The toughest part of this visualisation is really understanding what the numbers mean and what impact they have on human health. The first step to this process is standardising the units of measurement, as the crowd-sourced measurements and visualisations may use a number of representations. Units here are in µSv/h (or microSieverts) and we’ve been hearing CNN and NHK World refer to the unit Milisieverts (1 miliSievert = 1000 microSieverts). I also urge other mappers out there to use the µSv/h unit, so we speak a common language.