Declan Butler, reporter This is the personal blog of Declan Butler, a senior reporter at Nature. All views expressed here are mine, and not those of Nature. Contact me at

April 22, 2011

A population density map to help provide context to my nuclear power plant proximity analysis

Filed under: Energy,Google Earth,Nuclear,Uncategorized — admin @ 9:50 pm

Following on from the population analysis I published yesterday estimating quantitatively how many people live within certain distances of each of the world’s nuclear power plants, some people have asked me for more information on population distribution itself, and whether it might provide more spatial context for the results of the analysis — for example is the plant close to urban sprawl from a major city. Or why is it that nuclear power plants in France, for example – which with 58 nuclear reactors, is second only to the United States (which has 104) in terms of numbers of nuclear reactors — tend to have fewer people living near to most of them, compared with, for example, much smaller nuclear power nations such as Germany?

So to try provide some more visual geographical context, today I’ve mashed together the results of the analysis I published yesterday in Nature — see here my 3D map of the results of that analysis — with a new very high-resolution global population density Google Earth map for 2010 created by the NASA Socioeconomic Data and Applications Center operated by Columbia University’s Center for International Earth Science Information Network (CIESIN). The underlying data is the same as we used in our previous analysis.

Mashing the two maps together certainly does provide this sort of greater context, but the result of combining them is also a bit visually overwhelming, and may be confusing at first. — so beware.

Here’s a screenshot — you can find the full 3-D interactive mashup of the two maps below the fold.


April 21, 2011

A GIS analysis of the number of people living near each of the world’s nuclear power plants

Filed under: Energy,GIS,Google Earth,Nuclear,Nuclear accidents,Uncategorized — admin @ 10:19 pm

I’ve published in Nature tonight a GIS analysis I did with the NASA Socioeconomic Data and Applications Center operated by Columbia University’s Center for International Earth Science Information Network (CIESIN), looking at how many people live within certain distances of each of the world’s nuclear power plants.

It shows, for example, that two-thirds of the world’s power plants have more people living within a 30-kilometre radius than the 172,000 people living within 30 kilometres of the Fukushima Daiichi plant. Some 21 plants have populations larger than 1 million within that radius, and six have populations larger than 3 million. One hundred and fifty-two nuclear power plants have more than 1 million people living within 75 kilometres.

I’ve published the full results in the form of a map which is best viewed using the desktop version of Google Earth — you can download my map file here. The map plots every one of the world’s nuclear plants with circle size indicating the number of people living within 75 km of each plant. Moving the mouse over any circle brings up a label, and the figure for the size of the population. Clicking on any of the plant symbols opens up an information panel showing data for population estimates at 30, 75, 150 and 300 km from the plant, as well as the total power output, and a photograph of the plant.

I did this map fairly quickly, and will add a scale etc soon. Feedback welcome. I can also be contacted at

I’ll try to publish soon the full raw dataset that we created.

Here’s a screenshot of just one of the plants on the map: Indian Point, near New York.


How population sizes were estimated

To estimate the size of populations living near nuclear power plants, Nature first created a map, based on the Power Reactor Information System database, an up-to-date database of nuclear reactors that are operational or under construction, supplied by the International Atomic Energy Agency (IAEA). The IAEA does not provide latitudes and longitudes for the reactors, so we obtained many of these by doing a database merge with the older UNEP-GRID reactor database, which contains data, including geographical coordinates, on reactors up to the year 2000. We manually geocoded remaining entries that lacked coordinate data.

To derive the population estimates, Nature teamed up with CIESIN, whose Global Rural-Urban Mapping Project (GRUMP) population database is one of the best available data sets of global population density. The team, and in particular CIESIN scientists Kytt MacManus and Liana Razafindrazay, overlaid the reactor map with GRUMP population maps for the years 2000 and 2010 in a geographic information system and computed population estimates for both years using concentric zones drawn at 30, 75, 150, 300, 600 and 1,200 kilometres from each nuclear power plant.

April 2, 2011

The world’s nuclear reactors as you’ve never seen them…

Filed under: Nuclear accidents — admin @ 8:50 pm

I haven’t been blogging here for a while, but I thought I’d crosspost this one, which I published earlier over on Nature’s blog.

The nuclear accident at the Fukushima Daichii power plant will have consequences for the future of nuclear power in Japan and elsewhere. To get a better idea of the world’s current tally of nuclear reactors, I’ve created a map of the world’s nuclear power plants and reactors using Google Earth – the maps are based on a database kindly supplied to me by staff at the International Atomic Energy Agency’s (IAEA) Power Reactor Information System (PRIS) database, so it’s reliable, and up-to-date. The database, however, lacked latitude and longitude data — I obtained many of these by doing a database merge with the older UNEP-GRID reactor database which contain data on reactors up to the year 2000, and then geocoded the remaining entries lacking coordinate data.

Google Earth, with its unparalleled pan and zoom functionality and the relative ease with which it can be interfaced with databases, is my preferred tool for mapping and visualizing geographical data. Here’s the link to my beta map – remember that to view the file you must first download Google Earth (I’ve also done these maps in my spare time, so please be forgiving of any rough edges)

Here’s a quick summary of what the map shows:

1. All the world’s nuclear power plants are depicted on the map as circles. Their names appear in yellow on browseover, with the size of the circle proportional to their total MW electricity output. I calculated the MW output by summing that of the plant’s operational reactors, plus that of those already under construction.

2. Where it gets more interesting is that if you zoom in and then click on a power plant, its circular symbol will open up to show each individual reactor at the plant, with the colour of the circle of each reactor depicting its design (for example, “boiling water reactor”). Then clicking on any reactor will bring up an information panel, giving the reactor’s basic technical details, and where available a photograph of the plant, as well as links to recent news stories about the plant.

A major advantage of Google Earth is that it is also easy to overlay other layers of data on top of this base map of nuclear power plants and reactors, so (time permitting) I could envisage, for example, adding such relevant geographical layers as datasets on population density, past significant earthquakes and tsunamis, as well as seismic risk. Let me know what sort of data you would like to see added as supplementary layers. But for now, I thought I’d just get the base map out the door.

For full coverage of the Fukushima disaster, go to Nature’s news special.

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