Category Archives: maps

Megacities and Earthquake Risk

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Read more about this map:
Paper in the Journal of Maps: Gridded cartograms as a method for visualising earthquake risk at the global scale

The following map is a modified version of the earthquake vulnerability map published on this website last month (see that page for more details on the underlying earthquake map). The map itself does not show much new information, but includes an aditional layer containing the largest cities of the world, the so-called megacities (depending on the definition, these are cities with a population of more than 5, 8 or 10 million). The circles reflect the category in which each city belongs (based on 2015 estimations by the UN), and they are placed on the location of the city related to the total population distribution. As the map is resized according to the population (equal-population projection), the map also help to understand the setting of each city within the global population density, explaining why the artificial boundaries of a city do not always tell the full story of the urban population structure within a region. In some areas, such as Hong Kong and Guangzhou in the Pearl River Delta, cities are just one of several centres in a highly urbanised region – an urban sprawl – while other megacities like Mexico City or Moscow are in a more solitary location (although even here the extent of the populated area goes beyond the urban boundaries, and certainly the population is far from solitude). Without the city labels the map already showed the relation between human settlements and earthquake risk. The following map now allows to better understand the underlying geography if one is not so familiar with that kind of map transformation.
On a more technical note, the following map feature also includes another jQuery feature (I experimented with the image slider applied to maps on the earth at night map): This map uses the Zoomy Plugin to reveal a more detailed version of the map using an interactive magnifier. Click on the map map to enable the magnifier and see more detail (or if you don’t like that, click here for the usual large version of the map).

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Views of the World at Night

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The Sendai earthquake in Japan sparked a debate about sustainable energy supplies of industrialised countries – with a controversial discussion about the safety and sustainability of nuclear power. The book ‘Sustainable Energy – without the hot air‘ by David MacKay is an outstanding read in this regard, outlining the all key issues that matter for our future energy need (the digital version is free, although I recommend the paperback which can even be read without wasting any electricity).
Switching the lights off was not a matter of choice for many people in the North of Japan after the devastations of the earthquake also affected the energy supplies (not only because of the Fukushima accident, but also because of a widely destroyed basic infrastructure). Another image featured in the NASA Earth Observatory takes a closer look at the electricity losses that occurred after the Earthquake by creating a composite image of two images of lights observed in 2010 and after the earthquake at March, 12 this year. As a highly industrialised country, the illuminated areas in Japan usually show the places where people live (see worldmap below), while dark areas are the unpopulated regions, hence the reprojection on a gridded population cartogram results in a dominantly bright image. Using NASAs display of the electricity losses therefore gives a good representation of the number of people affected by the power losses (and largely also the Tsunami and Earthquake itself) in the Northeast: The redrawn version of the image shows these as the red areas, while the brighter yellow areas in the South and West show the regions that has a similar illumination compared to the previous image. This is how ‘Japan at Night’ looked after the 2011 Earthquake:
Japan at Night after the 2011 Earthquake displayed on an Equal Population Cartogram Continue reading →

World Water Day

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World Water Day 2011

Water is a basic requirement for all life, yet water resources are facing increasing demands from, and competition among, users. In 1992, the UN General Assembly designated 22 March of each year as the World Day for Water
(quoted from the WWD website).

Water is more than a chemical substance contains one oxygen and two hydrogen atoms. Water has become a reason for conflicts and a controversial commodity, and yet, it is inevitable for every human being on the planet. The range of issues that are important when looking at water is diverse, and all fields reveal the global inequalities in access to clean water. One of these issues is the commercialisation of water, which on a global scale finds its manifestation in the bottled water industry: Bottled water is one way of getting access to clean water if there is no reliable central water supply or local source of water.
Edward Stanley from University College London looked at the bottled water business for a Geography dissertation project, for which I created some worldmapper maps visualising his data from that research on ‘Commodification and Mass Consumption – The Case for Bottled Water‘.
The topics that we mapped focus on the countries of origin of the globally operating bottled water companies and the bottled water consumption in the world. The first map shows the total bottled water consumption including a world population cartogram as a reference. In addition, the countries are shaded by their per capita consumption of bottled water (a worldmapper-style version of this map is shown at the bottom of this page):

Map I: Global Bottled Water Consumption (total and per capita)Cartogram / Map of the Global Bottled Water Consumption (total and per capita)(click for larger view)

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Mapping people, not sheep: Why our planet’s well-being can look so different

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Today I held a talk at the IDEA CETL Applied Ethics Research seminar at the University of Leeds. My talk was titled ‘Mapping people, not sheep: Why our planet’s well-being can look so different’ and focused on issues of mapping well-being in new ways. Continue reading →

People at Risk: Visualising Global Earthquake Intensity

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Read more about this map:
Paper in the Journal of Maps: Gridded cartograms as a method for visualising earthquake risk at the global scale
University of Sheffield Press Release
German-language news article: Weltkarte zeigt Menschen in Erdbebengefahr

Besides all the disturbing images in media, the devastating Japan earthquake has already been intensively documented in the world of mapping, ranging from USGS’s geophysical maps, ESRI’s Social Media mashup, and media features such as the excellent New York Times features (see here and here). More online map and imagery resources have been compiled by the editors of Directions Magazine (see here). Similar responses could already be observed during the Christchurch earthquake, which demonstrates, how fast such information is released and processed nowadays.
The following map shows a more general approach of mapping the risk of earthquakes. It is a visualisation of all major earthquakes that have been complied in the Global Significant Earthquake Database. The database created by NOAA’s National Geophysical Data Center “contains information on destructive earthquakes from 2150 B.C. to the present that meet at least one of the following criteria: Moderate damage (approximately $1 million or more), 10 or more deaths, Magnitude 7.5 or greater, Modified Mercalli Intensity X or greater, or the earthquake generated a tsunami“.
Following an approach of spatial-analyst.net, a kernel density has been calculated from these records to visualise the areas most at risk of earthquakes during that time period. In a last step, I have transformed the world earthquake intensity map (see map inset) using a density equalising cartogram algorithm applied to a population grid. Simply said, the resulting map gives each person living on earth the same amount of space while also preserving the geographical reference. This map allows to understand the earthquake intensity in relation to today’s population distribution, and thus gives an idea of where most people are of risk related to seismic activity (there is an updated version of this map showing labels for the world’s largest cities here: Megacities and Earthquake Risk).

Global Earthquake Intensity Map visualised on a gridded population cartogram.
(click for larger map)

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A Population Map of Tibet

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The 10th March is a controversial day in the history of Tibet: It marks the anniversary of a failed uprising against Chinese rule in 1959 and thus contributed considerably to todays political state. As the Tibet Autonomous Region it is now governed as a Chinese province, and political demands for an independent Tibet regularly find their way into the public debate. The latest in these developments is the announcement of the spiritual leader of Tibetan Buddhism, the Dalai Lama, to retire from political life. While the Tibetan Parliament is a government-in-exile, ethnic Tibetans are estimated to make up 93% of the population within the Tibet Autonomous Region, with an increasing rise of Han Chinese in the last decades. The total population living in Tibet is estimated to be 2.91 million, and the region has China’s lowest population density, with only 2.2 people per square km. Hence it is no surprise that the gridded population cartogram of China in the world population atlas gives Tibet little space in the map there (situated below the larger bulge that is Urumqi, and by far degraded by China’s populous Eastern provinces). To get a better picture of the population distribution within the region, I created a gridded population cartogram for the area of Tibet which gives a more detailed impression of the Tibet’s population distribution (using the boundaries of the Tibet Autonomous Region). The population cartogram also includes a transformed topographic display that illustrates at which elevations most people live in this region that is the highest region on earth :

Population Map / Cartogram of Tibet
(click for larger map)

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