Geographic visualization in social sciences – or draw more maps! Continue reading
Tag Archives: geovisualisation
On the grid: Worldmapper and beyond
My research on gridded cartograms has its roots in the works of the Worldmapper project, which was originally released in 2006/07 and extended in the following years. While the first phase of the Worldmapper project has visually describes the world, mapping the national contours of hundreds of variables, it did so only in one way and a way easily open to criticism despite its novelty and wide scope. To tackle this, I conducted further research to help address these potential criticisms, to work on moving the resource beyond its simple descriptive form. This included a look at more theoretical issues of how world resources, flows and shares are understood, particularly visually understood – and how this can be improved.
The gridded cartograms are one of the key results of this second phase of the Worldmapper project to advance and improve the capabilities of the Worldmapper maps. So far we integrated gridded cartograms on the Worldmapper website only in form of the World Population Atlas that shows an extensive collection of gridded country cartograms. These are the first ever made compilation of maps showing population distributions in cartogram form at that level of detail for every country of the world, but there is more to the underlying technique than this.
Following the release of these first maps using a gridded cartogram approach, I have made progress not only in enhancing the accuracy and quality of these country-level maps, but also in advancing the technique to a stage where gridded cartograms can be utilised as an alternative map projection (explained and discussed in full detail in my PhD thesis). Some examples are shown on this website: One example for the new capabilities at country level is the map of population changes in Germany. At global level the example of agricultural spaces presented at last year’s Annual Meeting of the Society of Cartographers demonstrates their applicability not only for population-related issues, but beyond that for other quantitative dimensions with a new level of detail, but also new capabilities of showing additional layers of information that the original Worldmapper approach was not capable of achieving.
There sometimes is a certain confusion about the differences between the maps drawn in the first stage of the Worldmapper project (and that we carry on producing as well), and the new gridded cartograms. The following map series shows the differences by using the Worldmapper colour scheme applied to the different map types (for full clarity, the map series starts off with a conventional map projection):
The Visualisation of Spatial Social Structure: Reflections on Critical Methods
‘(How) do we understand Capitalism? Reflections on critical methods’ was the title of a workshop on critical methods at the University of Manchester (September 13-14th). As the announcement of the workshop states, ‘there is no consensus on what critical social science is, exactly. Largely it is defined as not orthodox economics or positivist social science‘. Continue reading
From geovisualisation to neocartography: Maps in a digital world
Changing technologies have always had a considerable impact on cartography and continue to do so. Several technological revolutions marked important steps in the practice and process of creating maps. Mechanical, optical and photo-chemical technologies changed the way maps were produced. Then, the discovery of electronic capabilities made a new dimension in map production accessible: Not only most of the design techniques were transferred to digital platforms, used at some step in the production of almost all maps created today, but also the possibility to deal with huge amounts of data that can hardly be analysed by a single person enables cartographers to find ways to automate data processing for cartographic visualisation. This is where the term neocartography comes into play, which gives credit to the most recent trends in the field of map-making. Continue reading
Megacities and Earthquake Risk
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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People at Risk: Visualising Global Earthquake Intensity
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).
