Geoinformatics

Wednesday, March 7, 2007

BIODIVERSITY CARTOGRAMS

I got inspired and have been experimenting with the prepartion of cartograms[1]. The data used is biodiversity-related and includes the degree of threat and rarity of species extracted from the IUCN Red Data list of threatened species, with the link to the site here.

Unfortunately, I did not have the latest data prepared as GIS layers, so this is for the year 2000. This will be the sort of exercise you might be expected to do in your eco/geo-informatics programme: getting the latest biodiversity data from the IUCN Red Data list, prepare the data as a GIS layer and present it as cartograms. You will be expected to discuss your results and to post your article on the Weblog for general discussion, complete with a reference list.


Continents of the World


The cartograms have scaled each country's size to the value of the variable (e.g. number of threatened fish species). Further the maps are thematically shaded with red indicating the highest value of threatened or endangered status going through orange, yellow, light green to dark green which represents the lowest values.


Number of plant extinctions


Percentage of threatened plants in the flora


Number of rare plant species


Total number of plant species


Number of threatened invertebrate species


Number of threatened fish species


Number of threatened amphibian species


Number of threatened reptile species


Number of threatened bird species


Number of threatened mammal species


As you can see South Africa is a Biodiverse region that has high risks of extinction, especially for plant species.


Reference
[1]Gastner, MT and Newman, MEJ 2004. Diffusion-based method for producing density-equalizing maps. Proc. Natl. Acad. Sci. USA 101, 7499-7504.

1 Comments:

  • Hi, that's very nice! As I'm creating maps on ARCGIS, I'm wondering if there's a script I could use to create this cartograms (and not having to implement the stuff by myself)

    Best regards

    Stephan

    By Blogger Stephan, at March 20, 2007 at 5:33 PM  

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