May 022012

Parthenium hysterophorus imageInvasive plants in Tanzania are becoming a big problem … in a ‘potentially collapse the economy’ sort of way. For one, Parthenium is spreading rapidly here and in the region, and Ethiopia has seen a loss of more than 25% of its rangelands in the past decade. The Conservation Resource Centre has an article on this.

Monitoring the spread of Parthenium and other plants is tough – there are few national resources to do this, and Tanzania’s a big place, but there are a lot of people who are interested in the issue.

We’re trialling Crowdmap (the excellent Ushahidi application) to try to use reports from  just about anyone to see where it is and how it is spreading. See the live map below to get an idea. Go to to try it out.

Ushahidi is a great application for crowdsourcing information. It lets people submit information online, via email or text message, and there are some great Android (and probably iOS) apps that integrate reporting, camera and GPS positions. As reports come in, they can be confirmed by administrators to confirm correct observations, or indicated as ‘possible’ if ID is uncertain.

Please help out if you’re in the region! See the steps below – those marked !! are VERY important for tracking.

  1. Sign up for an account – it’s free, but please use your real details as we’ll need to track who and where the information is coming from.
  2. Click on “Submit a report” on the main page.
  3. Give the report a brief title – location and scale are good.
  4. Enter a brief description
  5. !Confirm the date and time – you can enter older data (something you saw last month or year) but make sure you have the date correct to within a week or two. This lets us track changes over time.
  6. Enter the categories: Definite Parthenium sighting, probable, or absence in a wide area.
  7. Land use: what kind of habitat was it in?
  8. !Patch size: Single plant? Lots of them?
  9. Density: estimate how many per 100x100m plot (one hectare).
  10. !Map: you will drag the red marker on the map and zoom in to the area where you saw the sample. Zoom in as much as possible, dragging the red marker each time you zoom to a more accurate position. If you used a GPS, just enter the coordinates in the box below the map (near the “Find Location” button).
  11. !Accuracy of position: How close to the map position do you think the sighting was? It’s OK to be +/- hundreds of metres, or even a  few kilometres, but TELL US if you’re unsure (null)!
  12. !! Type of observation: did you see it yourself, or hear about it?
  13. !Refine Location Name: this is an important identifier to describe your sighting; give it as accurate a name as you can, i.e. “Corner of Nairobi and Sokoine Roads, Arusha”, or “25km from Dodoma on main highway”.
  14. Upload photos: did you get a picture? It’d be good to get the photo uploaded, especially if you’re unsure of the identification.
  15. SUBMIT – make sure you do this or we don’t get the information!
If you’re posting for the first time, we may contact you about your identification; it will take up to 24 hours for the map to be updated so be patient!


More articles and resources:


  One Response to “Web mapping and crowdsourcing: tracking Parthenium”

  1. […] Invasive plants and crowd sourcing Share this:Related Posts:No Related Posts  Posted by ragnvald at 12:45 […]

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