23 September 2020 - 23 October 2020
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New Geo-Wiki Global Built-up Surface Validation Campaign Launches 23 Sep 2020

Join our new campaign to contribute to science and win prizes!

Photo by bantersnaps on Unsplash

Photo by bantersnaps on Unsplash

We are excited to announce the start of a new campaign to help us validate a global built-up surface layer produced by the Joint Research Center of the European Commission called the Global Human Settlement Layer.

As in previous campaigns, we will ask you to shade the grid cells if they contain any built-up features. We will aim to validate 50K points at least 5 times during the campaign, which will launch on 23rd September 2020. Put this date in your diary and join our campaign, with prizes and co-authorship to be won for participation.


  • Top 11 contributors will earn an Amazon voucher (valued from 175 to 500 Euros) AND co-authorship on a peer-reviewed scientific journal paper summarizing and making openly available the information collected.
  • Contributors ranking between 12 and 25 on the leaderboard will be offered a choice of an Amazon voucher of 100 to 150 Euros, OR, alternatively, co-authorship on a scientific paper.
  • Contributors ranking between 26 and 30 on the leaderboard will be offered an Amazon voucher ranging between 50 to 75 Euros.

To join our campaign, go to the Geo-Wiki website (https://www.geo-wiki.org) and click on Launch or click here to go directly to the login page.

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Last edited: 22 September 2020


Linda See

Senior Research Scholar Novel Data Ecosystems for Sustainability Research Group - Advancing Systems Analysis Program

T +43(0) 2236 807 423

Ivelina Georgieva

Research Assistant Novel Data Ecosystems for Sustainability Research Group - Advancing Systems Analysis Program

T +43(0) 2236 807 357


Lesiv, M. , Laso Bayas, J.C. , See, L. , Dürauer, M., Dahlia, D., Durando, N., Hazarika, R., Sahariah, P.K., et al. (2019). Estimating the Global Distribution of Field Size using Crowdsourcing. Global Change Biology 25 (1), 174-186. 10.1111/gcb.14492.

Laso Bayas, J.C. , Lesiv, M. , Waldner, F., Schucknecht, A., Duerauer, M., See, L. , Fritz, S., Fraisl, D. , et al. (2017). A global reference database of crowdsourced cropland data collected using the Geo-Wiki platform. Scientific Data 4, e170136. 10.1038/sdata.2017.136.

See, L. , Fritz, S., Dias, E., Hendriks, E., Mijling, B., Snik, F., Stammes, P., Vescovi, F.D., et al. (2016). Supporting Earth-Observation Calibration and Validation: A new generation of tools for crowdsourcing and citizen science. IEEE Geoscience and Remote Sensing Magazine 4 (3), 38-50. 10.1109/MGRS.2015.2498840.

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