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A crowdsourcing tool for environmental and socio-economic monitoring.
Type of site
Available inEnglish
Country of originAustria
Created byInternational Institute for Applied Systems Analysis
IndustryCitizen Science

Geo-Wiki is a platform for engaging citizens and experts in both environmental and socioeconomic monitoring, established in 2009 at the International Institute for Applied Systems Analysis (IIASA). It aids in both, the validation of existing geographical information and the collection of new geographical information through crowdsourcing[1][2] and citizen science.[3] Using data sources such as satellite imagery, geotagged photographs and the Internet, individual volunteers are able to contribute valuable in-situ data, either by validating existing data and comparing it with satellite imagery (through visual interpretation), or by collecting new information. Other methods for crowd-sourced data collection in Geo-Wiki include campaigns and games, used as incentives to motivate citizens. Collected data in the platform is freely available.

By 2020, Geo-Wiki had more than 15 000 registered contributors, and many successful citizen science campaigns, collecting data on topics such as global built-up surface validation, human impact on forests,[4] global agricultural field-size data[5] and more.

Land cover validation[edit]

Land cover disagreement
Land cover disagreement over Africa in croplands and forests available for analysis in Geo-wiki

Global land cover validation exercises are feasible as images less than 2.5 meter resolution provide very detailed information on land cover with global coverage of at least 20%[6] with more high-resolution, up to date images continuously being added. Internet tools such as Google Earth offer enormous potential for land cover validation.[7] The use of Volunteer Geographic Information for land cover validation studies seems even more relevant as Google Earth has been used for the recent validation of remote sensing derived products e.g., the European forest cover map[8] as well as the latest global land cover map GlobCover.[9] Google Earth allows wider audience to be involved in a validation exercise.

Applications of Geo-Wiki go beyond simply improving land cover. An application helps to predict future deforestation in Central Africa,[10] combining five existing cropland data sets from sub-Saharan Africa to create a new map which has higher accuracy than existing maps. This should reduce uncertainty and improve predictions in land use, vegetation, climate change, and earth systems modeling. Scientists from several research institutions describe development of the map in Geophysical Research Letters, along with the application of Geo-Wiki.[11]


The Geo-Wiki ecosystem comprises a number of applications, some of which use gamification mechanisms to attract and motivate citizen scientists and experts to participate in campaigns and make valuable contributions to science.


  1. ^ Fritz, Steffen; McCallum, Ian; Schill, Christian; Perger, Christoph; Grillmayer, Roland; Achard, Frédéric; Kraxner, Florian; Obersteiner, Michael (2009). "Geo-Wiki.Org: The Use of Crowdsourcing to Improve Global Land Cover". Remote Sensing. 1 (3): 345–354. Bibcode:2009RemS....1..345F. doi:10.3390/rs1030345.
  2. ^ See, Linda; Mooney, Peter; Foody, Giles; Bastin, Lucy; Comber, Alexis; Estima, Jacinto; Fritz, Steffen; Kerle, Norman; Jiang, Bin; Laakso, Mari; Liu, Hai-Ying; Milčinski, Grega; Nikšič, Matej; Painho, Marco; Pődör, Andrea; Olteanu-Raimond, Ana-Maria; Rutzinger, Martin (2016). "Crowdsourcing, Citizen Science or Volunteered Geographic Information? The Current State of Crowdsourced Geographic Information". ISPRS International Journal of Geo-Information. 5 (5): 55. Bibcode:2016IJGI....5...55S. doi:10.3390/ijgi5050055.
  3. ^ Vohland, Katrin; Land-zandstra, Anne; Ceccaroni, Luigi; Lemmens, Rob; Perelló, Josep; Ponti, Marisa; Samson, Roeland; Wagenknecht, Katherin, eds. (2021). The Science of Citizen Science. Springer International Publishing. doi:10.1007/978-3-030-58278-4. ISBN 978-3-030-58277-7.
  4. ^ "New Citizen Science Campaign on Human Impact on Forests - 2019 - IIASA". Retrieved 2020-11-05.
  5. ^ "Crowdsourced field data shows importance of smallholder farms to global food production - 2018 - IIASA". Retrieved 2020-11-05.
  6. ^ Potere, David (2008). "Horizontal Positional Accuracy of Google Earth's High-Resolution Imagery Archive". Sensors. 8 (12): 7973–7981. Bibcode:2008Senso...8.7973P. doi:10.3390/s8127973. PMC 3791001. PMID 27873970.
  7. ^ Butler, Declan (2006). "The web-wide world". Nature. 439 (7078): 776–778. doi:10.1038/439776a. PMID 16482123. S2CID 4406719.
  8. ^ Pekkarinen, Anssi; Reithmaier, Lucia; Strobl, Peter (2009). "Pan-European forest/Non-forest mapping with Landsat ETM+ and CORINE Land Cover 2000 data". ISPRS Journal of Photogrammetry and Remote Sensing. 64 (2): 171–183. Bibcode:2009JPRS...64..171P. doi:10.1016/j.isprsjprs.2008.09.004.
  9. ^ Defourny, P.P.; Schouten, L.; Bartalev, S.; Bontemps, S.P.; Caccetta, P. et al., Accuracy Assessment of a 300 m Global Land Cover Map: The GlobCover Experience, January 2009, via, abstract accessed 27 October 2023
  10. ^ Nayar, Anjali (2009). "Model predicts future deforestation". Nature. doi:10.1038/news.2009.1100.
  11. ^ Fritz, Steffen; You, Liangzhi; Bun, Andriy; See, Linda; McCallum, Ian; Schill, Christian; Perger, Christoph; Liu, Junguo; Hansen, Matt; Obersteiner, Michael (2011). "Cropland for sub-Saharan Africa: A synergistic approach using five land cover data sets". Geophysical Research Letters. 38 (4): n/a. Bibcode:2011GeoRL..38.4404F. doi:10.1029/2010GL046213.

External links[edit]