Harnessing the power of citizen science

Land-use change can have far-reaching impacts on issues as broad as flood resilience, food security, air pollution, and biodiversity protection. Monitoring it is therefore crucial, and one effective and cheap way to do it is to engage citizen scientists. In 2016 the IIASA Ecosystems Services and Management Program furthered its pioneering work in citizen science, exploring how to encourage people to take part, assessing the quality of the data, and launching a citizen science observatory.

In 2016, a new IIASA-led project, LandSense, was launched to link remote sensing with citizen-science data collection. The citizen science observatory includes an engagement platform that hosts various services and tools for collecting and sharing data from satellites and citizens. The citizen science campaigns run by the project will help monitor resources in both urban and rural contexts, in select regions of Austria, France, Germany, Spain, Slovenia, and Serbia, as well as beyond Europe in Indonesia.

The concept underpinning the LandSense Citizen Observatory

Citizen science data can play an important role in long-term, accurate monitoring of agricultural production—crucial to policies to increase food security and reduce food price volatility. In 2016, as part of the EU-funded Stimulating Innovation in Global Monitoring of Agriculture project, IIASA researchers helped validate and improve a key map of cropland distribution using its suite of crowdsourcing land cover tools, collectively known as Geo-Wiki.

Two key concerns when using citizen science data for such purposes is the quality of the data and the need to engage a large number of people. The Land Use Cover Area Frame Sample is an EU land-cover and land-use change survey, which takes place every three years. The data needed can be collected by citizens, using the IIASA-developed mobile phone application FotoQuest Austria, for example. However, the quality of the data was in question.

As part of the European Research Council-funded project Crowdland, IIASA researchers compared the data collected by the citizens with those of the professional surveyors. The results showed that both land cover and land use could be crowdsourced with an accuracy of about 80%. This represents a new source of potentially valuable information for the validation of land cover maps, is much cheaper than a professional survey, and has the advantage that the data can be collected continuously over time.

Motivation among citizens, however, is very uneven. Mobile applications that involve user-generated content generally have 90% of the content provided by only 1% of the users. Of those remaining, 9% of users provide content some of the time while 90% use the content but do not contribute anything [1].

Validation data gathered in the SIGMA crowdsourcing campaign

The IIASA Ecosystem Services and Management Program has run three campaigns to increase the percentage of users providing content. For Picture Pile, contribution to the science was the only incentive, but for FotoQuest Austria small prizes were also introduced. For Geo-Wiki, Amazon vouchers and coauthorship on a scientific publication led to rapid uptake by users. Rapid feedback and regular interaction with the participants was also a key part of this campaign and had noticeably positive effects on participation.


[1] Fritz S, See L, & Brovelli M (2017) Motivating and sustaining participation in VGI. In: Mapping and the Citizen Sensor, eds. Foody G, See L, Fritz S, Fonte C, Mooney P, Olteanu-Raimond A, & Antoniou V London: Ubiquity Press.

[2] Waldner F, Fritz S, Di Gregorio A, & Defourny P (2015). Mapping priorities to focus cropland mapping activities: Fitness assessment of existing global, regional and national cropland maps. Remote Sensing 7 (6): 7959-7986.

[3] Waldner F, Fritz S, Di Gregorio A, Plotnikov D, Bartalev S, Kussul N, Gong P, Thenkabail P, et al. (2016). A Unified Cropland Layer at 250 m for Global Agriculture Monitoring. Data 1 (1): e3.

[4] Laso Bayas JC, See L, Fritz S, Sturn T, Perger C, Dürauer M, Karner M, Moorthy I, et al. (2016). Crowdsourcing In-Situ Data on Land Cover and Land Use Using Gamification and Mobile Technology. Remote Sensing 8 (11): e905


The SIGMA project is led by the Belgian company VITO with a consortium of 22 EU and international partners

LandSense is led by IIASA with a consortium of 17 EU partners including 5 research institutes/universities, 5 small medium enterprises, 3 NGOs, 3 government bodies and the European Citizen Science Association, a list of collaborators can be found here.