Mapping Cropland in Ethiopia Using Crowdsourcing

Linda See, Ian McCallum, Steffen Fritz, Christoph Perger, Florian Kraxner, Michael Obersteiner, Ujjal Deka Baruah, Nitashree Mili, Nripen Ram Kalita

Centre for Geographical Studies, Dibrugarh University, Dibrugarh, India.
Department of Geography, B. Borooah College, Guwahati, India.
Department of Geography, Gauhati University, Guwahati, India.
Ecosystems Services and Management Program, International Institute for Applied Systems Analysis, Laxenburg, Austria.

DOI: 10.4236/ijg.2013.46A1002                

Abstract

The spatial distribution of cropland is an important input to many applications including food security monitoring and economic land use modeling. Global land cover maps derived from remote sensing are one source of cropland but they are currently not accurate enough in the cropland domain to meet the needs of the user community. Moreover, when compared with one another, these land cover products show large areas of spatial disagreement, which makes the choice very difficult regarding which land cover product to use. This paper takes an entirely different approach to mapping cropland, using crowdsourcing of Google Earth imagery via tools in Geo-Wiki. Using sample data generated by a crowdsourcing campaign for the collection of the degree of cultivation and settlement in Ethiopia, a cropland map was created using simple inverse distance weighted interpolation. The map was validated using data from the GOFC-GOLD validation portal and an independent crowdsourced dataset from Geo-Wiki. The results show that the crowdsourced cropland map for Ethiopia has a higher overall accuracy than the individual global land cover products for this country. Such an approach has great potential for mapping cropland in other countries where such data do not currently exist. Not only is the approach inexpensive but the data can be collected over a very short period of time using an existing network of volunteers.

Keywords

Cropland Mapping; Crowdsourcing; Interpolation; Validation

Conflicts of Interest

The authors declare no conflicts of interest.

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