Building a Crowd-sourcing Tool for the Validation of Urban Extent and Gridded Population Steffen Fritz, Linda See, Ian McCallum, Michael Obersteiner - International Institute of Applied Systems Analysis Christian Schill - University of Freiburg Christoph Perger - University of Applied Sciences Wiener Neustadt

1. Building a Crowd-sourcing Tool for the Validation of Urban Extent and Gridded Population Steffen Fritz, Linda See, Ian McCallum, Christian Schill, ChristophPerger and Michael Obersteiner International Institute of Applied Systems Analysis (IIASA) Austria

2. Importance of global land cover Global land cover is baseline information for a wide variety of application: To delineate ecosystems Inputs to global models of land use and land use change, e.g. Globiom Climate change mitigation policies e.g. REDD Biofuel debate: where is the additional land? Food security

3. Problems with global land cover When different products are compared, there are lots of disagreement between them One might say cropland, another forest Confusing if you are a user – which one is correct? Which is the best product to use? Study by Quaife et al – on veg modelling Disagreement overall and/or spatially

4. Disagreement in Crop/Forest Domains

5. Spatial disagreement

6. Urban areas Rapid urbanisation – led to many problems > 50% of the world’s pop live in cities By 2050, set to increase to 80% Accurate figures needed to estimate resource use, e.g. future carbon emissions, domestic water consumption, infrastructure, housing, etc. Difficult to classify

8. Estimates from different products

9. Disagreement in the urban domain

10. Urban disagreement between GLC-2000 and MODIS

13. geo-wiki.org Crowd-sourcing application to improve land cover

14. Architecture

15. urban.geo-wiki.org

16. Disagreement layers

17. Validation of urban land cover

18. Validation of urban land cover

19. GRUMP population layer

20. Future Developments for urban.geo-wiki.org Building a hybrid map of urban areas – already carried out for the cropland domain Addition of other datasets E.g. Night time luminosity, Open Street Map Ability to validate the population data Addition of a gaming element Change studies through integration of Landsat imagery 30 m land cover map being developed

21. Validation Competition We will be running a competition this summer Email me (see@iiasa.ac.at) or see me afterwards and I will put you on the mailing list Register for urban.geo-wiki.org Validate at least 100 points to qualify Highest number of validations will be awarded a prize

22. Thank you! For further information, please contact us: Steffen Fritz (fritz@iiasa.ac.at) Linda See (see@iiasa.ac.at)