Landuse mapping in OSM and Urban Atlas: a comparison

Jerry Clough

Details about the talk:
Urban Atlas (UA), a fine grain landuse dataset, compiled on behalf of the European Environment Agencies (EEA), has not received the same degree of interest as CORINE from OSM contributors as an imported source of landuse data. The absence of Urban Atlas data for many cities, together with the lack of imports allows data gathered through traditional OSM mapping techniques to be compared with Urban Atlas. This allowed an investigation of how comparable data gathered through traditional OSM techniques are with an equivalent 'official' dataset.
Assignment of OSM tag groups to Urban Atlas categories proved to be straightforward, with a low degree of ambiguity. Residential categories required complete building coverage and pre-processing of data to determine building density. Generating full Urban Atlas coverage often required some additional mapping of landuse categories. In the main this merely involved improving consistency of OSM mapping, and some error checking and correction. Output from these simulations can be made in Quantum GIS, PostGIS data, Shapefiles and Mapnik-generated raster.
Qualitative comparison between the simulated OSM-generated datasets with Urban Atlas reveal not just missing data in OSM, but also errors in interpretation during the creation of Urban Atlas. Quantitative comparison provides further information about the relative accuracy and utility of OSM data. The implications for mappers and users of OSM data are discussed.
In summary, datasets equivalent in detail and categorisation to Urban Atlas were readily generated from OSM data, and coverage could be extended for conurbations not included in the UA data. The been assumption that national and supranational 'official' datasets are likely to be more comprehensive and accurate than OSM (e.g., CORINE) is not true given that OSM mapping fulfils certain minimum criteria.

Details about the speaker:
Jerry Clough has been interested in maps since the age of 4. He has a professional background in scientific research (Genetics, Computer Science) and business consultancy, and is an enthusiastic amateur naturalist. OSM forms a natural nexus between these diverse interests. Apart from day to day use of OSM data on his GPS, he is interested in using OSM to provide accessible and usable maps for naturalists.

Theme: map