VGI in Cadastre: a Greek experiment to investigate the potential of crowd sourcing techniques in Cadastral Mapping

What make citizens participate in mapping projects? What motivates them to get involved in a non-hierarchical network of individuals who collect, edit and share geospatial data? Would they be willing to participate in cadastral mapping as an alternative way to speed up the cadastral survey and minimise the costs and errors which rise when traditional procedures allow limited owners' participation? The answers are still ambiguous. However, it is a fact that the way geospatial data are used and the way citizens comprehend its importance have changed dramatically during the last years. The paper briefly gives an introduction on the evolution of Neogeography and the citizens' involvement in spatial data collection, editing and uploading on the web, and of the introduction of the term volunteered geographic information (VGI) and its adoption by the scientific community. The paper then presents the first results of an academic research being compiled at NTUA in collaboration with FIG Com3 WG 3.2. focusing on the investigation of the potential for intergrading crowd sourcing techniques to create draft cadastral maps. The application area chosen for the experiment is the rural part of the village 'Tsoukalades', on the Greek island of Lefkada. Fifteen volunteer land owners participated to a weekend experiment and collected geospatial data for the delineation of their land parcel boundaries on a cadastral map; the spatial data were collected with the aid of a handheld GPS after a brief training; the resolutions from the interviews with the land owners and the resulting citizens' cadastral map are presented.