A quadtree approach based on European geographic grids: reconciling data privacy and accuracy

Abstract

Methods to preserve confidentiality when publishing geographic information conflict with the need to publish accurate data. The goal of this paper is to create a European geographic grid frame- work to disseminate statistical data over maps. We propose a methodology based on quadtree hierarchical geographic data structures. We create a varying size grid adapted to local area densi- ties. High populated zones are disaggregated in small squares to allow dissemination of accurate data. Alternatively, information on low populated zones is published in big squares to avoid iden- tification of individual data. The methodology has been applied to the 2014 population register data in Catalonia.