Assessing the Quality of Cadastral Geodata Administrated by the Municipality of the City of Los Ángeles, Chile
ISBN 978-85-88783-11-9
Authors
1Staub, G.; 2Almendras, F.
1UNIVERSITY OF CONCEPCIÓN Email: gstaub@udec.cl
2UNIVERSITY OF CONCEPCIÓN Email: franciscojalmen@udec.cl
Abstract
Cadastral information is sparsely available in Chile. Only a few municipalities handle relevant information and in such a way that it really is a benefit for the community in terms of urban planning, sustainable development, land management and so on. The municipality of Los Angeles is among the few municipalities that intend to implement a cadastral information system. Almost up to date aerial photographs and vector data of road networks, city blocks, park areas, etc. are already available. Nevertheless, little or almost nothing is known about the quality of this data, as it has never been checked in an appropriate manner using for example spatial statistics. Neither exists a standardized update procedure at regular basis to assure timeliness of the geodata. Therefore, standardized quality assessment is carried out using statistical analysis as well as visual and in-situ comparison of the available geodata. This study reveals that not only positional accuracy is weak; displacements of up to 3 meters were observed. Also attribute accuracy is not sufficient for the implementation of a cadastral information system, as no standardized catalog for geodata description and storage exists. Temporal accuracy, data completeness and logical consistency are well for recently build city blocks and would require only some minor modifications. Nevertheless, in case of city blocks that were built a couple of years ago, in particular temporal accuracy and data completeness are weak. In conclusion, since all the mentioned quality aspects are of importance for future tasks that permit to enhance quality of life, we propose several measures, like e.g. usage of international standards for geodata description and storage, coordinate transformation. Such measures would allow to improve, enrich and to complement the available data, without the necessity to replace all the available information by geodata collection and surveying.