Rules And Standards for Spatial Data Quality in GIS Environments

In the last thirty years the need to associate geographical data to quality specifications has become particularly evident. Digital spatial data of different origins and quality are usually integrated in GIS environments, by determining an indefinite level of global accuracy in such systems. Moreover, the introduction of GIS in the mapping process has produced a completely new type of user different from the traditional map user. This situation requires the identification of shared requirements for a rational and accurate implementation of such systems. It is necessary to define parameters and data transferring modalities in order to share the same data among different users without losing information: parameters and modalities become essential in the definition of a transfer or exchange standard. With a standard it is possible to maintain open systems and extensible applications, and also to allow public and private agencies to make the use and the production of digital data optimal. The problem is the choice or the definition of international standards that have to acknowledge the needs and the interests of data users, developers and providers. In this paper the quality approaches in GIS contexts and some of most meaningful standards are examined. This is the starting point to face spatial data quality problems in GIS environments. In fact, since users determine quality according to their multidisciplinary information needs, other factors, such as compliance to specific needs and availability of rules and quality control tools integrated in such systems, etc., must be considered