Dominique Laurent
INSPIRE Expert, Standardisation Unit
French Mapping Agency (IGN)
France

Biography
Dominique Laurent is graduate engineer of the French State in the field of geographic sciences. She joined IGN, the French National Mapping Agency, in 1990.After beginning her career in topography, she worked in IGN consulting unit. For 10 years, she has been involved in INSPIRE, as member of the Drafting Team Data Specifications, as facilitator of Thematic Working Groups on Cadastral Parcels and Buildings, as contributor to many INSPIRE-related projects such as EuroRoads, RISE, Humboldt, ESDIN and now ELF. She is currently chairing the Eurogeographics INSPIRE Knowledge Exchange Nerwork.

Abstract
Challenges and Potential Solutions to Implement Temporal Aspects in INSPIRE Specifications

Most of INSPIRE applications schemas include persistent identifiers, versionning and temporal attributes. In theory, if a data provider manages this kind of information in its native database, this should enable him to supply this information also for INSPIRE data and so users might get incremental updates of INSPIRE data just by querying temporal attributes. However, in practice, two main issues arise. First, the transformation process may impact significantly the temporal aspects; typically persistent identifiers may be lost if the schema transformation required by INSPIRE implies splits or merges of features. In addition, the temporal attributes are not always kept by the transformation process : there may be over-detection of evolutions if a native attribute not used for INSPIRE has changed or in contrary under-detection if the transformation process implies joining tables and so, using attributes of other feature types. The second issue is linked to the concept itself of persistent objects. The Generic Conceptual Model gives some examples of good practice regarding life-cycle rules, but these examples are related to simple cases with single geometry features. And the INSPIRE application schemas include quite more complex modeling patterns, such as features with multiple representation (several geometric attributes), features with indirect geometry (e.g. aggregate features as Road, RailwayLine or properties of theme TransportNetworks) or even features without any geometry as the components of theme Address. The ELF (European Location Framework) project aims at concretely implementing INSPIRE in a coordinated way between Member States. As regards INSPIRE temporal aspects, ELF proposes rules for persistent identifiers to address the following cases in order to deal with the issues mentioned above. These rules concern mainly vector data of the annexes I and II themes. These rules might be considered by the INSPIRE MIF, at least as examples of good practice or perhaps even as recommendations. In addition, the ELF project has developed a change detection tool that compares two releases of same data set and so can ensure persistent identifiers and manage temporal attributes.