ADMINISTRATIVE UNITS INSPIRE KEN WORKSHOP TRANSFORMATION OF THEMES AD, AU, BU, CP AND GN April 2015 ign.

Transcription

1 ADMINISTRATIVE UNITS INSPIRE KEN WORKSHOP TRANSFORMATION OF THEMES AD, AU, BU, CP AND GN April 201 ign.fr

2 Plan Source data Transformation choices and issues Conclusions

3 Source data Some discussions: theme AU is present in 14 of our (internal or external) products Choice for «reference» data BD Parcellaire: more accurate, not edge-matched, depends also on Cadastre BD UNI: whole coverage, depends only on IGN, clean topology BD UNI GE : Large scale topographic data base (around 10K) 2D data for AU CRS : Lambert_93 (national projection based on datum ETRS89) Master Level 1 Update : Production : continuous update (with Statistical Institute as main partner) Delivery : releases every 6 months

4 TRANSFORMATION ISSUES

5 Administrative pyramid: matching levels 6 levels in INSPIRE

6 Administrative pyramid: matching levels Etat Région Département Arrondissement 1 ts Level 2 nd Level 3 rd Level 4 th Level Issue: 7 levels of AU in IGN data 6 levels of AU in INSPIRE Cleaning : «canton» is not really an AU but used for statistics and elections canton deleted from AU Canton Commune Arrondissement municipal (Paris, Lyon, Marseille) th Level 6 th Level Inconsistencies between LoDs canton in EG products => in ELF Regional or Global canton not in ELF Master level 1 Matching with INSPIRE levels

7 Administrative pyramid: data delivery géometrie nom code Code canton Commune Code arrondissement Nom arrondissement Code arrondissement Nom arrondissement Code région Nom région In source data, a key feature «Commune» Attributes of «commune» Attributes of the upper AU In existing data, IGN provides levels 6 and (commune) and attributes of other levels are carried by commune => it is up to user to build upper levels

8 Administrative pyramid: data delivery Etat Région 1 ts Level 2 nd Level Issue: For large scale data, delivery unit is the département (level 3) Département 3 rd Level Arrondissement 4 th Level Commune Arrondissement municipal th Level 6 th Level Does not look relevant to provide levels 1 and 2 in all predefined data sets Envisaged solution Data sets by department ( 100) with levels 6,, 4, 3 Data set with whole France (levels 1, 2,???)

9 Administrative pyramid: data delivery For large scale data as BD UNI, how big will be the country (level1 AU) or even the regions (level 2)? Size (number of vertices) of objects is an issue (e.g. for WFS)

10 Administrative pyramid: data delivery Potential solution (request for change in INSPIRE) For upper levels AU that may be derived from lower ones, offer choice Provide geometry or Provide association to the lower level

11 Administrative pyramid: making new features géometrie nom code Code canton Commune Code arrondissement Nom arrondissement Code arrondissement Nom arrondissement Code région Nom région In source data, a key feature «Commune» Attributes of «commune» Attributes of the upper AU For INSPIRE, we had to derive the upper AU with their own attributes (including geometry and Inspire identifiers) Different matching rules according to the national level

12 Administrative pyramid: making new features New geometry obtained by merging relevant «communes» Duplicate the AdministrativeUnit matching rules for each level

13 Administrative pyramid: making new features IGN has external identifiers for Commune but not for the upper levels Decision was to use thematic identifier based on SHN for all levels of AU but without the canton code

14 ResidenceOfAuthority In INSPIRE model, an administrative unit may have several «ResidenceOfAuthority» In France, itisthe case for upperlevels - «départements» and «régions» (levels3 and 2) - Préfecture (representation of national government) - Hôtel de département / région (local authority) - country (level 1) - Elysée - Sénat - Assemblée Nationale - Matignon

15 ResidenceOfAuthority Decision: include all residences of authority Discussion: how to distinguish them By extending the data type residenceofauthority Adding attribute «nature» = {préfecture, Elysée,.} By adding the «nature» to the name E.g. LAON (préfecture) LAON = name of the ResidenceOfAuthority Préfecture = nature of the ResidenceOfAuthority Chosen solution (easiest, avoiding national extensions)

16 ResidenceOfAuthority : Geographical Name NamedPlace spellingofname language nativeness source namestatus prononciation grammaticalgender grammaticalnumber FRA endonym BD TOPO other VoidValueReason = unpopulated NamedPlace text script nativeness Ex : LAON (préfecture) Latn (latin) VoidValueReason = unpopulated

17 ResidenceOfAuthority : source data Issue : in source data, the points representing RoA and the Administrative Units are in separate feature types => how to link them? Commune (municipality) Source feature type Localisation Semantic link with AU CHEF-LIEU Fuzzy (built-up area) yes All administrative Units Geometric link is not reliable because several exceptions, specific cases Decision: For all AU (except COMMUNE), use the PAI Specific sheets in matching tables General case: use of geometric queries Exceptions: done manually PAI Accurate (building) For COMMUNE, use the CHEF-LIEU (too many features for interactive work, alternative solution) no Heterogeneous result

18 Administrative Boundaries Limite de commune géométrie identifiant Link to Commune???

19 Administrative boundaries : INSPIRE Identifier LocalId : identifier BD UNI GE Namespace: FR_IGNF_BDUniGE_AdministrativeUnits MET Country Code Producer Code Product Code INSPIRE Schema name Recommandations générales (Modèle Conceptuel Générique INSPIRE) Territory Code (metropol, oversea) versionid : void General rule used for INSPIRE identifiers for all themes (but with some exceptions)

20 Administrative Boundaries Different potential solutions 4 AU level AU level 4 AU level 4 4 AU level AU level Probably best solution for users: - Avoid multiple values on attributes - Clear topologic set of boundaries 4 By geometry => using several geometries But not feasible by IGN: - Need to create new features by merging «communal boundaries» - => impossible to provide inspire identifiers

21 Administrative Boundaries Different potential solutions 4 AU level 4 AU level 4 4 AU level 4 AU level 4 4 AU level For users: - Avoid multiple values on attributes - But not the right topology Might be feasible by IGN: - BD UNI identifiers may be used (with some prefix or suffix to make distinction between the different levels of administrative boundaries) By geometry => duplication of geometries

22 Administrative Boundaries Different potential solutions,4,4,4 AU level AU level,4,4 AU level AU level 4,4,4 AU level,4 For users: - implies to deal with multiple values on attributes (not always easy in GIS) By semantic => multiple values on boundaries For IGN: - Looks the easiest way

23 Limites administratives Technical status is : c Not edge-matched for international boundaries edge-matched for other boundaries The «agreed» status will be given in future by the RPCU project (unique representation of CP)

24 Administrative Boundaries In INSPIRE data model, association between Administrative Boundaries and Administrative Units For all levels of AU Association is mandatory in ELF In source data, only Administrative Boundaries and Administrative Units for level (communes) and 6 Association was quite complex to establish!

25 Administrative Boundaries But reverse association easily done by Geoserver (and deegree?)

26 CONCLUSIONS

27 Status of work Matching table meetings 3 meetings (3 h each) Data transformation Done both by Snowflake (Go Publisher) : difficulties to publish data on WFS IGN (pseudo INSPIRE database on PostGre deegree) Done on test data (3 % of territory) Data delivery Validation : to schema and to source data => many iterations By ELF and to French users (documentation, training of IGN staff in contact with users) Big features (as country) not yet delivered

28 Conclusions Missing data / INSPIRE Temporal aspects versionid (in InspireId) beginlifespanversion endlifespanversion Additional data / INSPIRE Depends on our products In some of them, Population Area Elevation information...

29 Conclusions We began by theme AU because we thought it was easy We were wrong! Main difficulties Source data very different from INSPIRE model Based on COMMUNE (level ) Need to reconstruct the administrative pyramid Complex transformation Matching table too theoric (from source data) Use some order in the transformations (to reuse computed features or attributes) Many specific cases in the French administrative real-world Oversea departments (coding) ResidenceOfAuthority