1. ign.fr HYDROGRAPHY INSPIRE KEN WORKSHOP TRANSFORMATION OF THEMES TN AND HY dominique.laurent@ign.fr 21-22 October 2014

2. Plan  Source data  Transformation choices and issues  Conclusions

3. Source data  BD CARTHAGE:  Medium scale topographic data base (around 50K)  Rather complex structure (associations, aggregate objects, …)  2D data  A common data base between IGN and Water Authorities  Rich semantic content  Topographic data  “business” data : drainage basins, hydro codification, …  CRS : Lambert_93 (national projection based on datum ETRS89)  A project : BD TOPAGE  Large scale data  Rich semantic content of BD CARTHAGE

4. TRANSFORMATION CHOICES FOR HYDROGRAPHY

5. HydroIdentifier INSPIRE HydroId Attr :ClassificationScheme Attr : localId Attr :namespace National Code hydro (BD CARTHAGE) FR

6. Area - Length Area and length may be computed from the geometry but in which CRS? -Area : choice of LAEA (keeps the area) -Length: keep national projection -no obvious better alternative -avoid to make coordinate transformation (geographic coordinates) before length computation

7. Area - Length LAEA is identified by its EPSG code: 3035 (recognised by PostGre) Warning about computing length in projected coordinates as comment in matching table

8. LocalType LocalisedCharacterString is composed of : -a character string -a reference to a “Locale” describing the string (language, alphabet) IGN is using a provisory registry of “Locales” with only one language described (French)

9. BasinOrder As example, INSPIRE provides well-known, « scientific » ordering schemes

10. BasinOrder  BD CARTHAGE has some hierarchy between DrainageBasins  But no attribute “basinOrder”

11. BasinOrder Decision : derive the attribute basinOrder from the hierarchy of source data. Document the orderScheme by “multilingual” explanations (use of mathematic symbol “<“) No order 1 DrainageBasin because in source data no matching feature with RiverBasin

12. GradeSeparateCrossing In INSPIRE, GradeSeparateCrossing is mainly an association between 2 ordered Links

13. GradeSeparateCrossing

14. (INSPIRE) « Franchissement » (BD CARTHAGE) Navigation logic is provided by semantics (4 associations) Matching is impossible. IGN planar network topology is not conformant to INSPIRE

15. Fictitious water links PhysicalWaters delineationKnown: false HydroNetwork fictitious : true

16. CONCLUSIONS

17. Status of work  Matching table meetings  7 meetings (3 h each)  Big matching tables: PhysicalWaters  Direct correspondences :  240 lines  Data types:  330 lines  Code lists :  80 lines  Data transformation  Done by Snowflake on test areas (2 “départements”)  Some issues to understand (complex) transformation  No checking done yet by IGN Not all of them are filled

18. Results : PhysicalWaters INSPIRE feature typesBD CARTHAGE WatercourseX StandingWaterX DrainageBasinX RiverBasin Rapids FallsX LockX Sluice DamOrWeirX Ford, CrossingX ShoreX Wetland EmbankmentX ShorelineConstruction

19. Results : HydroNetwork INSPIRE feature typesBD CARTHAGE WatercourseLinkSequenceX WatercourseLinkX HydroNodeX WatercourseSeparateCrossing

20. Conclusions: main difficulties  INSPIRE schemas are not really complex … but they are very rich : many feature types  Source and target schemas had different logic  BD CARTHAGE  1 feature type for surface elements (grouping watercourse, standing water, shore, wetland, glacier)  1 feature type for linear elements: watercourse  INSPIRE  1 feature type by nature  StandingWater  Watercourse  Shore  …..  With generic geometry (GM_Primitive)  BD CARTHAGE has complex structure  Several names  Many associations  …..  We had to take care a lot about “unknown” values Matching was not really difficult but long and requiring great care Matching was difficult but mainly due to the complexity of our source data

21. Conclusions  Matching tables have used the “updated” INSPIRE schemas  New features (candidates) added manually  But not taken into account by Snowflake  Huge work but very useful to improve our source product  BD CARTHAGE has been used to fill 3 INSPRE application schemas  PhysicalWaters  HydroNetwork  WaterTransportNetwork Challenge for our new product : make it easily derivable into 3 INSPIRE data models