Additional rules for spatial object types 45

9.4.2.1 Spatial object types draw definitions from the INSPIRE Feature Concept Dictionary

Register

Requirement 11 Every spatial object type specified in an INSPIRE application schema shall be drawn from feature type concepts in the INSPIRE Feature Concept Dictionary Register with status “valid” or proposed as a new register item when no adequate spatial object type already exists.

Requirement 12 If no related concept exists in the INSPIRE Feature Concept Dictionary Register, that can be reused or amended, a concept from another international feature concept dictionary or feature catalogue shall be reused and proposed for adoption in the INSPIRE Feature Concept Dictionary Register, if possible.

In other words, whenever possible, a concept in an INSPIRE application schema shall be drawn from an established dictionary.

EXAMPLE An example for such an established dictionary is the DFDD (DGIWG Feature Data Dictionary), see https://www.dgiwg.org/FAD/registers.jsp?register=DFDD.

The process of defining spatial object types is specified in the methodology for developing data specification (document D2.6) in more detail. In short, the process is as follows: A relevant concept within a theme for a spatial object type is identified. The INSPIRE Feature Concept Dictionary Register is analysed to identify if the concept or a similar concept already exists. The further steps depend on the outcome of this analysis:

a) If it does not exist, the spatial object type is added to the INSPIRE Feature Concept Dictionary Register and used in the application schema. If possible, the new concept is imported from another international feature concept dictionary or feature catalogue.

Importing and referencing existing definitions from an externally managed dictionary once (during the creation of an application schema) obviously would not assure that consistency between the different dictionaries is maintained over time and will require additional organisational measures by the European Commission.

b) If the same concept already exists, the other INSPIRE application schemas are analysed to identify, where the relevant spatial object type is already used. Depending on the result of the analysis

o a new spatial object type may be created in the application schema using the concept from the common feature concept dictionary,

o a spatial object type specified in another application schema may be amended to meet the current requirements and used in the current application schema, or

o a new spatial object type may be specified as a specialisation or generalisation of a spatial object type specified in another application schema.

If a similar concept exists it needs to be decided, if the concepts should be merged – amendments to other application schemas will in general be required – or if they should be treated as separate concepts. Depending on the outcome either a) or b) applies from then on.

9.4.2.2 Spatial object types conform to ISO 19109

Requirement 13 Spatial object types shall be modelled according to ISO 19109 7.1-7.2, 8.1, 8.5- 8.9 and according to the additional rules in Clauses 9-12, 18, and 22 of this document.

NOTE ISO 19109 7.1 and 7.2 describe principles for defining spatial objects and their relationship with application schemas. ISO 19109 8.1 specifies core aspects of the process of modelling application schemas. ISO 19109 8.5 to 8.9 specify the rules for the use of metadata, temporal and spatial characteristics, geographic identifiers as well as the relationship to feature catalogues.

Details on the process of modelling spatial object types in INSPIRE application schemas are provided in document D2.6.

9.4.2.3 Multiple spatial objects may represent the same real-world phenomena

The same real-world phenomenon may be represented by multiple spatial objects (with different unique object identifiers, see below). In general, references between these spatial objects will only exist, if they are explicitly modelled as part of the thematic INSPIRE application schemas.

Recommendation 2 To allow that multiple spatial objects representing the same real-world

phenomenon but in data sets of different Member States can be explicitly associated, an association to other spatial objects of the same type in an adjacent spatial data set should be modelled in the INSPIRE application schema.

NOTE In general, such links will not be available today in most data sets. However, in the process of harmonising the geography of spatial objects representing the same real-world phenomenon that spans the frontier between two or more Member States - see Article 10(2) of the Directive, such mutual references may be added to the source data sets in the Member States.

EXAMPLE The river Danube runs through several Member States. If requirements to aggregate spatial objects of phenomena that span frontiers exist, the association could be modelled as shown in Figure 8 with an association (here called “neighbour”) to other River instances in other data sets. Note that although the association is symmetric (if A is a neighbour to B, then B is also a neighbour to A) it is modelled as an unidirectional association so that the property is called “neighbour” in all River instances.

Figure 8 – Associating multiple spatial objects representing the same river

Requirements to aggregate spatial objects of phenomena that span frontiers exist in environmental community policies. For example, specific reporting requirements or actions may depend on the size of a lake and while no part of a lake that spans multiple Member States may be above the threshold in a single Member State, the size of the lake itself may be above the threshold.