HydroNode features are added at the start and end of every WatercourseLink feature. They can represent the source of a watercourse, the end of a watercourse, a junction along a watercourse, or a change of real- world related attribution.
A feature at the end of one or more WatercourseLink features that indicates either the confluence or two or more watercourses and/or a change in the attribution of the WatercourseLink features.
Nature of the HydroNode.
Attribute name: hydroNodeCategory (GML), hydro_node_category (VectorTiles), hydro_node_category (GeoPackage), formOfNode (Esri shapefile)
Type: HydroNodeCategoryValue
Multiplicity: [1]
The location of the HydroNode.
Attribute name: geometry (GML), Not provided (VectorTiles), Not provided (GeoPackage), Not provided (Esri shapefile)
Type: GM_Point
Multiplicity: [1]
This section describes the two features available in the OS Open Rivers product. The attributes associated with these feature types are listed below along with a brief description of their data properties.
The name of the attribute and what it is describing.
The nature of the attribute, for example, a numeric value or a logical indicator.
Describes how many times this element is expected to be populated in the data. An attribute may be optional or mandatory within the product. These are denoted by:
‘1’ – There must be a value.
‘2’ – There must be two values.
‘n’ – There may be one or more values.
‘0’ – Population is optional.
These values may be used in combination.
Association – An association identifies the relationship between features. These relationships are by reference only and the value will be the identifier of the referenced feature.
The WatercourseLink feature is a generalised representation of the watercourse alignment. WatercourseLink features are split where their real-world related attribution changes or where they meet to form a junction.
A segment that forms part of a watercourse.
Direction of water flow in the segment relative to digitisation of segment geometry.
Attribute name: flowDirection (GML), flow_direction (VectorTiles), flow_direction (GeoPackage), flow (Esri shapefile)
Type: LinkDirectionValue
Multiplicity: [1]
Length of network segment.
Attribute name: length (GML), length (VectorTiles), length (GeoPackage), length (Esri shapefile)
Type: Length
Multiplicity: [1]
The geometry that represents the centreline of the link.
Attribute name: centrelineGeometry (GML), Not provided (VectorTiles), Not provided (GeoPackage), Not provided (Esri shapefile)
Type: GM_Curve
Multiplicity: [1]
Indicator that the centreline geometry of the link is a straight line with no intermediate control points – unless the straight line represents the geography in the resolution of the data set appropriately.
Attribute name: centrelineGeometry (GML), Not provided (VectorTiles), Not provided (GeoPackage), Not provided (Esri shapefile)
Type: Boolean
Multiplicity: [1]
Classification of the type of watercourse that is formed by the WatercourseLink.
Attribute name: form (GML), form (VectorTiles), form (GeoPackage), form (Esri shapefile)
Type: WatercourseFormValue
Multiplicity: [1]
Recognised name assigned to the watercourse.
The language used to define the name shall also be provided as a three-digit ISO 639-2 code ('eng', 'cym' 'gla'). Note 2: Where a watercourse has a name in more than one language, this attribute will be the Welsh or Gaelic version.
Attribute name: watercourseName (GML), watercourse_name (VectorTiles), watercourse_name (GeoPackage), name1 (Esri shapefile)
Type: LocalisedCharacterString
Multiplicity: [0..1]
An alternative name of the main watercourse the link is part of. Note 1: The language used to define the name shall also be provided as a three-digit ISO 639-2 code ('eng', 'cym' 'gla').
Where a watercourse has a name in more than one language, this attribute will be the English version.
Attribute name: watercourseNameAlternative (GML), watercourse_name_alternative (VectorTiles), watercourse_name_alternative (GeoPackage), name2 (Esri shapefile)
Type: LocalisedCharacterString
Multiplicity: [0..1]
The HydroNode coincident with the first vertex for this WatercourseLink.
Attribute name: startNode (GML), Not provided (VectorTiles), start_node (GeoPackage), startNode (Esri shapefile)
Multiplicity: [0..1]
The HydroNode coincident with the last vertex for this WatercourseLink. On very rare occasions, the end HydroNode may be the same instance as the start HydroNode.
Attribute name: endNode (GML), Not provided (VectorTiles), end_node (GeoPackage), endNode (Esri shapefile)
Multiplicity: [0..1]