3.2.13. Vegetation schema

The vegetation model specified in Section 3.1.13 is realized by the tables shown in Fig. 3.51 which correspond largely to the UML model.

../../_images/citydb_schema_vegetation_diagram.png — Fig. 3.51 Vegetation database schema

SOLITARY_VEGETAT_OBJECT

The attributes class, function, usage, species, height, trunkDiameter, and crownDiameter describe single vegetation objects. The attribute species is of type gml:CodeList in CityGML that can be referenced to a certain codespace. Therefore, another _CODESPACE column is provided in the SOLITARY_VEGETAT_OBJECT table. Similar to the building table attribute with measure information can optionally be coupled with a reference to the used measuring scale by an additional _UNIT column.

The geometry of the vegetation can either be described explicitly using the attribute LOD4_OTHER_GEOM or LOD4_BREP_ID or implicitly using a foreign key relation the IMPLICIT_GEOMETRY table including a reference point and optionally a transformation matrix (LODx_IMPLICIT_REP_ID, LODx_IMPLICIT_REF_POINT LODx_IMPLICIT_TRANSFORMATION, with 1 ≤ x ≤ 4).

PLANT_COVER

Information on vegetation areas are contained in attributes usage, class, function, and averageHeight. There is also a _UNIT column to specify the scale the averageHeight values are based on. The geometry is restricted to a MultiSurface or (and this is unique for PlantCover features) a MultiSolid, represented respectively by the foreign keys LODx_MULTI_SURFACE_ID (with 1 ≤x ≤ 4) and LODx_MULTI_SOLID_ID which refer to the SURFACE_GEOMETRY table.