WaterBody concept

[mbeaufils]

This concept is well defined by HydroDWG and GeoScienceDWG. I would recommend in this CityGML Conceptual model to reuse the definition provided by WaterML2 Part 3 : Hy_Features : https://docs.opengeospatial.org/is/14-111r6/14-111r6.html#_the_hy_features_conceptual_model (or at least take position against that definition, if the concepts are different).

It will be helpful for interoperability between CityGML and WaterML2.

Water Body (as defined by WaterML2 Part3):
The HY_WaterBody feature type specializes the general HY_HydroFeature class. A waterbody is part of the hydrographic network and is either standing in a depression or flowing in a channel, which are parts of the channel network. A waterbody may be segmented in vertical sections at right angles to the main (average) direction of flow or along its centerline, and horizontal strata. Conceptually, each waterbody, or a stratum, could be thought of as a reservoir used for storage, regulation or control of water recourses.

[3DXScape]

Suggested to write an example of how CityGML representation and WaterML2 representation could interoperate - send to mbeaufils?

[mbeaufils]

Here is the EA uml of HY_Features : http://docs.opengeospatial.org/is/14-111r6/uml/
As well as a JSON-LD instance of Hy:WaterBody : https://opengeospatial.github.io/ELFIE/FR/HY-WaterBody/sgwi/E6390700

Looking at the WaterBody ADE definition from CityGML ("The WaterBody module supports representation of the thematic aspects and 3D geometry of rivers, canals, lakes, and basins."), I would say the WaterBody ADE is not only about waterbody, but hydrography. It would connect to more than the Hy_Features:WaterBody concept.

[3DXScape]

Resolution: add explanation of this issue and possibly suggestions for interoperability to Users Guide.
Regarding the comment: the CityGML waterbody includes all sorts of water bodies, not just those in the domain of hydrography. This needs to be clear in the Users Guide.