GeographicFeature: broaden definition so as not to require 'natural (i.e. not human made)'

[jonathanvajda]

It seems false that every GeographicFeature must be a natural. There can be human-made hills, canyons, rivers, etc. If so, the GeographicFeature should not require all instances to be natural in the definition.

Definition (bold is my emphasis)

• "An Environmental Feature that is a natural (i.e. not human made) topographical feature having a (relatively) stable location in some Geospatial Region which can be designated by location-specific data."

Subclasses of GeographicFeature include subclasses of HydrographicFeature, such as rivers, lakes, etc. But these also can be human-made, such as the lake created by a dam (i.e. impoundment; e.g., Lake Ray Hubbard outside of Dallas, Texas) or a river created out of other waterways that may not necessarily be rivers (canals, channels, etc.; e.g., Chicago River).

Alternatively, we would need to reproduce the hierarchy of GeographicFeature's hierarchy under cco:Artifact, as cco:AnthropogenicHill, cco:AnthropogenicLake, cco:AnthropogenicRiver, etc. This seems to me to be a non-ideal design pattern. Moreover, it seems possible that some environmental features are caused by humans, but it is not clear whether it is human-made or natural, since some permanent environmental features are byproducts of human actions (e.g., perhaps human-caused climate change; construction projects that alter water tables or cause permanent pooling of water.