Relations to define geographic areas such as valleys, mountain ranges, bays, peninsulas.
Most of these have some degree of fuzziness either in their definition or boundaries. Sometimes administrative entities declare "legal boundaries" of geographic features. Local perception or administrative definition of the extent of a single geographic range may differ in neighboring countries.
The geographic range relation should allow the specification of both exact and fuzzy borders and encompass multiple conflicting administrative and geographic boundary definitions.
Sometimes administrative entities declare "legal boundaries" of geographic features.
Typically these range are fractal - a large valley has many small valleys on its side which have smaller child valleys in turn.
- delimited by ridges, cliffs, crests or a bunch of mountain peaks. The ridges and peaks aren't supposed to be part of the valley but nobody can tell how far up-slope the valley goes.
- "valley side" is frequently completely arbitrary
- sometimes additional constraints such as specific places/features implicitly in/excluded by local consensus or administrative definition
- delimited by a stretch of coastline but there is frequent disagreement where exactly this stretch ends.
- ocean-side boundary is mostly fuzzy but may be declared administratively (eg for fishing or boating purposes).
- ocean-side boundary may be delimited by constraints such as "up to" a certain water depth
- sometimes additional information such as "up to", "including" or "excluding" specific islands.
- mountain range
- delimited by rivers, valleys, saddles and "lowlands" but might also be defined by geologic properties.