Hi all,
While reviewing peaks data in Northern Thailand, I came across two areas where recent changesets have introduced large numbers of problematic natural=peak nodes. These include spot height grids on slopes and chains of nodes along ridgelines with no distinct summit. I’m planning a cleanup and wanted to propose some guidelines before proceeding.
Affected areas:
• in Chiang Rai: https://www.openstreetmap.org/changeset/147179207
• in Uttaradit: https://www.openstreetmap.org/changeset/151631891
This is not intended as criticism of the authors of these changesets, but rather an effort to establish clearer guidelines and improve overall data quality.
Mapping every local maximum, shoulder, or minor hill visible in SRTM or similar datasets tends to introduce noise, reduces the usefulness of the data for map users, and makes it harder to identify truly distinct and locally recognized features.
PROPOSED GUIDELINES (Thailand) — updated
Use natural=peak when:
- The feature is supported by topography: a closed or near-closed contour ring
and a clearly identifiable high point. A slope or ridgeline without a distinct
apex does not qualify. - There is some degree of topographic prominence (~50m in the North/Northeast,
~20m in Central/South as a rule of thumb) - Only one node per summit, placed at the highest point
- The feature is verifiable through at least one independent source:
Wikidata/Wikipedia, field survey, or well-established local knowledge
A name using a regional prefix: ดอย (Doi, North), ภู (Phu, Northeast),
เขา (Khao, Central/South), ควน (Kuan, South), is a strong positive signal
but is not required. Unnamed peaks are acceptable if topography clearly
supports them.
Use natural=hill for เนิน (Noen), ลูกเนิน (Luk Noen), and smaller ควน
with low local relief.
SOURCES
Avoid creating natural=peak features from DEM data alone. A local maximum in SRTM or similar datasets does not by itself establish a distinct, mappable geographic feature. Such data is useful for supporting information (e.g. ele=*) once a feature is otherwise verified.
RTSD topo maps may help confirm the presence of a feature, but cannot be copied directly; names and elevations should come from independent, compatible sources.
Adding wikidata=* and wikipedia=* where available is encouraged, as these provide useful supporting references. The Wikidata Query Service (query.wikidata.org) can be used to explore documented Thai mountains with coordinates independently of OSM.
Download Wikidata peaks dataset prepared with OSM tags: here.
PLANNED CLEANUP
Unless there are objections, I plan to:
• Remove clearly unsupported nodes (e.g. unnamed points on slopes with no topographic support)
• Reduce ridgeline clusters to a single node at the most representative high point
Changeset comments will link back to this discussion.
Draft guidelines will also be proposed on the wiki:
https://wiki.openstreetmap.org/wiki/Thailand/Other_Features
Thanks,
Julien
