User:WanTan/Howto tagging of waterways in Thailand

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At the moment this is just a collection of personal thoughts that i got with help of the discussion in this Thailand forum thread: HowTo tag khlongs (คลอง)?. If you want to help me to improve this page, please reply in the forum or leave your annotations on the discussion page.

This page would like to act as an easy guide on how to tag waterways in Thailand. Of course most of the questions should be the same in other counries. But because of the large number of waterways in Thailand it is worth to consider tagging them in detail.

For identifying the type of a waterways correctly you should always try to take its name into account, if possible. The name of a waterway is more important and correct than its appearance. The name reflects what people think. The appearance changes, sometimes rather fast. Due to human actions some rivers might look more like canals: more concrete (คอนกรีต) than earth (soil; ดิน). Due to lacking maintenance some canals might look more like rivers.

Nature-made waterways

Some terms used in Thailand for waterways that are made by nature:

Thai: แม่น้ำ (Mae Nam), e.g. แม่น้ำโขง (Mekong)
Thai short form: แม่ (Mae), e.g. แม่โขง (Mekong).
English: big river

Thai: ลำน้ำ (Lam Nam), e.g. ลำน้ำปาว (Pao River)
English: watercourse; river trunk

Thai: ห้วยน้ำ (Huai Nam) (แอ่งที่ขังน้ำซึ่งไหลมาจากภูเขา) (stream from the mountains with deep water)
Thai short form: ห้วย (Huai), e.g. ห้วยบางทราย (Huai Bang Sai)
Thai: ลำธาร (Lam Tarn) (ทางน้ำเล็กที่ไหลจากเขา) (slowly flowing stream from the mountains)
English: stream; brook; creek

(Note: Please add more other terms for "nature-made waterways" here if you know some.)

The tagging for all of these naturally formed waterways depends only on the average width of the waterway.

waterway = river
Naturally formed waterway. Typically wider than 5m. If the waterway is smaller than 5 meters you should consider using "waterway=stream" instead.
OpenStreetMap-Wiki: Tag:waterway=river

waterway = riverbank
If a river is wider than 12m it should be drawn as riverbank.
OpenStreetMap-Wiki: Tag:waterway=riverbank

waterway = stream
Naturally formed waterway. Typically smaller than 2m, but can be used up to 5m (e.g. if the water is not deep and people can walk through it).
OpenStreetMap-Wiki: Tag:waterway=stream

"Man-made waterways"

Some terms used in Thailand for "man-made waterways":

Thai: คลอง (Khlong)
English: canal

(Note: Please add more other terms for "man-made waterways" here if you know some.)

waterway = canal
If the name of the waterway contains the word "Khlong" (Thai: คลอง) or if it looks like a typical canal or khlong we should tag it as "canal".
OpenStreetMap-Wiki: Tag:waterway=canal
Wikipedia-EN: Canal
Wikipedia-TH: คลอง (Khlong)

waterway = ditch
If the waterway is significant smaller than a typical canal (less than 2 meters), chances are good that it is a "ditch". If the ditch does not contain any water most of the time consider using barrier=ditch instead of waterway=ditch.
Wikipedia-EN: Ditch

waterway = drain
If it is made out of concrete (คอนกรีต) or build from other hard materials, it is maybe a "drain". A drain must not nessessarily contain water all the time. In dry seasons it could be dry and only be filled while it is raining! If the width exceeds 3 meters and the drain does contain water most of the time consider using waterway=canal instead of waterway=drain.
OpenStreetMap-Wiki: Tag:waterway=drain

Examples of useful additional keys

  • name - the name of the waterway in thai (e.g. "คลองปลัดเฟรียง")
  • name:th - again, the name of the waterway in thai (e.g. "คลองปลัดเฟรียง")
  • name:en - the name of the waterway in english (e.g. "Klong Palat Priang")
  • width - the average width of the waterway (e.g. "8" meaning 8 meter)
  • depth - the average deepness of the waterway (if known)
  • tunnel - if the water flows underground (e.g. "yes")
  • boat - this could state the access conditions for boats (e.g. "yes" or "permissive")

Rendering of waterways

Some renderers (e.g. Osmarender) already support rendering of the attribute "width", so it is a good idea to add this information to the waterway. This will make sure that the waterways will appear on the maps with a proper thickness.