[Tagging] Drain vs ditch

[Peter Elderson]

Same here. Drains we don't have that much (almost none), but many many
ditches of all sizes ('sloot') and canals of all sizes ('vaart', 'gracht',
'singel').
They carry and store water to and from the land: the whole system is
designed to keep ground water levels fixed in dry times as well as wet
times, no matter how extreme.  So the flow direction is not fixed and the
waterways are used for land drainage, irrigation, fire brigades, drinking
water for cattle, boats and canoes, dumping bodies, murder weapons and
broken bikes, and at times, ice skating. No single dedicated use.
The consequence of mapping all ditches as ways is that in z19 on OSM carto
the land look almost water-less, while in z14 the amount of water looks
much higher than it actually is.



Vr gr Peter Elderson


Op do 24 jan. 2019 om 12:24 schreef Eugene Podshivalov <yaugenka at gmail.com>:

> The question that still remains is: what does "small" and "large" mean?
>
> I daresay there is no way and no need to clarify the meanings of "small"
> and "large" for artificial waterways. We can leave this up to the user to
> decide on it.
> Even the definition of a steam as "you can jump over it" is not really
> observed. You can jump over a 1-1.5 meter waterway but people are tagging 3
> meter wide waterways as steams as well because otherwise there would be a
> big difference between the stream 1-1.5 and river 1.5-10 meter width ranges
> (waterways greater than 10m can already be mapped with waterbodies, so I
> don't mention them there).
>
> In the place where I live drainage ditches and drains can be from 0.1 to 5
> meters wide, and anything greater then that can be called a canal.
>
> Cheers,
> Eugene
>
> вс, 20 янв. 2019 г. в 01:22, Markus <selfishseahorse at gmail.com>:
>
>> On Wed, 16 Jan 2019 at 13:40, Eugene Podshivalov <yaugenka at gmail.com>
>> wrote:
>> >
>> > ditch - Small artificial free flow waterways used for irrigating or
>> draining land as well as for deviding land. Irrigation ditches can be lined
>> or unlined, drainage ditches are usually unlined. Consider using
>> waterway=canal for large irrigation or land drainage channels. Consider
>> using waterway=drain for lined superflous liquid drainage channels.
>>
>> I would even go one step further and abandon waterway=drain.
>>
>> The question that still remains is: what does "small" and "large" mean?
>>
>> Regards
>>
>> Markus
>>
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