Slowly getting to a conclusion :-)
On 2/10/2015 7:50 PM, Mateusz Konieczny wrote:
On Fri, 2 Oct 2015 15:14:55 +1000
Warin <61sundow...@gmail.com> wrote:
At the moment the 'intermittent' wiki says;
In Description:/Indicates that waterway or water body is intermittent
(seasonal) /
In Key:intermittent:/Or that a water body (lake) disappears
seasonally./
The use of seasonal here limits it to things that have a yearly cycle.
I would rather remove the 'seasonal' references .. something like
In Description:/Indicates that waterway or water body is
intermittent./
I agree with remove of "seasonal"
One could add the word/irregular/ or/random/ in brackets if
helpfull?
I disagree. Waterway where water is missing with some regularity is
stil intermittent.
And I disagree with your disagreement...
If the waterway is 'typically' seasonal then it is not intermittent but
seasonal.
If something is tagged with seasonal then it 'typically' has water in it .. at least
for one season each year. "Typically'.
If something is tagged with intermittent then it 'typically' cannot be expected to conform to some prediction.
If I go back to Lake Eyre .. I could not say when the next time it would be
full of water .. might be next year , or in 30 years time.
I cannot even say that there would be any water in it next year or next decade.
There is an El Niño event happing in the Pacific Ocean .. and that would give
an indication that rain fall is less likely.
But the water in the India Ocean is warmer than normal ...meaning rainfall is
more likely.
SO the meteorologists are not saying anything with certainty (but they never do
anyway unless it has already happened).
http://www.bom.gov.au/climate/enso/
Not predictable = intermittent.
But intermittent does not imply seasonal to me and at least some
others.
I completely agree. Waterway may be intermittent without making it
seasonal. intermittent=yes do not imply seasonal=yes.
Given the weather does not conform that well to the 'season's ..
I'd be more inclined to leave off the seasonal tag.
It depends on location.
NO. It should depend on the features characteristic. But I think we
agree here.
My "it depends on location" applied to "given the weather does not
conform that well to the 'season's".
Yep. The weather never exactly follows the mean. However OSM maps the 'typical'
rather than the exceptions.
So variations around the 'typical' should not trouble the tagging/map for
weather things.
Prior to April 2014 the wiki for intermittent had no reference to
'seasonal' in its description.
And I would not be against removing them. I am only against restricting
intermittent=yes to random lack of water.
Stream that disappears every summer IMHO should be tagged as
[waterway=stream, intermittent=yes, seasonal=yes].
If it disappears every summer then it is seasonal, not intermittent.
Intermittent does not mean seasonal... and should not be compulsory with it.
In fact the use of the two together implies that for some years/seasons there
may be no flow.
We don't use oneway=yes with access=permissive .. saying that the permission is
only given to travel oneway... that is what the oneway tag says.
Same situation here, the seasonal tag says that it only flows seasonally. No
need to define/use intermittent to say the same thing as the seasonal tag.
In case that using intermittent for "waterway does not have a permanent
flow/waterbody does not have a permanent presence" is clearly bad we
need tag is needed to cover this information.
That tag exists .. it is 'intermittent' as defined before April 2014.
I would say
"/In case of waterways or lakes becoming dry on specific times of
year the key" //seasonal
<http://wiki.openstreetmap.org/wiki/Key:seasonal>=*
<http://wiki.openstreetmap.org/w/index.php?title=Tag:seasonal%3Dyes&action=edit&redlink=1>//.
should be used alone, not with the
key:intermittent.////Example:////waterway=stream////name=sample////seasonal=summer//////The
stream "sample" only flows in the summer season./"
Why? What is reasoning for this?
It is the simplest concise and precise way of tagging it. It 'typically' only
flows in summer.
Looking at the wider wiki too !
http://wiki.openstreetmap.org/wiki/Key:waterway
suggests replacement of
waterway=wadi and waterway=drystream
with
waterway=river or stream
and
intermittent=yes.
The wiki for
waterway=wadi suggests (presently) using intermittent for seasonal!
waterway=drystream ...errr arr yes.. also suggests using intermittent
for seasonal.
Seasonal waterways by definition have no permanent flow. Current
practise is to tag such waterway as intermittent=yes. Is there a really
good reason to invent a new tag to convey this information and
deprecate current meaning of intermittent=yes (that is used over 900k
times, with some data consumers already using it)?
The meaning of 'intermittent' on the wiki was changed in April 2014 ... before
that it had no relationship to seasonal. And was correct!
The change is not a depreciation but a clarification.
To me and some others the use by some in OSM of intermittent is now used
incorrectly. And that should stop.
According to taginfo there are 65,467 uses of intermittent with the tag
seasonal. That is less than 7% of the uses of intermittent.
These are the ones that would need checking, even so .. it is not a huge error.
Simply needs to be clarified.. is it 'typically';
yearly cyclic (seasonal)
random, no relation to seasons (intermittent)
may flow seasonally in a random fashion (both seasonal and intermittent)
Use of 'intermittent' for seasonal is not a great error, and can be corrected
by local mappers over time, if they notice.
But new tagging and new mappers should be able to use the tags correctly
without past practices telling them to incorrectly tag things.
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