[Tagging] intermittent vs seasonal
61sundowner at gmail.com
Sat Oct 3 11:58:25 UTC 2015
On 3/10/2015 6:51 PM, Mateusz Konieczny wrote:
> On Fri, 2 Oct 2015 21:50:56 +1000
> Warin <61sundowner at gmail.com> wrote:
>>>> 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.
> Can you provide sources that in hydrology "intermittent waterway" does
> not apply to regular appearance/disappearance of water?
> According to what I found "intermittent waterway" include not only
> "random" disappearance of water. It explicitly includes
> case of "Intermittent streams flow seasonally".
> "Intermittent streams flow seasonally in response to snowmelt and/or
> elevated groundwater tables resulting from increased periods of
> precipitation and/or decreased evapotranspiration." from "Temporary
> streams" by Margaret Palmer, or
> https://en.wikipedia.org/wiki/Perennial_stream " "Perennial" streams
> are contrasted with "intermittent" streams which normally cease
> flowing for weeks or months each year, and with "ephemeral" channels
> that flow only for hours or days following rainfall." or
> https://en.wikipedia.org/wiki/Stream#Intermittent_and_ephemeral_streams .
The 3 cases are;
Seasonally: flows on a yearly cycle.
Intermittent: flows randomly, no pattern nor season.
Combination - Seasonal and intermittent: Where the flow _may_ only take
palace in one or more (but not the whole year) season/s but does so
randomly within that period.
I think your text is the combination case .. poorly worded but that is
what it is.
Quote - "_Intermittent_ streams flow_seasonally_" - both words used ... In this case use both tags!
If I can make it clearer?
"Intermittent streams flow in response to snowmelt"
In this case the flow is random in response to the snow melt, if the snow is deep enough .. it flows when it melts.
"streams flow seasonally in response to snowmelt"
In this case the flow is seasonal in response to the snow melt.
Combining the two .. both seasonal and intermittent... poorly done and I can see how it is open to misinterpretation..
I think you have taken the quote as a meaning of intermittent.. I don't think that is the case.
Writing a text that is both technically correct, easy to understand and entertaining ... well that is a difficult job!
As I say it is poorly worded, but reading further in, from what is given, I get that
it only happens on snow melt - so only in spring- thus seasonal,
and then only if the snow is deep- so intermittent.
Does that help?
Again: Intermittent does not mean seasonal.
Intermittent does not imply a ratio of wet to dry either.. it may be wet
'typically' once every 3 years. Or dry 'typically' once a week.
If that information is required then at least one new key is needed ...
probably a few of them, typical frequency, typical wet to dry ratio to
PS I have tried to find that book ... not listed on an Australia wide
That is a public search, not research search. As in public libraries
rather than scientific papers.
It should show up if it were in the university libraries though. But
some of them have thrown their books out - to rely on electronic issues.
I have had to purchased a few books I could not get in Australia..
abebooks is good..
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