OpenStreetMap 開放街圖
I have been shown the error of my ways. So I went back and changed those streams that had been marked as ‘intermittent=dry’ back to ‘=yes’ as per standard usage. If I missed any, let me know.
It was also pointed out that I could use ‘waterway=wadi’ but this does not symbolize, and only shows up as a black line. Thus I hesitate to use this combination. But, in much of eastern Sierra County, this would be appropriate. Any thoughts?
It would be nice if OSM would use a dashed line when streams are marked as ‘intermittent=yes’ because it looks a little strange to have all these solid blue lines out here in the desert.
When I made maps for Dept of Defense, we categorized drainage with three levels of flow regime: perennial, intermittent and ephemeral. This is because the dry streams (wadi, wash, arroyo) have distinctly different physical characteristics than intermittent streams.
BTW: I finally got smart and used the map function to nail down my location. :)
討論
由 4rch 於 2014年08月12日 05時54分 發表的評論
osm.wiki/Tag:waterway%3Dwadi osm.wiki/Tagging_for_the_renderer “The basic good practice principle is that you avoid using incorrect tags, or otherwise skewing the data you enter, to make things show up in a specific way on the map rendering.”
https://github.com/gravitystorm/openstreetmap-carto/issues/805
由 imagico 於 2014年08月12日 10時15分 發表的評論
A more fine grained characterization of intermittent waterways makes only limited sense since it can rarely be expected from the mapper to know how frequently a stream carries water. You could add ephemeral=yes in addition to intermittent=yes if you have this information. Also you could have intermittent=yes and seasonal=no to indicate there is no seasonal pattern.
Generally the characterization ‘ephemeral’ is often extremely vague - it can mean anything from ‘frequent but short presence of water for example after rain’ to ‘no water for decades and possibly permanently dry due to climate change’.
由 Sanderd17 於 2014年08月12日 12時37分 發表的評論
As you’re supposed to map regions you know (and don’t do armchair mapping, except in some cases), a mapper can be expected to know how often there’s water streaming there.
But as there are not a lot of populated places where streams are often dry, these tags aren’t used very often.
If you know good worldwide definitions for all sorts of intermittent streams, with re-use of, or coherence with existing tags , I can only suggest you make a proposal. ( osm.wiki/Proposed_features )