Island is in blue color as water, why?

General talk
1

Hi,

Please OSM experts, take a look in Illinsaari Island in Finland.

https://www.openstreetmap.org/#map=13/65.3283/25.4112

I wonder why its background color is blue? However, there is a residental area inside?

Thanks !

2

Hi Bandix,

I think the problem is that the outer way is tagged as waterway=riverbank whereas this tag should only be on the relation. Try removing riverbank from the way.

3

Hi TZorn,

Thank you for your prompt reply! I tried your suggestion, does not seem to work. From other sources, I found the same that the island should have an inner relation to the water multipolygon.

I tried a couple other things, but still have not found out the fix.
I am not dare enough to publish my trials, I just make edits in Firefox browser and see the results without pushing save.

I have downloaded the java editor also. My issue is not directly visible there. Will continue finding the way to fix…

4

I think TZorn is right.
Remove waterway=riverbank from https://www.openstreetmap.org/way/150354273 and hopefully the island gets dry again.

5

Bandix, I have now removed the offending key waterway=riverbank from the outer way and the islands have dried up.

The problem was that the island is just tagged with place=islands which is not a physical tag. So the island is not rendered by itself. Instead it is rendered what is lying underneath the hole punched into the relation/multipolygon describing the river. But this multipolygon (which describes the river with its islands) was placed on top of another river only defined by the riverbanks. I removed the river underneath and now the land mass shines through, so to speak. (not sure this is a good explanation but hopefully you understand it).

So in general, whenever one uses a multipolygon (relation) to describe a feature the tags used on the relation should not be repeated on the ways belonging to the relation. Other tags describing something else (e.g. place=island in this case) are good, though.

6

Thank you TZorn for your update! And R0bst3r for the comment.

Seems like you have some background knowledge and practice. In editor history, I can see your changes, but I guess I have to wait some time to get the tiles updated on the web.
There were 3 more smaller Islands on the left from Illinsaari (Niittysaari, Simakka, Kirkkosaari). I hope these will also appear soon,

BTW Illinsaari is the place where I live. I feel important to keep it well updated.

Thank you soo much!