OpenStreetMap Forum

DaveWaterworth

Member

Registered: 2013-08-09

Posts: 11

No water in bays

Hi,

I've noticed a couple of large areas of Sydney Harbor such as here and here where bays don't render properly on the Cycle Map layer. The bays have been defined as a polygon with natural=bay tag and whilst the standard layer shows them as blue the Cycle Map shows white. Is this a problem with the map data?

Regards
Dave

rayquaza

Member

From: DE-BW

Registered: 2012-11-18

Posts: 2,007

Re: No water in bays

That seems to be a problem with the rendering style, not the map data. So maybe you want to notify Andy Alan from http://opencyclemap.org/ so he can correct this.

misabrzi

Member

From: Serbia

Registered: 2012-02-10

Posts: 136

Website

Re: No water in bays

It's not only opencyclemap. Transport map and MapQest open have same problem.

DaveWaterworth

Member

Registered: 2013-08-09

Posts: 11

Re: No water in bays

So basically only OSM seems to understand this way of tagging bays? I've sent a message to Andy but he's on holiday at the moment.

misabrzi

Member

From: Serbia

Registered: 2012-02-10

Posts: 136

Website

Re: No water in bays

Hmm, I'm surprised nobody noticed this earlier.

Vclaw

Member

From: Alba

Registered: 2009-02-25

Posts: 522

Website

Re: No water in bays

Hmm, I'm surprised nobody noticed this earlier.

Not many bays mapped as areas, most are just mapped as nodes.

I think there is a problem with the tagging. A bay should be part of a larger area of water, so it should be part of an area mapped with natural=coastline or natural=water. But the same ways can't be tagged as natural=bay as well as natural=water/natural=coastline. They bay could be mapped with an overlapping way, or a multipolygon.

The wiki page is not veryclear about the correct tagging. http://wiki.openstreetmap.org/wiki/Tag:natural%3Dbay
There is some comments on the talk page about this. http://wiki.openstreetmap.org/wiki/Talk … ural%3Dbay

DaveWaterworth

Member

Registered: 2013-08-09

Posts: 11

Re: No water in bays

I tend to agree, I found a definition of Sydney Harbour which states that the boundary includes the tidal bays (these are defn tidal). As mapped I think the Harbour is a separate way to the bays.

www.austlii.edu.au/au/legis/nsw/num_reg/pcawmr19971997383598.pdf

The boundaries of Sydney Harbour are defined in the Ports Corporatisation and Waterways
Management Regulation 1997. These are waters of Sydney Harbour and of all tidal bays, rivers
and their tributaries connected or leading thereto bounded by mean high water mark together
with that part of the South Pacific Ocean below mean high water mark enclosed by the arc of a
circle of radius 4 sea miles having as its centre the navigation light at Hornby Lighthouse, South
Head.

What's confusing is the way each port boundary is defined in terms of itself and all bays. So there's seems to be an area inside the Sydney Harbour waterway also called Sydney Harbour which is the actual shipping zone?

Vclaw

Member

From: Alba

Registered: 2009-02-25

Posts: 522

Website

Re: No water in bays

If the area is tidal, then it should all be tagged with natural=coastline.
See http://wiki.openstreetmap.org/wiki/Tag: … Dcoastline
It says "The natural=coastline tag is used to mark the mean high water spring line along the coastline at the edge of the sea."

You can then map the bays with overlapping ways or a multipolyon, tagged as natural=bay

DaveWaterworth

Member

Registered: 2013-08-09

Posts: 11

Re: No water in bays

If the area is tidal, then it should all be tagged with natural=coastline.
See http://wiki.openstreetmap.org/wiki/Tag: … Dcoastline
It says "The natural=coastline tag is used to mark the mean high water spring line along the coastline at the edge of the sea."

You can then map the bays with overlapping ways or a multipolyon, tagged as natural=bay

I started to add natural=coastline, but other than a few Islands I couldn't find this tag in use around the Harbour at all so I thought it best to stop as I wasn't sure what the end result would be of having a partial coastline way. User Ciprol has made some changes, waiting for the map tiles to update to see the affect. The change appears to be to set natural=water and water=river. However this isn't a river so whilst that may fix the rendering it doesn't seem the right way of doing things?

Last edited by DaveWaterworth (2013-08-15 23:40:22)

Chip satışı

Member

From: Turkey

Registered: 2013-09-04

Posts: 1

Website

Re: No water in bays

Thank you, I started to add natural=coastline .