Why not ask your question on the new OpenStreetMap Community Forum?

The Mississippi River, just to the east of St Louis MO in the USA, is "missing" for part of its length. It appears as land, and an island in the river appears as water. This seems to indicate there is some problem with the relation used for the riverbank, but I can't find it. In addition, there seems to be a second "riverbank" shape on top of the relation (similar but not identical shape). Does anyone know how to debug this? I am new to OSM relations and don't know where to start...

Link: http://www.openstreetmap.org/?lat=38.7232&lon=-90.1832&zoom=13&layers=M

asked 15 Dec '12, 22:40

eric22's gravatar image

eric22
401111322
accept rate: 50%

edited 15 Dec '12, 22:42


You are right, there are several problems here - parts of the river are mapped twice, and one of these duplicates is a very large and broken polygon that includes (or tries to include) a couple of tributaries (among them the Meramec). It is probably hopeless to try and fix this so my suggestion would be to delete that large polygon (or cut it into smaller pieces and re-use those that aren't already covered by something else).

The OSM Inspector is a good tool to check multipolygons polygons for sanity, and it shows this polygon as having un-closed outer rings:

alt text

(Note however that OSM Inspector doesn't have live data - it is usually a day behind, so don't expect the display to change immediately after you've fixed something.)

permanent link

answered 16 Dec '12, 00:14

Frederik%20Ramm's gravatar image

Frederik Ramm ♦
82.4k927201272
accept rate: 23%

Your answer
toggle preview

Follow this question

By Email:

Once you sign in you will be able to subscribe for any updates here

By RSS:

Answers

Answers and Comments

Markdown Basics

  • *italic* or _italic_
  • **bold** or __bold__
  • link:[text](http://url.com/ "title")
  • image?![alt text](/path/img.jpg "title")
  • numbered list: 1. Foo 2. Bar
  • to add a line break simply add two spaces to where you would like the new line to be.
  • basic HTML tags are also supported

Question tags:

×73
×23

question asked: 15 Dec '12, 22:40

question was seen: 3,449 times

last updated: 16 Dec '12, 00:14

powered by OSQA