1

Hello. I want to download all coastline data to my machine. I think this is going to be about 20Gb of data. An overpass query is presumably not the right approach.
Please could someone give me some guidance on a suitable approach?
Kind regards, Chris

2

Hi

Check Coastline - OpenStreetMap Wiki which leads to Coastlines.

Is that what you are looking for?

3

Hi, no. Iā€™m after the basic OSM coastline data in XML format. So Iā€™ve downloaded all UK area coastline data before using a query something like:

area[ā€œISO3166-1ā€=ā€œGBā€];

(

way"natural"=ā€œcoastlineā€;

node(w);

);

out;

Iā€™ve then done my own postprocessing to get this into a SQLite database in the format I want. I now want to extend this to the entire world. What would be the right way to download such a large data set?

Iā€™m blind and typically most GUI tools arenā€™t accessible with a screen reader so Iā€™m unable to import Shapefiles. And currently I also want to do my own processing to get the data into my SQLite database.

Best, Chris

4

Iā€™ve never done anything this low level, but would a software library like GDAL be able to get the ā€œnormalā€ coastline ShapeFiles into a suitable SQLite database without a GUI? I think at its most basic it exists mostly as a set of command line tools.

Do you need additional information that the ShapeFiles just donā€™t have?

I donā€™t have a firm grasp on how big a set of all the coastlines is in one of the native OSM formats. The limit on the ā€œmainā€ Overpass instance is 1GB/day. Iā€™m not sure if it could even handle that in one go. The recommendation for large amounts of data is usually to download a copy of the planet file (or a regional extract) and run your extract locally using something like osmosis. My gut feeling is that if you can find some way of using the existing coastline extracts thatā€™s probably going to be easiest.

5

Thanks for your reply. I just need all the segments that make up coastlines as my application uses this to determine if my userā€™s position is in the sea or on land.
I hadnnā€™t come across GDAL before so thanks for pointing it out. Your suggested approach sounds sensible. I just have to work out how to use it.
Might still be fun though to try downloading planet data but then Iā€™ll also need to work out how to use Osmosis.
Thanks, Chris