[Talk-in] Extracting rivers as multipolygons

[Arun Ganesh]

On Sat, May 5, 2018 at 7:56 PM, Aruna S <safincrazy at gmail.com> wrote:

> Ramya!
>
> Hi, ok. So, do you have ideas around extracting the relations I've sent as
> an example (https://www.openstreetmap.org/edit#map=16/24.4812/79.8781) -
> for example, if I wanted to extract all relations that make up the Sutlej
> river, would I have to manually find each each relation ID and use the
> above query, or is there a simpler way to extract all the relations and
> multipolygons that compose this river?
>

Ideally, all riverbanks that are part of the river are also added into the
relevant river relation, but i think this mapping is currently incomplete.

A programmatic way to try to do this in turf could be:

   - Extract the way/centerline of the river needed
   - Convert the line into a polygon by creating a buffer around it (20m
   should work)
   - Find all water polygon/relations that intersect with the buffered
   centerlines




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