OpenStreetMap

Overview

OpenStreetMap (OSM) is a collaborative 'volunteered geographic information' project designed to create a free editable geographic database of the world.  OSM is not an original geographic data source but a repository of registered contributor's inputs from manual surveys, GPS devices, aerial photography and other free sources.  (Read more about OSM at its Wikipedia article.)  OSM has no content or tagging quality control but OSM volunteers tend to be dedicated toward contributing good quality data.

The information in this document is incomplete and suggestions (in the comments box below) are welcomed.

This document describes the following selected sources:

ArcMap basemap

The easiest way to incorporate OSM data with ArcMap is to add the 'OpenStreetMap' basemap layer.  

Open

Click Add data > Add basemap...

Open

Select OpenStreetMap > Add

The resultant basemap

Large scale sample from Venezuela.

The symbolization and content of the ArcGIS OSM layer cannot be changed.  It may be preferable to acquire and use OSM data as a shapefile

OSM raw data downloads

The OSM site allows direct downloads of the raw data in 

OSM shapefile sources

BBBike

Geofabrik

Geofabrik Downloads is a free source of OSM data that can be obtained as shapefiles for most of the world.

The Geofabrik download page offers extracts of each continent, and links to sub-regional extracts.  Most continental extracts are only available in .pbf or .bz2 formats but the the continental pages have sub-regional extracts that are mostly available also as shapefiles.  (Conversion of .pbf files to shapefiles is described below.)  Geofabrik downloads contain all OSM data except each feature's contribution metadata.

Most available Geofabrik extracts were acquired from OSM in the previous two days.  (The download pages document the actual acquisition date.)  This could be critical during a sudden-onset crisis for which contributors make timely updates.

Example Geofabrik download resource options:

Global download page containing extracts and links to continent pages such as:

Central America download page containing .pbf, .bz2, and in most cases shapefile extracts, and links to sub-region pages such as:

Jamaica download page containing .pbf and shapefile extracts

Some locations are not available in sub-regional extracts.  For instance, Bermuda is only available as part of the North America extract - and only as a .bpf or .bz2 file.

Using Geofabrik data

Geofabrik extract documentation.  (This link contains the file version number.  If it is broken due to a new version, please inform FIS in the comments below.)

ArcMap

• point features

  • places

  • points of interest

  • pofw_a

  • pofw_a

  • buildings

  • landuse

  • natural_a

  • places_a

  • places

  • pofw

  • railways

  • roads

  • traffic_a

  • traffic

  • transport_a

  • transport

  • water

  • waterways

Geofabrik .pbf extracts opened with QGIS deliver 'lines', 'multilinestrings', 'multipolygons', 'other_relations', and 'points' layers.  These can be exported to shapefiles with topologically unstructured overlapping features.  The 'multipolygons' layer, for instance, has fields like 'aeroway', 'boundary' and 'natural'.  Features are tagged in one or more of these fields so 'natural', for instance, can contain features tagged as 'water', 'beach', 'coastline', among others.  A water polygon layer could therefore be created from the 'multipolygons' layer of the .pbf file with a filter or definition query for 'natural' = 'water'.

Geofabrik extracts that are not available as shapefiles can be imported into QGIS for subsequent use and / or conversion.  But if a Geofabrik extract is available as a shapefile it may be an easier and and more reliable way of preparing the desired features.  

Geofabrik shapefile 'multpolygons' extract filtered for 'natural' = 'water'

Geofabrik shapefile 'multilinestrings'.  Note that only some of the water polygon edges seem to be included as a 'multilinestring'.

extract filtered for 'natural' = 'water'

The line features marking the lake with an island (clearly visible in the ArcMap basemap rendering) is has no tags in the 'waterway' or any other field.

Nevertheless the Geofabrik 

Other OSM shapefile sources

Links to others are available here on the OSM website.  

Outputs/Resources

osmdata

osmdata Jamaica water_polygons

osmdata Jamaica land_polygons

osmdata Saint Lucia lines

Links

• OpenStreetMap

• Geofabrik Downloads

• Geofabrik extract documentation

• QGIS