Using OpenStreetMap Data with Open-Source GIS | Markieta | Cartographic Perspectives
For many, free and open-source data and software represents accessibility to otherwise inaccessible geospatial workflows in terms of cost and availability. Commercial data used in geographic information systems (GIS) is available through a relatively small number of merchants or vendors, which produce highly accurate, precise, and detailed information. This is produced, however, at a cost that many small and large businesses, private consultants, and startups cannot afford. Open-source data, such as the volunteer geographic information on OpenStreetMap (OSM), represents a community effort to build one of the best web maps, and subsequently the best GIS database, available for free to the public. OpenStreetMap is a web-based map to which any registered user can submit data. These updates, over time, populate the now extensive web map that is the OpenStreetMap. At the same time, the data that lives on the OpenStreetMap can be downloaded and used inside of a GIS for geospatial analysis, cartographic rendering, and other geo-related tasks.
There are various workflows for extracting and consuming the data that is made available by the OpenStreetMap project. One of these methods is outlined in this tutorial. This tutorial will take Mac OSX users through a typical setup of a local PostgreSQL database, downloading and parsing raw OpenStreetMap data, and querying the database to extract data for use in QGIS, an open-source GIS package. Upon completing this tutorial, users will have hit the ground running, with the ability to run spatial queries—such as locating all the coffee shops within 500 metres of a subway station—or building cartographically pleasing reference map books with data that is of interest to the map reader.
THIS TUTORIAL WILL COVER THE FOLLOWING:
Access and browse an OSM data repositories
Download a subset (often called an “extract”) of the planet.osm data package
Install PostgreSQL (object-relational database system)
Install PostGIS for use with PostgreSQL (spatial database extension for PostgreSQL)
Install and utilize osm2pgsql (converts OSM data for use in the PostgreSQL database)
Install QGIS and its dependencies (GIS package)
Query and add data in QGIS from PostGIS/PostgreSQL