Fortaleza/PMF Buildings Import

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Proposal Work Plan Data Conversion Import Guide Corrections Progress

Buildings Import describes a proposal being developed to import data provided by the Fortaleza in Maps platform of the Fortaleza City Council in Brazil. If you want to participate actively go to the import guide. If you want to know all the details of the proposal, read on.

It is important to note that this import is semi-automated, due to the nature of the available data, that is, it is not possible to import the data all at once. This requires a higher user experience, taking more time to perform the import and the necessary adjustments for OSM upload.

Goal

This project aims to manually conflate buildings imported from the Fortaleza in Maps platform provided by city council.

Schedule

  1. April and May 2020: Preparation of the import proposal in the wiki, discussion in the OSM Ceará Telegram group and data testing and validation.
  2. May 2020: Disclosure in talk-br list (in Portuguese) and submission of the import proposal to the Imports List.
  3. May 2020: Annotation in the Import Catalog and add Fortaleza City Council in the contributors list.
  4. May 2020: Import beginning
  5. future: Import ending

Data to import

Data description

The data is provided by the Fortaleza City Council, through its open data platform called Fortaleza in Maps. The data comes from an aerophotogrammetric survey carried out in July 2010, being then a little outdated, and it is in SHP format. The data contains only the geometry information of the buildings and their height.

Data source

The data can be accessed on the Fortaleza in Maps platform (in Portuguese), through the following procedure:

  • You must initially select any data in the panel located on the left side;
  • After the data is loaded on the screen, click on Downloads - Shape and;
  • Remove "Shape do Mapa.shp" (Map Shape) selection and select "Edificações de Fortaleza.shp" (Fortaleza Buildings), proceeding with the download.

License of access and use

The City Council created the Municipal Open Data Infrastructure of Fortaleza through Decree No. 13,474, of December 23, 2014 (in Portuguese). The Fortaleza in Maps website, also created by the city council on December 28, 2016, "... is accessible to population, being the main target audience professionals linked to the area of urbanism, economics and sociology, public agents and academia. One of the main objectives of the site is to expand access to information. In addition to the visualization of the maps, raw information is also available for download in multiple formats that can serve as an object of research or studies for the production of knowledge.".

For even more clarification, the user System-users-3.svgnarceliodesa (on osm, edits, contrib, heatmap, chngset com.) contacted Iplanfor, the institute responsible for Fortaleza in Maps, and obtained authorization to data usage.

Size of the data set

The downloaded data is compressed in a ZIP file, occupying a space of 92 MB compressed, and 334 MB after decompression. According to QGIS, the file has 1,210,876 polygons.

Data conflation

This is the strategy to avoid conflicts with existing data:

  • If possible, you should perform a first filtering in QGIS, observing buildings already mapped in the OSM, and then remove those buildings from those provided by the city council. If not possible, a manual check is mandatory.
  • In principle, the buildings that are already mapped in the OSM must remain, as recommended. Eventually, if they are in significant disagreement, they can be complemented by those from the city council layer, maintaining the OSM tagging data. The total replacement comes as a last case, to not lose the history of the previous building in the OSM.

Data import

A more detailed tutorial is available on the Import Guide tab.

However, given that there may be problems with imported data that require manual intervention, a manual import is planned with a review of each object to be imported.

Work plan

The volume of data to be imported is very large. Therefore, it is proposed to carry out the work by regions, starting from the smallest to the largest. It is thought to carry out the division by neighborhoods, using the number of buildings as a parameter. In larger neighborhoods, work can be divided into blocks, if it is of interest to the volunteers. More details are shown in the Work Plan tab.

Regression plan

If necessary, the changes will be undone using the JOSM/Plugins/Reverter plugin.

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