Dourados/Projetos/Importações/Árvores
Dourados Trees Import was an import of GeoDourados trees dataset which is a file covering the city of Dourados in Brazil, that consists of more than 94,000 trees. The import was successfully finished.
Goals
This project aims to import the trees available from the GIS platform provided by the Dourados City Council (GeoDourados), while manually conflating existing trees on OSM.
Schedule
- March 2022: Preparation of the import proposal in the wiki, discussion in the OSM Brasil Telegram group and data testing and validation.
- June 2022: Disclosure in talk-br list (in Portuguese) and submission of the import proposal to the Imports List.
- June 2022: Annotation in the Import Catalog.
- June 2022: Import begin
- June 2022: Import end
Import Data
Background
Data source site: https://geodourados.dourados.ms.gov.br/
Type of license: Explicit Permission
Link to permission: https://wiki.openstreetmap.org/wiki/File:Opendata-dourados-ms.jpg
OSM attribution: Prefeitura Municipal de Dourados - GeoDourados
Original File
The data can be obtained on GeoDourados GeoServer, searching for arvores ('trees' in Portuguese).
OSM Data Files
The converted .osm file can be download here.
Import Type
This is a one-time import and JOSM will be used to review and upload the elements into OSM.
Data Preparation
Data Reduction & Simplification
The original file consists of tree data that comes as points, so there is no need of data reduction or simplification.
Tagging Plans
Since the original data has only the location of the trees, the following tag will be used:
Changeset Tags
- source = Prefeitura Municipal de Dourados - GeoDourados
- source:website = https://geodourados.dourados.ms.gov.br/
- source:date = 2022
- comment = Importação semi-automática de árvores municipais de Dourados
- website = https://wiki.openstreetmap.org/wiki/Dourados/Projetos/Importações/Árvores
Data Transformation
The only transformation needed is to convert the tags to OSM tagging standard. That can be done by using QGIS or JOSM.
Data Merge Workflow
Team Approach
Workflow
- Initially the data was evaluated regarding its quality. Based on previous analysis, it is of a high quality regarding completeness.
- Then, the data was checked regarding its positioning. Using QGIS, the trees' position were evaluated against all buildings in the city (data coming from same source). It was not identified any conflict between trees and buildings.
- Data was also checked against water bodies. All water features were download using Overpass Turbo, and then checked on QGIS. No trees in this import fall inside any water=* OSM features.
- Confirmed the quality of data, it must be conflated with existing data (see Conflation plan).
- After conflating all data, it must then be uploaded to JOSM.
- Given the size of the file, JOSM will be done to upload the data. It automatically suggests to use 95 requests to upload all trees, so the OSM servers are not overloaded.
- If necessary, the changes will be undone using the JOSM/Plugins/Reverter plugin.
Conflation
This is the strategy that will be done manually, to avoid conflicts with existing data:
- Initially a filtering must be made in Overpass Turbo, using this script, observing trees that are already mapped in the OSM, and then remove those trees from those provided by the Dourados City Council.
- In principle, the trees 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 data. The total replacement comes as a last case, to not lose the history of the previous address in the OSM.
QA
After uploading to OSM, we can check some issues such as if a tree is exactly on top of a road. Given the high quality accuracy (positioning), this data can be used to fix road positioning (along with other data, such as official high-res orthophotos and road alignment (both from the same survey, and available on JOSM or iD)).
Final remarks
The import was done successfully. As planned, we only uploaded the trees were no conflict was found. Later, we conflated manually the existing trees, fixing their positioning using official data (the tree data itself and official high-res orthophotos), without deleting them. More than 94,000 trees were added/updated.
Acknowledgments
We would like to thank Prefeitura Municipal de Dourados (Dourados City Council), especially Mr. Ênio Alencar da Silva (Director of Geoprocessing Department - SEPLAN) for not only allowing us to use their data, but also being available to support us on this import.