Tenerife streams import

Import propossal for http://tareas.openstreetmap.es/project/43

Goal

In the map of Tenerife there are 4859 ways with the key waterway=stream, but most of then are without name. The Hydrologycal Plan of Tenerife contains a list with the names of the natural waterways in the island. This project aims to:

1. Name the unnamed streams in OSM.
2. Checking existing names.
3. Drawing the missing channels in OSM whenever it is possible to trace them through aerial image.
4. Checking the wikipedia=* tag for the streams that appear on wikipedia:es:Categoría:Barrancos_de_Tenerife.

Schedule

This is a long-term work without strict planning. Important milestones will be noted here.

• 03-02, 2017. Discussion in the Talk-es list (in spanish).
• 03-20, 2017. Discussion in the imports list.
• 03-29, 2017. Message to Telegram room. Work begins. Publication in task manager.
• 03-31, 2017. Vectorized the map as a help to search the streams.
• 05-06, 2017. Work done. Validation remains pending.

Import Data

Background

• Data source site: http://www.planhidrologicodetenerife.org
  
• Data license: Public Domain
  
• Link to permission: artículo 13 de la Ley de Propiedad Intelectual española
  
• Attribution: source=Plan Hidrológico de Tenerife in the changeset tags.

Permission

Spanish legal provisions and their corresponding projects are not subjected to copyrights according to Article 13 of the Spain Intellectual Property Law.

Data description

PDF document (16.9 Mb) with:

• List of main streams in Tenerife.
• List detailling the tributary streams for each main stream.
• Location map split in 49 sheets showing the watercourses.

The streams lists contains this data (only fields in bold will be used):

• Id. Cauce: Unique identifier of the stream. It could be used to locate the stream in the location map.
• Cat.: A character indicating if the stream have been checked as public in all the watercourse (C) o in some parts of it (c).
• Nivel: A number in the 1..10 range that show the level of this stream into the tree of tributaries.
• Orden: A key showing the sequence of this tributary watercourse into its mains streams .
• Topónimo: Main name of the stream.
• Alónimos: Alternative names of the stream.

The dataset don't have geographic coordinates. The name of the streams will be translated to OSM in a manual process using the location map.

Import Type

This is a one time, full manual import.

Data Preparation

Data Reduction & Simplification

The dataset have the names of 5497 waterways, of wich 488 are main streams (ends in the sea) and the rest are their tributaries. There isn't any preliminary reduction of the dataset, during the work the streams that do not exist in OSM and can not be traced over aerial image will be discarded.

Tagging Plans

Original field	OSM tag
Topónimo	name=*
Alónimos	alt_name=*

Each watercourse should have this tags:

• waterway=stream
• intermittent=yes

Changeset Tags

• source=Plan Hidrológico de Tenerife; other data sources
• type=import
• url=http://wiki.openstreetmap.org/wiki/Tenerife_streams_import

Data Transformation

A bash script extracts from the PDF document the dataset and maps that will be used to search for the streams and copy the tags. No data is generated to import directly. The script is in this repository.

Data Transformation Results

The result files are in the repository:

• cauces.csv: Table with reference and names of all the streams.
• cauces??.tif: Location maps. You can open it in JOSM with the JOSM/Plugins/ImportImagePlugin.
• cauces??.kml: Vectorized location maps.

Data Merge Workflow

Team Approach

Import will be undertaken by experienced OSM volunteers, following a strict workflow.

Workflow

Tools

• The JOSM editor.
• The spanish tasking manager server.

Preliminary steps

1. Create an account like usuario_imports with an email not already registered in OSM. If you use gmail, you can use your usal address adding "+imports" before the 'at'. Example: peter+imports@gmail.com
2. Put this account in JOSM settings.
3. Enable the remote control in JOSM: Settings (F12) > Remote control > Enable remote control.
4. Install JOSM/Plugins/ImportImagePlugin.
5. Download the files from here or run the script to generate the location maps and dataset.
6. Give authorization to use your openstreetmap account in the tasking manager in the link 'login to OpenStreetMap'.
7. Select an area and clic in "Start contributing".
8. Open this area in JOSM with the link 'Edit with Josm'.

Main steps

1. Select the existing streams, Edit > Search: "waterway=stream" and add them to the ToDo list.
2. Open as a background image the geotiff of the location map corresponding to this area, which number is showed in the area detais in the tasking manager.
3. If you view streams in the location map that don't exists in OSM, or are incomplete, draw them whenewer you can detect the watercourse in the aerial background and add the new ways to the ToDo list. The availlable data sources for Tenerife are: Ortofotos de Grafcan and PNOA. It's good to use background images with diferent adquisition date in order to get the best light conditions.
4. Examine each way in the ToDo list,
   1. Locate the reference of the stream for this way in the location map.
   2. Search using the reference the stream in the list cauces.csv.
   3. Add the tags indicated in #Tagging Plans.
5. Repeat until the ToDo list is empty.

Conflation

1. If we find a conflict between the existing name in OSM and the name of the PHT.
2. If it is an orthographic difference, use the PHT.
3. If the name tag in OSM is one of the names collected as alternative names in the PHT, use those in the PHT.
4. It may also be a correct name for this section of the stream. Each channel has a single main name in the inventory, but may have particular names for different sections of the watercourse. In that case, preserve the OSM names and assign the PHT names to a Relation:waterway for the entire stream.
5. If we find significant variations between the tracing of a stream in the PHT location map and the tracing following the aerial image, the name of the PHT is not collected.

Last notes

1. Make sure to use the user created in Josm for the import.
2. Upload the edits to OSM assigning the #Changeset Tags.
3. Mark the task as done in the tasking manager.

Regresion plan

In case of any trouble, [JOSM/Plugins/reverter] will be used.

Updates

These are static data, no updates are expected.

Quality Assurance

Each area edit can be validated in the tasking manager.