Canada:Ontario:Ottawa/Import/Trees

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Tree Inventory[1] is a dataset containing approximately 149,000 trees owned by the City of Ottawa

Overview

This dataset is available on the City of Ottawa's open data portal, as part of a government initiative for open data.[2]

The availability of this data on OSM could benefit users in searching for or creating a map of trees within the city. For example, fruit-bearing trees that can be harvested for consumption.

Licence

Open Data Licence Version 2.0[3] (Approved by the Licence Working Group)

Data Collection

From the dataset source page "This data was collected in the field using GPS software on handheld computers"

Data

The data being used is a .osm file that has been modified from provided source data. The one that is being used is the KMZ format as is was already in WGS84 projection.[4]

Tags

The KMZ format had tags that are not usable in an OSM format and thus had to be cleaned and modified with proper OSM tags.

Entries without OSM tags were removed from the source data.

Entries with only OSM tags were manually added based on research (meaning a quick Wikipedia search)

Original Key OSM Tag Example Description
leaf_cycle deciduous
leaf_type broadleaved
natural tree
source City of Ottawa
survey:date 2013
genus Fraxinus
genus:en Ash
species Fraxinus pennsylvanica
SPECIES species:en Ash Green What species is the tree
name ref 119561
DBH dbh 9 The diameter of the tree (Diameter at breast height)
ADDNUM 40 Civic number associated with the trees location
ADDSTR ROYAL FIELD CRES Street name associated with the trees location
RDLOCATION Boulevard Is the tree located in a Median, Boulevard etc
LTLOCATION Rear Is the tree located on the side/front of the parcel
DEDTAGNUMB 0 Tag number associated with Elm trees involved in the DED injection program
EABTAGNUMB 0 Tag number associated with Ash trees involved in the EAB injection program
OBJECTID 145303
WARD 3 What ward is the tree located in

Import Process

The process will be dealt with using the osm-ca Tasking Manager to ease the work flow as there is a lot of data to be added.

The time frame can expect to be only a couple days at most after getting approval from the community.

Issues

Use of new tag

The biggest issue I can see with this data is the use of the DBH tag. The suggested OSM tag to use is circumference, however DBH is a much more common measurement in botany.

Current Trees in OSM

There are about 6,021 trees in OSM within the area of the dataset. Of those, only 3 have anything more that natural=tree and neither of them overlap with what is being imported. If any of the remaining 6,018 trees are overlapping with the data set, simply using the m key to merge the existing node to the new one will fix this and retain history of said node.

References

  1. Tree Inventory dataset
  2. City of Ottawa Open Data Portal
  3. Open Data Licence 2.0
  4. Original source dataset