Bend building import

About

The city of Bend, Oregon has offered a complete building footprints layer with an OSM-acceptable license. The current building footprint layer in OSM contains about 1,100 buildings (as of 9/26/16), mostly traced by hand from satellite imagery. The building footprints file available from the city contains more than 36,000 features. In addition, building heights and addresses can be derived for each building from publicly-available data sets.

Import Plan Outline

[x] Acquire data from city

[x] Determine OSM tags to be included

[x] Process data

[ ] Divide data into discrete tasks

[ ] Complete import

Goals

Add an extensive building footprints layer for Bend, Oregon, to OpenStreetMap with tags for addresses and building heights.

Schedule

Planning meeting with interested volunteers scheduled for Oct. 6, 2016.

Generation of height and address fields was completed in April 2017.

Import Data

Background

Building footprints shapefile: https://github.com/MaptimeBend/bend_buildings/tree/master/data

Data license: https://raw.githubusercontent.com/MaptimeBend/bend_buildings/master/data/building_footprints2004_intlfeet_disclaimer.txt

Additional data

Deschutes County open data taxlot file: http://data.deschutes.org/datasets/28019431cced49849cb4b1793b075bf1_2

Deschutes County open data assessor info (for addresses): http://data.deschutes.org/datasets/aea94004ae8c49e6a6dec394522677ad_1

Oregon DOGAMI lidar data: https://coast.noaa.gov/htdata/lidar1_z/geoid12a/data/1452/

OSM Data Files

Not yet created.

Import type

One-time import.

Data Preparation

Data Reduction and Simplification

Probably not necessary. Most buildings are basic rectangles with few points that could be removed.

The buildings shapefile contains several fields that will be eliminated as they are artifacts of the file's CAD origins.

Tagging Plans

We'll include new tags for height, addr:housenumber , addr:street and addr:postcode. In addition, we'll retain existing tags for nodes and areas that will be updated with our import. We'll use the Replace Geometry tool in JOSM as needed to retain existing tags and history.

Changeset Tags

Bend, Oregon, Building Import #bendbuildings https://wiki.openstreetmap.org/wiki/Bend_building_import

Data Transformation

For detailed and reproducible transformation instructions, see our Github ReadMe.

All data were transformed to meter-based NAD83 / Oregon South for processing, then transformed to WGS84 for import.

1. Building shapefile imported to new Postgis table.
2. Taxlots and address tables imported to new Postgis tables.
3. Addresses joined 1:1 to taxlots via taxlot ID.
4. Each building polygon assigned housenumber, street and postcode by spatially joining the centroid of each building to the taxlot polygons.
5. Using raw lidar data, a 25 centimeter Height Above Ground Level raster for the entire city was created.
6. Using zonal statistics, a height field was derived for each building footprint.
7. Dataset exported to GeoJSON in WGS84
8. OSM data file generated via JOSM.

Data Transformation Results

Example of transformation results: Github Demo Page.

Data Merge Workflow

To be discussed at Oct. 6 meeting.