Daniel Kogan
Geovis Project Assignment @RyersonGeo, SA8905, Fall 2021
Introduction/ background
Every city has zoning bylaws that dictate land use. Most cities, including the City of Toronto, have zoning bylaws that set building height limits for different zoning areas. Sometimes, buildings are built above the height limit, either due to development agreements or grandfathering of buildings (when a new zoning by-law doesn’t apply to existing buildings). The aim of this project is to provide a visualization tool for assessing which buildings in Toronto are within the zoning height limits and which are not.
Data and Processing
3D Buildings
The 3D building data was retrieved from Toronto Open Data and derived using the following methods:
- LiDAR (2015)
- Site Plans – building permit site plan drawings
- Oblique Aerials – oblique aerial photos and “street view” photos accessible in Pictometry, Google Earth, and Google Maps.
- 3DMode – digital 3D model provided by the developer
Zoning Bylaws
Two zoning Bylaw shapefiles were used (retrieved from Toronto Open Data as well):
- Building Heights Limits – spatially joined (buildings within zoning area) to the 3D buildings to create the symbology shown on the map. Categories were calculated using the max average building height (3D data) and zoning height limit (zoning bylaws).
- Zoning Categories – used to gain additional information and investigate how or why buildings went over the zoning height limit.
Geovisualization
ArcGIS experience builder was used to visualize the data. A local scene with the relevant data was uploaded as a web scene and chosen as the data source for the interactive map in the “Experience”. The map includes the following aspects: Legend showing the zoning and height categories, a layer list allowing users to toggle the zoning category layer on to for further exploration of the data, and a “Filter by Height Category” tool that allows users to view buildings within a selected height category. Pop-ups are enabled for individual buildings and zones for additional information. Some zones include bylaw expectations which may explain why some of the buildings within them are allowed to be above the zoning height limit (only an exception code is provided, a google search is required to gain a better understanding). instructions and details about the map are provided to the user as well.
Limitations
The main limitation of this project is insufficient data – a lack of either building height or zoning height results in a category of “No data” which are displayed as grey buildings. Another limitation is possibly the accuracy of the data, as LiDAR data can sometimes be off and provide wrong estimates of building height. Inaccuracies within 1m were solved by adding an additional category, but there may be some inaccuracies beyond