Each week I will be blogging about a different (and interesting) application of GIS that everyone can relate to. This week's post is going to talk about geospatial analysis, specifically related to how new construction (ie development) has occurred in the City of Victoria in the last two decades. What I wanted to do this week was look at (1) how development has generally played out in the City since 1996 and (2) whether or not we could use GIS to discover if there are any catalyzing effects of new development.
Catalyst developments? Cities occasionally use catalyst developments a strategy to spur urban revitalization. Catalyst projects can make areas more attractive for citizens and visitors, spur investment and development and add diversity and energy to previously less vibrant areas. The question is: do catalyst developments actually work and can we possibly identify them through GIS?
What does this have to do with GIS? Well thanks to the current push for open data and specifically building permit applications (thanks City of Victoria!), we can use GIS to visualize developments by value as they occur over time and space. We can then use GIS to look at what level of development has occurred downstream in time and space from any possible catalyst location to see if it had any effect on its surrounding neighborhood.
The set up: For a change, I thought I would use the City of Victoria as an example for this type of analysis. The City has helpfully made available all of their development permit data from 1994-2017 (including values, purpose and locations). Its a treasure trove of data! Being the huge data nerd that I am, the first thing I did was map everything (this may take a minute or two to load..):
What are we looking at? this is every building permit in the City sized by value and displayed by year from 1994-2017. It's a bit overwhelming, so I filtered down the data quite a bit:
First thing was to remove all building permits that were not new construction;
Second, I removed any new construction permit that was less than $2,000,000 (not in real dollar terms, that's for a future piece of work);
From that, I then mapped the spatial temporal relationships between all of these filtered records of construction;
Using these relationships, I assessed where each development fell in time and looked at all developments that occurred after that building permit and were within a 600m radius;
I then totaled the values and picked the top 20 developments with initial construction values over $10m and downstream development values of over $40m
If that didn't make any sense, then let's try an example:
In 1999, the Hotel Grand Pacific added new guest rooms and renovated the whole building. At the time, it was a $20m job. 15 years later 21 new developments occurred within a 600m radius of the hotel for a total of $201m in construction permit values.
Did the hotel redevelopment catalyze development in the area? Well certainly there has been a lot of development in the Downtown Core and in James Bay, so it may be a likely candidate. Luckily we have the rest of the data to use a visual cue, so let's take a look. The following animation shows the interconnected nature of development in Victoria. You'll note a lot activity in Vic West, along Humboldt Street and in the Downtown core. (the animation may take a few seconds to load so be patient!). The size of blue circles is the development permit value, and the size of the purple circles is the total accumulated value for each potential catalyst location. The connecting lines are colored by each catalyst development to give you an idea of area of influence. The table below summarizes the animation.
The Wave or The Marriot? Well, based on either 12 or 14 years of downstream data, both of these developments may be able to claim "Catalyst" in their title. You can probably note that the Save-on-Foods Memorial Center and Mount St. Mary Hospital are not far behind... Now, this of course is a basic introduction into a much more complicated question that begs a few caveats...
Building permit values are not construction values or actual building values, indeed, they may be off by orders of magnitude. However, We can potentially use BC assessment data to fill this gap;
600m in space is arbitrary. If we looked at 200m or 1km would we see a much different answer in terms of spatial effects;
Correlation is not causation. Just because something happened before something else in time, doesn't mean that it caused it. There are a lot of factors that affect land development and this analysis just scratches the surface on most of them; and
The data could be wrong to begin with. While I am sure that the City took every care to scrub their data in advance of publication, it is highly likely that there are errors in the information. Assuring the data before using it will very much likely add to any analysis like this in the future.
Standard pitch: If this was even remotely interesting to you, or if you feel strongly on what I have done here, then do not hesitate to contact me as soon as convenient. I would love your feedback.
Coming up next week: Defining markets through spatial analysis to identify the best location for a new full-service grocery store