Showing posts with label Asset Map. Show all posts
Showing posts with label Asset Map. Show all posts
Public Park Accessibility in the City of Vancouver
I am very happy that Vision Vancouver Councillor Reimer tabled a notice of motion yesterday called "Protecting Vancouver’s Public Green Space" which included the following statement:"The Greenest City Action Plan adopted by Council in 2011 sets a target that every person in Vancouver lives within a five-minute walk (400 metres) of a park, greenway or other public green space by 2020"
My first thought when reading this was simple: how will this indicator be measured? Specifically, I recalled a recent diagram in the Oakridge rezoning application slides (a project I fully support, just for the record) that shows 400 metre buffers from surrounding parks:
The trouble with this diagram is the 400 metre buffers appear to originate from the park centroids. Alternatively, I beleive 'accessibility' has actually been measured based on a buffer from the outer edge of parks. In other words, if I leave my house and walk 400 metres and arrive at the edge of a park, I would consider it to be accessible. I decided to explore these two interpretations; the following map shows the area within a 400 metre buffer of park 'centroids' in medium green, and the area within a 400m buffer from park 'areas' in lighter green:
In addition, I also clipped each 2011 Census Dissemination Block to the 400 metre buffer from the edge of parks, and calculated the fraction of each block that was within the threshhold. The fraction of the area was then used to calculate a proportion of the population per block that has no park accessibility. For example if a block had 100 people and it was 75% within the buffer zone, 25 people were considered to have no access to a park. As a result of this analysis, I determined that 79,407 people or 13.2% of the population of the City of Vancouver live greater than 400 metres from the edge of a public park. These people are shown using the yellow proportional symbols in the map below:
I also reviewed the Greenest City progress report and noted the indicator the City has selected is significantly simpler.Their indicator is "Percent of city's land base within a five-minute walk to a green space". In other words their target is based on area instead of population. Which is fully valid, but I still wonder how if they are measuring their covered area based on buffers from the park centroids (as shown on the Oarkridge map) or from outer edge of the parks (which would yield a larger total covered area and I am fairly confident this has been done). At the end of the day, I do not mean to criticize the outstanding work the City is doing, I am simply trying to highlight how an oversimplified diagram can lead to ambiguous results.
I am excited to learn more about this motion as it is developed because I have been working on many projects related to this theme at Golder Associates Sustainable Communities Group over the past few months. For example, I have conducted extensive GIS analysis and visualization to support the City of Vancouver's ongoing Integrated Stormwater Management Plan (ISMP)and the John Hendry (Trout Lake) Park Master Plan.
I understand this Notice of Motion is referencing much more area than just parks, and exactly what should be considered 'greenspace' will likely be a topic for a future post. For example, community gardens and greenways are referenced in the Greenest City action plan as features that satisfy the 'greenspace accessibility' target. Alternatively, given my recent focus on stormwater management I would also suggest it may be equally important for the City to implement a 'no net loss of pervious surfaces' target to maximize onsite infiltration of rainwater.
I hope this post shows that GIS tools are not always as objective as they appear and it is important for policy makers to consider how various calculation methods can impact progress towards targets.
Garden Deserts: Community Garden Plots per Person in Vancouver
Do you want to sign up for a community garden plot in Vancouver? If so, you are not alone - demand for garden space has surged in recent years as the local food movement has become mainstream. According to data published on the City's Open Data Site, there are approximately 3,965 garden plots of various types in the City and there are about 600,000 people in Vancouver. Therefore, there is approximately 1 garden plot per 150 people living in the city today.
After I created an interactive map showing all Community Gardens and Food Trees last year, I was asked by the Evergreen BC 'Seeding Healthy Communities' program coordinator if I could explore the distribution of garden plots within the city, with an eye towards understanding the spatial accessibility of existing gardens to citizens. I volunteered to conduct this analysis because I wanted to know if there were 'garden deserts' within the City where population-based demand for plots was much greater than supply?
I began by visualizing the number of plots per garden location as shown on the map below:
I also mapped the total population per census block based on the Statistics Canada's 2011 Census of Population.
To evaluate the relative supply and demand for garden plots within Vancouver, I transformed the point data from the two maps above into kernel density surfaces, based on the number of garden plots and people within 1 km from every point in the City. This process yeilded two surfaces, the number of plots per square kilometer and the number of people per square kilometer - I then divided these to derive a measure of 'Garden Plots per 1,000 People' as shown in on the map below. The dark green areas are relatively well served while lighter yellow and grey areas have very few or no plots per person:
I am a big fan of the City of Vancouver's Greenest City initiative that among other goals has supported creation of many new community gardens in the past few years, but I believe more gardens are still needed. What is the right number? That I cannot say. But I would suggest this map could be used to help plan where additional gardens may be needed from a spatial equity perspective. Although policy makers and advocates should also weigh other variables such as income level of communities. Additionally, there may be relatively less need for gardens in currently 'underserved' areas of the city where single family homes may have back yard gardens that may seem to negate the demand for community gardens.
That said, as a proud member of the Cypress Community Garden in Kitsilano, community gardens have a much greater impact beyond increasing local food security. In my experience gardens have an important role in increasing community social connectedness, which has in turn been linked in a recent Vancouver Coastal Health survey to improved sense of health and well-being. So with each new garden that is planted, we may in fact be growing a healthier community for generations to come.
CLICK HERE TO SEE MY THE INTERACTIVE MAP OF ALL COMMUNITY GARDENS
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After I created an interactive map showing all Community Gardens and Food Trees last year, I was asked by the Evergreen BC 'Seeding Healthy Communities' program coordinator if I could explore the distribution of garden plots within the city, with an eye towards understanding the spatial accessibility of existing gardens to citizens. I volunteered to conduct this analysis because I wanted to know if there were 'garden deserts' within the City where population-based demand for plots was much greater than supply?
I began by visualizing the number of plots per garden location as shown on the map below:
I also mapped the total population per census block based on the Statistics Canada's 2011 Census of Population.
To evaluate the relative supply and demand for garden plots within Vancouver, I transformed the point data from the two maps above into kernel density surfaces, based on the number of garden plots and people within 1 km from every point in the City. This process yeilded two surfaces, the number of plots per square kilometer and the number of people per square kilometer - I then divided these to derive a measure of 'Garden Plots per 1,000 People' as shown in on the map below. The dark green areas are relatively well served while lighter yellow and grey areas have very few or no plots per person:
I am a big fan of the City of Vancouver's Greenest City initiative that among other goals has supported creation of many new community gardens in the past few years, but I believe more gardens are still needed. What is the right number? That I cannot say. But I would suggest this map could be used to help plan where additional gardens may be needed from a spatial equity perspective. Although policy makers and advocates should also weigh other variables such as income level of communities. Additionally, there may be relatively less need for gardens in currently 'underserved' areas of the city where single family homes may have back yard gardens that may seem to negate the demand for community gardens.
That said, as a proud member of the Cypress Community Garden in Kitsilano, community gardens have a much greater impact beyond increasing local food security. In my experience gardens have an important role in increasing community social connectedness, which has in turn been linked in a recent Vancouver Coastal Health survey to improved sense of health and well-being. So with each new garden that is planted, we may in fact be growing a healthier community for generations to come.
CLICK HERE TO SEE MY THE INTERACTIVE MAP OF ALL COMMUNITY GARDENS
Vancouver Community Gardens & Food Trees
This interactive map shows the locations and attributes of community gardens and food trees in the City of Vancouver. While these community food assets are located within city boundaries, and some on City of Vancouver and Park Board lands, the vast majority of these locations are not administered by the CoV. This dataset was downloaded from the City of Vancouver's Open Data Portal on July 15, 2012. Please remember that lots of love and hard work goes into growing food so please do not remove food from a community garden plot without permission from the owner! I am a member of Cypress Community Garden and we were very sad to loose some rhubarb last month. If you would like to learn more about locally grown food, just ask...in my experience most gardeners are happy to talk about their crop and might even be willing to offer you a taste!
CLICK HERE FOR FULLSCREEN MAP
Mount Pleasant Family Asset Map
You may also view Mount Pleasant Family Asset Map in a full screen view
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