Issues of equitable land use in Portland have been magnified by gentrification and population increase. Our results have identified several key barriers to accessible green spaces in Portland. Urban sprawl is an issue and the city’s urban growth boundary is constantly getting expanded. Our GIS map illustrated the high levels of urban sprawl around the periphery of Portland. Within the neighborhoods on the periphery of Portland there was low proximity to green spaces and high index scores for urban sprawl. Within the core of the city the relationship was more complicated. Neighborhoods in the west had high proximity to green spaces as well as urban sprawl that was higher than average, though still not as high as on the outskirts. Neighborhoods in the northeast were the most compact but also had the greatest variation in access to urban green spaces. This may be due to different types of land use, even within the compact center of Portland. This area contains industrial, residential and commercial neighborhoods, all of which have different effects on available green spaces.
Our statistical analysis also shows that the neighborhoods that have experienced the most growth from 1980 to 2010 are in closer proximity to green spaces. This makes sense; people enjoy living close to green spaces, thus new properties are built near green spaces. There is also a strong correlation between neighborhoods that have high populations and neighborhoods that are close to green spaces. This is especially strong with the 1980 population, but is still very strong in 2010. The fact that this correlation has gotten weaker while there is still more growth happening closer to green spaces could show that people are being forced to move farther away from green spaces as new, richer people move in.
Urban green spaces have been shown to be unequally distributed, and Portland is no exception. Maps were made comparing access to green spaces to the spatial distribution of different racial demographic groups in Portland. The most salient trend was that between green spaces and African-American communities. African-American communities were highly concentrated in a select area towards the north of Portland’s core, an area with a low range of proximity to green spaces. Portland has been criticized for gentrification and not including all groups equally in urban planning, which this further proves. Adding green spaces to urban areas has been shown to increase residential property values, which may expedite gentrification. The areas in Portland’s center already have housing shortages and inflated property values, which begs the question of whether adding green spaces further contributes to these problems. It is therefore important to note that neighborhoods in west Portland have the greatest access to green spaces but also have scarce African-American communities. This inequitable distribution of green space warrants attention from the city of Portland and may hint towards unequal access to other natural resources.
After this, we looked at the relationship between green space proximity and the urban sprawl index in Portland neighborhoods. We found a very strong correlation, especially with peripheral neighborhoods, like those way in southeast Portland, that had the lowest urban sprawl index (the most urban sprawl) and the least amount of access to green spaces. This shows that there is in fact, a strong relationship between urban sprawl and green spaces in Portland, and it is not, as the Urban Greenspace Institute claims, “that well-designed, nature-rich cities are beautiful, equitable, compact, and ecologically sustainable places to live, thereby reducing urban sprawl across the rural landscape” (Integrating 2015). Green spaces do not reduce urban sprawl, and may even help contribute to urban sprawl as people with money move near green spaces, pushing established communities farther to the city periphery.
On a larger scale, this emphasizes the need for equitable distribution of urban green spaces. Ideally, everyone would have easy-to-access green spaces. This would ensure that their health, ecological, and aesthetic benefits could be available to every neighborhood. And while complete equal distribution is not possible, by implementing and emphasizing urban green spaces in more marginalized neighborhoods, the effects of urban sprawl and gentrification could be combatted. However, this is difficult for cities such as Portland that already have these marginalized neighborhoods with no real place to put in a park or forest area. Something that can be done would be to embrace other urban green spaces such as urban gardens or trees in these areas, as several organizations are doing in Portland, or to purposefully implement green spaces in favorable places in new neighborhoods.
For cities that are still rapidly growing in physical size, it will be important to take careful planning into where to implement green spaces so that there is equal accessibility to prevent help prevent gentrification. Cities will have to think about both the positive and negative effects of urban green spaces to carefully plan the placement of green spaces and ask whether or not it reinforces or prevents disparate neighborhoods. Yet, it is difficult to say definitively the best solution, because it depends greatly on the characteristics of each individual neighborhood for every city. An equitable distribution of land use will have to be aware of the effects green spaces will have on city neighborhoods.
Unfortunately, our project was limited by time, resources, and available data. We would have liked to look at other variables, such as the housing market for each neighborhood or the amount of urban trees, but we only had access to limited amounts of data. Also if we had more time, it would be interesting to see how Portland’s population changed at various time intervals, instead of just 1980 and 2010. Further research could also be done on what types of green spaces contribute the most to urban sprawl. For example, I would imagine that large, forested, water-front parks would contribute much more than just street trees or a small garden. In addition, a stronger case for this trend could be made if situated research was done in many other cities around the world. It would also be interesting to see if there are global trends that show if cities that experience the most urban sprawl or gentrification have more or less total green space area.