Background-
Over the last few weeks, we have gathered temporal, humidity and land cover data in the Collins View neighborhood to view the way in which an ecosystem’s patterns are disrupted by increased urbanization and development, specifically in a suburban neighborhood in which little remains recognizable after eighty years (see Labs One and Two for further insight on the gathering of such data). In collecting this data, we were able to then compare it to the data of eleven other sites in the neighborhood and surrounding areas that were more or less manipulated, in order to note temporal (and other) changes based on this variation in urbanization (see Lab Three for more details on this). Now comes the time in which we can compile that data and analyze possible correlations. In an area as diverse as Portland, land use has remained inconsistent, yet ever expanding, in the last eighty years. But how much has this urbanization and development presented shifting externalities in the ecosystem?
Procedure-
In order to compare all data more qualitatively, I created a visual of the quantitive data previously gathered. In Lab Three, we compiled the data of twelve land cover sites (my own and eleven colleagues) into a single spreadsheet/table in Numbers (an Apple Excel application). After removing any qualitative data, I imported this table into and ARC GIS mapping system to convert the data into a layer on my base map. I also imported three more layers of mapping that displayed spatial data, specifically the boundaries of the three types of locations data was gathered from (Lewis and Clark’s campus, the Collins View neighborhood, and Riverview Natural Area). Between these four mapping layers, I was able to distinguish possible changes in the ecosystem correlating to these different forms of new landscaping.
After analyzing the data from this (results below), I compared satellite images from four different time frames (1939, 1961, 1982, and 2018), exhibiting the urbanization and burst in development during different periods of the mid-late 1900’s.
Results
In comparing the data through visualization by mapping, I was able to notice some patterns that lead to theories of environmental disturbances resulting from increased urbanization. In the two maps below, the three areas of Southwest Portland being researched are laid out, in addition to the twelve sites within them (four sites in each). The circles at each site are measuring data gathered (see keys to left of each map for further details), presenting an obvious correlation in temperature and canopy/ground cover. Notice the adverse effect on temperature range, which increases as ground/canopy cover decreases. This is most obviously present in comparing RVNA overall, to Collins View as a whole. In RVNA, a consistently high percentage of ground and canopy cover emerges. With this, however, also comes the lowest temperature ranges (on average) and thus, temporal consistency, of the three site boundaries. Meanwhile, the Collins View neighborhood seems to present a higher variation, but lower overall percentage, in the amount of ground and canopy cover, as urbanization has occurred here more heavily (while RVNA has gone relatively undisturbed). In addition, the Collins View neighborhood seems to experience the highest range of temporal readings.
Left: 1939 Photo
Below: 1961 Photo
Below: 1982 Photo
Below: 2018 Photo
In comparing satellite photos of the area from 1939, 1961, 1982, and 2018, the urbanization and increased growth in the area is obvious. Each decade contains increased concrete/buildings and decreased foliage. Areas in RVNA have been less disturbed (practically undisturbed in terms of clearing/building), further backing my claim that these undisturbed ecosystems contain less fluctuating variables with more consistent readings. While Collins View is not visible in all these photos below, in is in the 1939 photo, as well as recent, and Lewis and Clark’s campus is highly visible. Both these locations show a dense amount of shifting and manipulation from ’39 to now, but it seems that urbanization really began to unfold sometime between the 60’s and 80’s where foliage cleared for an influx of urban populations moving in, not to mention a larger college campus. These shifts in the ecosystem, combined with current temporal, land cover, and cover change data, help with my understanding of how is has affected local climates.
Discussion-
These results may only be of Southwest Portland itself, but these results are telling in possible larger-scale implications. If urbanization has noticeably impacted this local ecosystem, imagine how it has effected the ecosystems of other areas, such as downtown or next to natural resources (such as bodies of water) , where higher, denser populations have led to more intense volumes of urbanization and growth than the busiest areas of the Collins View/RVNA/Lewis and Clark neighborhood. As we continue to shift the planet’s overall canopy and ground cover percentages downward, what will happen to the increasing temperature range that results from such? I would love to begin to start researching these larger changes, and how this, in turn, is effecting the planet’s overall climate change (considering that is bringing just this, larger temporal/climate variations).