Engineering Rome

Analysis of Urban Greenery in Rome

By: Sam Scherer

1. Introduction

Walking around Rome one immediately notices the impressive structures, the cobblestone roads, and the overall beauty of the city. Something that contributed significantly to the allure of the city was its parks. Many of the parks used to be these sprawling estates adorned with gorgeous gardens and fountains. These parks serve as so much more than just a tourist attraction though; parks are incredibly important for a healthy population, reducing stress in individuals and lowering blood pressure as well as providing an area for physical activity. In addition to the anthropogenic benefits, they also have environmental benefits by increasing water retention in cities, combating the urban heat island effect, and decreasing both air and noise pollution. Exploring all of these topics and using a study that researched characteristics of parks and preference as a metric for comparison, this report will serve as an examination into the perceived benefits of parks and how the parks of Rome parallel the literature.

2. Background

When looking into the benefits that parks provide for human health, it has been theorized that parks are able to decrease stress and improve cardiovascular health by providing a space for exercise. In addition to, or as a result of these factors, parks have also been perceived to have a positive effect on the mental health of individuals who frequent them.

In regard to the perceived positive effects of parks on the environment, they have been linked to decreased temperatures in urban environments as they are able to absorb the heat and not reflect it back into the atmosphere. Parks also have the added environmental benefit of increasing water retention, which is important for cities such as Rome that have historically had issues with flooding. Considering that they also do not have roads running through them and are usually large enough that they are far from roads, parks have also shown decreased levels of air pollutants such as particulate matter.

3. Parks and Perceived Anthropogenic Health Benefits

3.1 Stress and Cardiovascular Health

Stress, a feeling we humans are well-acquainted with, releases hormones such as cortisol or adrenaline. In this time, there is a release of sugar into the bloodstream that is combined with an increase in blood-pressure and heart rate to circulate the energy from the sugar quickly (Gourdarzi, 2007). As humans experience stress on a daily basis because of a variety of stimuli, this chronic stress can increase the risk of high blood pressure and adult-onset diabetes from the frequent release of sugar into the bloodstream (Gourdarzi, 2007). Green spaces such as parks however have been found to decrease stress levels and blood pressure (Hedblom, 2019). Additionally, there has been an observed reduction in noise pollution in green spaces which positively affects stress levels as noise is a stress-inducing stimulus.  

Having green spaces in urban areas is incredibly important and is linked to a variety of benefits. One of which is positive changes to cardiovascular health; in a study done to determine the effect of green spaces on heart rate, the researchers took the participants into three different green areas in Helsinki, Finland. The areas were an urban forest, an urban park, and the city center (Lanki et. al., 2017). During the visits, they had 15 minutes of sitting time and 30 minutes of walking around; the results of their study displayed a lower heart rate in the urban forests than in the city center. Even for short visits, it was shown to have a relaxing effect. Additionally, in urban green spaces the air pollution is lessened, which contributes to the experienced lower blood pressure as particulate matter has been shown to increase systolic blood pressure.

The addition of parks in urban areas also presents the opportunity for physical activity which decreases risk of high-blood pressure related ailments and improve cardiovascular health (Braubach et al., 2017). A variety of studies that were performed found that with increased access to green spaces came increased levels of exercise. By providing an accessible and conveniently located area to exercise, this can promote an increase in time spent outside and engaged in physical activity, which is especially beneficial for those that are have mental health issues (Braubach et al, 2017). One study done in Scotland looked at the difference between exercise done in natural versus non-natural environments, and found the association of exercise in natural environments and a further decrease in the risk of poor mental health, while exercise not in these environments did not show the same advantage (Braubach et al, 2017).

4. Parks and Environmental benefits

Not only do urban green spaces improve human health, but they also improve the health of the city. Within my first few days in Rome, there was a large thunderstorm that brought heavy rainfall leaving many pools of water around the city. Urban green spaces, such as parks, help to combat this issue as they are able to increase water retention by allowing the water to infiltrate the soil instead of sitting on top of an impermeable surface (International Network for Capacity Building in Integrated Water Resources Management, 2018). Shown in figure 1 below, the day following a large rain event there was a large pool of water that collected on top of the stones of the road. This type of surfaces in theory could be a good drainage system, allowing the water to go in-between the stones; however, on one of the tours in the program, it was said that many of the cracks between the stones have been rather haphazardly filled with asphalt in an attempt to fix them as they settle. Having the cracks be filled with asphalt therefore makes it difficult for the water to drain to the ground below. However, in parks this isn’t a problem as most of the space in them is open fields or vegetated, tree areas that allow for the rain to seep into the soil and eventually the groundwater table below.

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Figure 1: Large pool of standing water outside a piazza in Trastevere

The runoff from cities is concerning especially when considering the quality of that water and the impact on the receiving body of water. The streets of Rome are not the cleanest, as one may imagine, from the cars driving on them to the large number of people trafficking the streets as well. As the water sits on top of these surfaces, it can accumulate pollutants of all kinds that were previously on them. When the water is allowed to go into the ground beneath, some of the pollutants can be filtered out before reaching the receiving body of water, which in this case is the Tiber River. Parks, with their abundance of open ground, allows the water the pass through the layers of soil before entering the groundwater below and draining to the river. This is important considering figure 2 below illuminating the poor quality of the Tiber river. Water health is important for a city; apart from the obvious reasons, it is important for tourism, though maybe not for Rome as it has a number of other attractions to offset the quality of the river. Along the bank of the river there is a space where little booths and restaurants were set up; this could be a really neat attraction for the city, but not when it is next to a smelly, dirty body of water.

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Figure 2: Poor water quality of the Tiber River

4.1 Urban Heat Island Effect

The urban heat island effect describes the discrepancy in temperatures of urban areas and the surrounding rural areas. This difference in temperatures is a result of the number of paved roads and other surfaces that absorb and reflect solar radiation (EPA, 2019). It is been discovered that temperatures of urban infrastructure are about 27-50 degrees Celsius hotter than the temperature of the air. Because of this, cities remain hot even after sunset as the heat is radiating off of these surfaces (EPA, 2019). On average, the annual temperature in a city is around 1-3 degrees Celsius hotter than the surrounding rural areas, and in the evening, it can rise to nearly a 12-degree Celsius difference (EPA, 2019). Green spaces, such as parks, help to mitigate this issue as they have similar conditions to the surrounding rural areas and therefore do not experience this increase in temperature due to urban infrastructure. In figure 3 below, it can be seen that the temperatures are much higher in cities compared to parks. Given that the global climate has been steadily increasing over the last few years, this added benefit of parks being able to decrease both surface and air temperatures makes them an even more important aspect of cities.

Figure 3: graph showing average temperatures of different environments (EPA, 2019)

5. Factors Affecting Park Preference

In a study that was performed to test whether or not people reacted differently to built vs. natural environments, it was no surprise to find the participants in the study preferred the natural environments. The only built environment that could hold a light to the natural environments were human’s attempts to emulate them- urban parks (Kaplan, 1987). In his study, the urban parks were preferred as much as the lowest level of natural environments. Of the scenes that were preferred the most, they usually had either a trail that wound out of view or a well-lit opening that was in part hidden by intertwined vegetation. Additionally, in this study and subsequent studies, the relationship between the complexity of the scene and the preference to it was tested, but results showed that complexity was not a sufficient indicator for preference (Kaplan, 1987). By complexity, he was referring to the environment of the park whether it was densely vegetated or open field. In an attempt to discover what is an indicator for preference further studies were performed showing that, as he called it, coherence played an essential role. By coherence Kaplan is referring to the “capacity to predict within the scene.” (Kaplan, 1987). Or, the effortlessness that the observed scene is able to be broken down into digestible pieces. Using the variables tested- complexity, mysteriousness, and coherence, the outcomes of understanding and exploration emerged. Understanding (coherence) describes the comprehension of the scene whereas the exploration (mystery and complexity) details the ability of the setting to draw in the viewer.

Compiling the information obtained, Kaplan created the matrix shown in figure 4 below. On one dimension of the matrix, there are the outcomes understanding and exploration and on the other axis, this is describing the availability of the information in the scene, immediate or predicted. Legibility of the scene is describing the ability to “maintain orientation” as one continues further into the setting (Kaplan, 1987). The other terms have been introduced previously- complexity whether it is densely vegetated or wide open, coherence describes the ability of the viewer to easily understand the scene, and mystery is encompassing the park’s elements that draw the viewer in. This matrix is just an organizational tool that is supposed to describe the availability of the information that can be collected from the park, either immediate or inferred.

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Figure 4: Matrix Kaplan created to categorize and explain preference (Kaplan, 1987)

Summarizing the last bit of the report, the idea that human’s preference also depends on evolutionary factors was explored. In theory, people like to choose places that have an advantage, whether that is on top of hill where one can see the surrounding area, or have a place where one can observe but not be seen (Kaplan, 1987). It was discovered that the optimal place was not in a dense forest nor an open field where there is no cover, but on the tree line. To conclude his study, Kaplan says that the process by which one observes a space must be incredibly fast, which is somewhat contradictory to the fact that it is an incredibly complex and difficult process to describe the factors in which are considered when deciding preference (Kaplan, 1987).

Given the above information about environmental preference, what does this say about parks? Well, my interpretation is that there is a happy medium where parks are effective. One that is well maintained that provides tree coverage but is not so complex, as Kaplan would say, that it is overgrown with vegetation that it becomes frightening to navigate. Additionally, there is an aesthetic aspect in that well-maintained spaces are ranked higher than over-vegetated areas that are unkempt and borderline scary.

6. Analysis of Perceived Benefits and the Parallels to Roman Parks

6.1 Villa Doria Pamphili

Unlike other cities around the world, a large number of parks in Rome were not originally meant to be parks. In fact, many of the most famous parks around the city were private estates, villas, that were once owned by Italian noblemen, but have since been converted- a few examples of these would be the Villa Doria Pamphili or Villa Borghese. Given that Rome is a city that is thousands of years old, it is difficult to retroactively put in parks as a lot of the infrastructure has historical value and is densely packed. As parks contribute positively to the mental health of an urban population as well as the environmental health of the city, converting villas around the city to serve its population of nearly three million people was a creative solution to incorporating green space in the city (World Population Review, 2019).

To test the benefits of parks myself, I visited the Villa Doria Pamphili, Parco Acquedotti, and another one that served as a playground for children that was located in Trastevere. In figure 5 below, there is a map with the location of the above mentioned parks; in the figure, one represents the Parco Acquedotti, two represents the Villa Doria Pamphili, and three is the playground park. The Villa Doria Pamphili is park that used to be villa for an Italian nobleman back in the 17th century, and is today one of the largest parks in Rome (Villa Doria Pamphili). This park is roughly 184 hectares; if that is difficult to visualize, one hectare is roughly the size of a baseball field (Kleanthous, 2019). Being roughly the size of 184 baseball fields, this park is massive. In figure 6 below, while it is still a little difficult to really get a sense of how large this park is, included is the scale of picture on the bottom right. The numbers in the figure correspond to the location where the photograph in the following figures was taken; for example, figure 12 was taken near the villa seen below. Many elements of this former villa contained elements that would have put it near the top of the list of preferred scenes described by Kaplan. It has large trails that wound around the corner, employing an element of mystery; it also included large clearings that would be good vantage points to see all around, and tree lines to hide in.

Figure 5: Location of parks visited
Figure 6: Size of Villa Doria Pamphili and location of following figures within the park
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Figure 7: Tree-lined pathway
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Figure 8: Old chapel in the park

As seen from the pictures above, the park is indeed very pretty, and included the above-mentioned elements of winding pathways. Through the time spent here around sunset, there were a number of people there that were using the space. In the research, it was predicted that access to green space would increase physical activity, but that doesn’t always translate to what actually happens. Here, however, the assumption was validated. While walking through the park, there were a number of people either walking along the trails or engaging in another form of physical activity such as running or biking.

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Figure 9: Open field in the park

Because of the large size of this park and tree coverage, once you entered it through the archway in figure 10 below, it felt like you exited the city. For the most part I couldn’t see the surrounding buildings or hear the noise from the cars or surrounding vehicles. In the literature, it was stated that parks could reduce noise pollution (when large enough) which helped to reduce stress levels and therefore help to reduce blood-pressure and heart rate. While I did not have the instruments used in the studies cited above to actually measure my heart rate and blood pressure, I did feel and overall sense of relaxation while walking through the area. With the same disadvantage, I did not have a thermometer to measure the temperature inside the park and compare it to the surrounding temperature, but while I was in the park it did feel cooler than the surrounding city. Additionally, there were no pools of standing water.

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Figure 10: Arch at one of the entrances of the park, mysterious pathway leading out of view

One negative aspect of the park was that it wasn’t necessarily green and areas of it were a not very well-maintained. In figure 11 below, it can be observed that there were areas of the park that were over vegetated and unkempt, which detracted from the overall aesthetic quality. While some paths, like the one in figure 12 below, had lights that lined it, a large number of the paths were also lacking in lighting, making the space not as accessible closer to dark. In spaces that are not well lit like this at night it makes sense that attendance would decrease, especially when considering the large size of this area and how removed from people who could help an individual if they were in trouble. Studies performed in San Antonio, Texas found that statistically speaking, roads that were more lit than other were more likely to be found in areas that had lower crime rates- essentially areas that are more brightly lit experience less crime (Walter, Suk, 2019).

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Figure 11: Lack of green and manicured spaces
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Figure 12: Lamppost-lined pathway

6.2 Playground Park

While walking to a different tour, we walked past this little “park” that was a playground for children. I did not physically enter this space but walked past it. This park did not fulfill any of the items described by Kaplan. It had no pathways to be seen at all and no real corners for them to wind around to go out of view. There was no element of mystery as someone in the park would be able to see the whole thing since it is rather small. The park also lacked in a coherency-sense as it was rather difficult to process all that was going on in it given that it is so overgrown and ill-maintained. In fact, it is not maintained at all, there were weeds growing up all over the place as seen in figure 13 below, and it is right next to the road and surrounding buildings so the same feeling of escaping the city that was felt at the Villa Doria Pamphili was not experienced here. Being squished in-between buildings and the road, it does not filter out the noise pollution or really cool down the space as the sun was reflecting off the side of the adjacent buildings so the mentioned environmental benefits were not experienced; however, it doesn’t have many paved surfaces so as far as controlling runoff and infiltration, that benefit is still achieved. Also, the space is too small to really facilitate physical activity as far as running is concerned as this park didn’t even span a block in length.

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Figure 13: Overgrown vegetation

Considering the small size of this space from figure 14 below, the added benefits of reduced heart rate and blood pressure stemming from the reduction in noise pollution and being in a green space were not achieved. Because the space was also not maintained this added to the lackluster appeal and visual. For these reasons and those mentioned above, this would have scored rather low according to Kaplan’s matrix.

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Figure 14: Overgrown vegetation of the park and proximity to surrounding buildings

From figure 15 below, one can see also that this space isn’t being used, or at least at the time these pictures were taken. The literature outlining that green spaces can be used as a place for physical activity did not hold here, reinforcing the idea that in order for that to be achieved, there needs to be a larger area. This conclusion may not hold at other times of the day though; as this was taken during the day in the middle of the week, the people who could have taken their children to the park may have been at work or predisposed, so maybe later in the day the park could be more popular.

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Figure 15: Empty playground inside the park

While this falls low on Kaplan’s list, there are other factors to consider. When considering safety for example, the fence around the park is necessary for the children’s safety but would be a reason for its low score on Kaplan’s list considering the negative aesthetic impact. One of the criteria that Kaplan used to score these parks was mystery, but in the interest in safety mystery would need to be sacrificed. He mentions that parks that scored high were those that had winding paths that went out of view, but for young children this is not a good attribute of a play area as the guardian could lose sight of the child. Another note is that an area that was mentioned to be unfavorable on his list was one that had a large open area, but in this case that would be favorable as it would be easier to keep an eye on the children. Considering these factors, the list of characteristics that Kaplan outlines for preference do not necessarily apply to every space; some, like this one, have other utility and positive attributes that are more important than being an aesthetically pleasing or very popular site.

7. Conclusion

When considering the parks analyzed above, they represent two ends of the spectrum outlined by Kaplan’s criteria. While Villa Doria Pamphili is a sprawling estate that would be difficult to cover in a day, the playground one could cover in 5 minutes. The villa had elements put high on Kaplan’s list, including many trails that wind out of sight. As a result of its rather large size, the park felt removed from the city so one was unable to hear the traffic or surrounding city giving one the opportunity to experience the benefits of reduced noise and air pollution and consequent positive health effects. While the playground didn’t achieve the same things as the villa, it was never meant to. Focused more on safety for the children that would ultimately be playin there, it had to forgo the qualities of a park that would have scored high on Kaplan’s list. Instead of incorporating mysterious elements, it was a large clearing with good visualization, which is good for a playground where small children are present. Considering these factors, Kaplan’s outlined qualities for defining what makes a park more preferred over another does not apply to all parks, given that not all parks are intended to create the same outcome.

References

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Lanki, T., Siponen, T., Ojala, A., Korpela, K., Pennanen, A., Tittanen, P., Tsunetsugu, Y., Kagawa, T., Tyrväinen, L. (2017). Acute Effects of visits to urban green environments on cardiovascular physiology in women: a field experiment. Retrieved from https://www.sciencedirect.com/science/article/pii/S0013935116309100#bib20

Suk, J. Y., & Walter, R. J. (2019). New nighttime roadway lighting documentation applied to public safety at night: A case study in San Antonio, Texas. Sustainable Cities and Society46. Retrieved from https://www-sciencedirect-com.offcampus.lib.washington.edu/science/article/pii/S2210670718322820

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