How Green spaces in New York City affecting its Air Quality?


Maps, Visualization

Introduction

Since the time I moved to New York City for my Masters, I was always curious and amazed by the fact that New York City being a so crowded by buildings literally like a concrete jungle, manages to have so much of open green spaces. Through this data visualization I tried to study that how much of open green spaces in form of gardens does city have and how it affects on overall environment of the city. The affects can be majored through various different parameters of which I chose the air quality as it gets affected directly by your carbon emissions and surrounding trees.

The obvious questions I had when I started my research were;

1. How does the greens affect on the air quality of the city?

and to answer this questions, I need to ask certain sub-questions such as,

Where are those gardens located in the city?

Are those gardens in small pockets or those are huge green space at center of the city and

What’s air quality around the areas where trees/green spaces are prominent, how’s air quality of those spaces different than other?

Datasets

To answer my research questions, getting enough data on greens spaces and trees in New York City was required as well data related to location wise air quality of the city was required. I thought the effective way to represent this data would be through maps as we would able to look of the exact area on map and proximity to green spaces as well.

For the same, I used QGIS to visualize my data. I used NYC shape file as a base map and used data from NYC Open Data website to collect data related to green spaces, tree plantations in NYC and air quality index.

I used datasets named as Functional Parkland as well as 2015 Street Tree Census – Tree Data to build the layers for the green spaces and trees. The another dataset I referred was about the Air quality complaints registered in NYC named as DOHMH-Indoor Environmental Complaints .

I used both data to compare effect of Green spaces on Air quality based on complaints registered by people.

Process

I started with exporting the data files and adding layers into QGIS. I added the Functional Parks in NYC vector layer on NYC map. To know the impact of green spaces I also added another layer on QGIS which was of street trees.

To map the street trees data, I had to do certain adjustments from Symbiology in QGIS to nicely represent that on maps.

The another two datasets were inserted in QGIS based on the longitudes and latitudes columns given in the data file of Air Quality Complaints. To represent these layers separately, I need to again do certain alterations from Symbiology, duplicate the layer and then change the category which I wanted to represent.

To come up with final outcome, I kept scale constant which was 1:125000 for all different layers and exported the images in high resolution format.

Results

The overall findings were little surprising than what I thought they would be. Even though NYC especially Manhattan region has lot of gardens/green pockets compared to other big cities, it still needs to improve so that there would be less air quality concerns. The city needs to have more green pockets to cater to the huge daily visitors and to improve air quality as that directly impacts on the health of the people in that area.

Below displayed is the map of NYC-Manhattan region with functional parklands/green pockets. We could see where exactly the green spaces are located and the density of the gardens.

1.1 NYC-Manhattan region with Functional Parklands/Gardens highlighted in Green scale1:125000

To add to this information, I referred to the the another data of street trees as trees also contribute and impact when it comes to air quality. The small yellowish green colored lines shows the trees those are planted in NYC across the roads.

1.2 NYC-Manhattan region with layer of street trees in yellow scale-1:125000

Moving further, we could see that there are ample no of trees along the roadside but lesser gardens in Manhattan area. We need to see further how it impacts on the air quality and hence I referred to the air quality complaints data which is represented in the map below.

1.3 NYC-Manhattan region with air quality complaints highlighted by purple triangle scale-1:125000

The map above illustrates air quality complaints in the NYC-Manhattan region, represented by purple-colored triangles. It is evident that Manhattan exhibits the highest concentration of air quality complaints compared to other areas.

To explore the correlation between green spaces and air quality, I am conducting a comparative analysis of both maps. This examination aims to discern whether the presence of green spaces genuinely influences the air quality in New York City or if other predominant factors are primarily responsible for the observed air quality patterns.

1.2 NYC-Manhattan region with trees
1.3 NYC-Manhattan region with air quality complaints

Observing the data, it becomes apparent that Queens and Brooklyn, characterized by a higher number of medium-sized green spaces, register fewer air quality complaints compared to Manhattan. The latter, with predominantly one large green pocket and fewer, smaller ones, exhibits a higher incidence of air quality issues.

This marked contrast in air quality concerns prompted me to delve deeper into potential contributing factors. One prominent and widely considered factor was population density. Given Manhattan’s notably high population, I sought to collect comprehensive population data for New York City to enhance the precision of my conclusions.

1.4 NYC-Manhattan region census tract scale-1:125000

After understanding the living population of the NYC-Manhattan region, we need to compare both the maps of census vs complaints while gathering our study conclusions.

1.5 The interactive comparison between the census tract and the air quality complaints

Based on the above analysis, it is evident that, despite the fact that areas with a high census tract exhibit fewer air quality complaints, a noteworthy observation emerges when contrasting them with green areas. Specifically, regions characterized by a greater number of substantial green pockets tend to experience fewer air quality complaints.

Census Tract
Air Quality Complaints
Green spaces

From the above three maps we can see that street trees are planted citywide but green pockets are more found in queens, Brooklyn and upper Manhattan area. Even though Central Manhattan has a huge pocket of Central park its effect on surroundings is very minimum. Although central and lower Manhattan has lesser population living there, we need to consider other factors such as carbon footprint of that region which also includes the building density in the city, no of daily visitors and other activities going on in that area. Transportation options in that area can be one of the criteria.

Reflections

The use of maps for representation of the green spaces and air quality data is very appropriate and helped me conclude better. While I was doing the visualization few of my peers suggested me to look for the population aspect as well as the street trees and green pockets vary a bit but air quality complaints very a lot in Manhattan region as compared to Brooklyn and Queens region. This was the helpful insight which could shape my conclusions.

I feel that comparing other datasets such as daily no of visitors or carbon footprint or building density would have gathered me even more detailed and thoughtful insights hence I’m planning to implement that further.

References

Data, City of New York, NYC Open. “NYC Open Data.” http://nycod-wpengine.com/.

“Welcome to the QGIS Project!” https://qgis.org/en/site/.

“Functional Parkland Map | NYC Open Data.” Accessed December 5, 2023. https://data.cityofnewyork.us/Recreation/Functional-Parkland-Map/r2ng-2bhg.

NYC Open Data. “2015 Street Tree Census – Tree Data.” Accessed December 5, 2023. https://data.cityofnewyork.us/Environment/2015-Street-Tree-Census-Tree-Data/pi5s-9p35.

“DOHMH Indoor Environmental Complaints | NYC Open Data.” Accessed December 5, 2023. https://data.cityofnewyork.us/Health/DOHMH-Indoor-Environmental-Complaints/9jgj-bmct.