Mapping Climate Change Vulnerability in NYC - A GIS Group Report - Columbia GSAPP

MAPPING CLIMATE CHANGE VULNERABILITY IN NYC

Christine Ghossoub, Jade Watkins, Gizem Karagoz

GIS Fall 2018 Final Project

MS Urban Planning

Columbia University GSAPP

WHEREAS, we all have a moral, economic, public health, and security imperative to act to protect our planet, fellow human beings, and future generations; and WHEREAS, the many benefits of climate action by cities also address issues of inequality including the expanding wealth gap, the lack of housing, the Waccessibility of public transit, aging infrastructure, and other major urban challenges; and WHEREAS, President Donald Trump's decision to pull out of the Paris Agreement puts millions of Americans at risk and cities like New York City must step up to stop climate change.

NOW, THEREFORE, by virtue of the power vested in me as Mayor of the City of New York, it is hereby ordered: Commitment to Principles and Goals of Paris Agreement NYC 1.5 Climate Action Plan Executive Order 26 Signed June 2, 2017

Table of contents 01

introduction

03

scope + limitations

06

methodology

08

environmental indicators

10

social indicators

12

access to resources

14

decision maps

17

analysis

25

conclusion

27

sources

Introduction 1.5ď‚°C Climate Action Plan, enacted by executive action in 2017, aligns New York City with the goals of the Paris Climate Agreement. This climate change policy outlines strategies to mitigate greenhouse gas emissions and build resiliency against the projected impacts of climate change. Regionally, New York City will face increased sea levels, flooding, and stronger weather events.

Recent storms such as Hurricane Sandy are indicators of the frequency and extent of this potential risk.

The impacts of climate risk disproportionately affect various neighborhoods across New York City. This risk is based on each community's adaptive capacity: the socio-economic characteristics which enable the community to cope with the impacts of climate change. Therefore, in order to efficiently and effectively respond to climate risk, neighborhoods that have the highest vulnerability levels must be identified. For the scope of this GIS analysis, climate change vulnerability is operationalized as the compounded impact of environmental hazards, socio-economic factors and access to resources.

This study will identify vulnerable neighborhoods and compare them with those highlighted in the Resilient Neighborhoods initiative by the NYC Department of City Planning in 2013 (updated in 2017). The Resilient Neighborhoods initiative is based solely on flood plains, which represents a single aspect of our analysis. The aim of this GIS process is to advocate for a comprehensive analysis of climate change vulnerability by utilizing several spatial analyses methods and a holistic set of criteria.

1

Vulnerability Data Layers flood risk

environmental indicators

air pollution levels heat vulnerability

+ social indicators

access to resources

2

median household income youth and elderly population limited English proficiency transportation public facilites

Scope The scope of this project focuses analyses on climate change vulnerability for New York City's five boroughs based on multiple factors that contribute to climate change vulnerability. These factors are identified from previous research, as either additive or subtractive factors for climate change vulnerability. The most recent data for three different data categories are used to determine the most vulnerable census tracts: environmental data, sociodemographic data, and "resources" data. Within the environmental data category, three individual data sets are included to represent climate change vulnerability: potential flooding, urban heat index, and air pollution. All three data sets are provided

by New York City departments. From the United States Census Bureau, the American Community Survey, 2012-2016 five year range, serves as the data source for sociodemographic data.The five year range is used in this analysis as it is more accurate than a single year dataset and not intended to focus on a specific year. Within sociodemographic data, the specific fields used are: age under 18 and above 75 years old, language English ability as "less than very well," and median income. All of the sociodemographic data was initially joined and mapped to New York City's 2010 census tracts.

Further analysis for other climate change vulnerability layers also was performed and compared at the census tract level. "Resources" data sets for New York City spatially represent varying levels of "access" to support against climate change vulnerability.These data sets are continuously updated by the NYC Open Data site and the most current versions will be used. The three data sets used are bus stops, subway stations, and a selection from the New York City Department of City Planning's Facilities Database. The facilities selected include public facilities as well as specific facilities identified as resources to mitigate the effects of climate change.

Limitations Data limitations included the Heat Index data provided by the New York City Department of Health and Mental Hygiene (NYC DOHMH). The data provided by the DOHMH was previously indexed by the department's definition of heat vulnerability. This definition included sociodemographic factors to some extent. Therefore, some of the analysis represents double counting for sociodemographic variables. Time presented another limitation. Datasets were not ordered from outside sources and only data that was readily downloadable from online public sources was used.

With respect to analysis performed, another limitation is data may be generalized when aggregating environmental, sociodemographic, and resources layers to an overall climate change vulnerability decision map. The focus for the analysis aimed to identify which census tracts are most vulnerable to climate change based on several factors. Analyses that focus on specific climate vulnerability factors are represented in individual maps throughout this report. The final decision maps represent the aggregated layers in order to provide a comprehensive analysis to climate change vulnerability.

3

4

Research Questions Which census tracts in New York City have the most significant levels of climate change vulnerability due to compounded environmental and socio-economic factors, while considering spatial access to resources?

How do the identified vulnerable census tracts in New York City compare to the areas focused in the Resilient Neighborhoods initiative?

5

Methodology

                 





  

 

            

    

 

6





















 



 



 















    









 

 

  

   

  

      

  

  

  

  

   7

Environmental Indicators

flood risk

air pollution levels

heat vulnerability  

 

Reviewing the information provided by the individual flood risk, air pollution, and heat vulnerability analysis layers above, different regions are represented at a greater risk for environmental climate change factors. Interestingly, much of the greatest risk areas in each analysis layer are not repeated consistently across all three layers. Flood risk accordingly represents the areas with greatest risk to flooding for projected sea level rise. Air pollution represents a combination of the top five air pollutants from data provided by the New York City Community Air Survey. These air pollutants included nitrogen dioxide, fine particulate matter, black carbon, nitric oxide, and summer average for ozone. For air pollution, Manhattan and its radiating areas represent the majority of vulnerability to air pollution. Also, evaluating the air pollution analysis layer, high vulnerability to air pollution stretches out across the outer boroughs in what is hypothesized to be transit lines with heavy car traffic. Finally, for the heat vulnerability analysis layer, significant portions of the Bronx and Brooklyn are designated as highly vulnerable to heat.

A ranked decision map was created from the reclassification of the environmental vulnerability factors to create an overall decision map for environmental vulnerability to climate change. This decision map, visualized on the right, represents analysis layers for flood risk, air pollution, and heat vulnerability aggregated with all environmental factors being considered equal for this part of the analysis. It is important to note the most vulnerable areas to environmental factors of climate change in New York City are not restricted to coastlines, but instead, are spread across the city with more vulnerable areas present in the Bronx and Brooklyn.

8

 

                





  

 

 





 



 





    Reclassified  Raster Map of   All Environmental Indicators







 

 





  

  





 

  

 

  









  

 

 

environmental indicators







   



social indicators

 

  

  

  

  

  

 

access to resources

9

Social Indicators

median income

% youth and elderly population

% speaks "English less than very well"  

 

All of the sociodemographic data was provided by the United States Census Bureau through the American Community Survey. From previous research, the three variables listed above represent critical social factors to the effects of climate change. Median income displays Manhattan as the least vulnerable, with surrounding boroughs, particularly the Bronx and Brooklyn as more vulnerable to climate change based on median income. Age was a combination of the percent of youth and elderly populations, detailed as under 18 and above 75 years old. Interestingly, Manhattan, Staten Island, and the southern coastal edge of Queens are considered less vulnerable. Language was visualized by percent that identified speaks "English less than very well." Few regions of New York City stood prominently as more vulnerable in terms of English language speaking ability.

A ranked decision map was created from the reclassification of the sociodemographic vulnerability factors to create an overall decision map for socio-demographic vulnerability to climate change.This decision map, visualized to the right, represents analysis layers for median income, age, and language vulnerability aggregated with all sociodemographic factors being considered equal for this part of the analysis. For this category of the analysis, the most vulnerable areas to climate change are visualized in the Bronx, southern Brooklyn, and a few spread census tracts across the rest of Brooklyn and Queens.

It is important to note that not all neighborhoods identified by New York City's Resilient Neighborhoods initiative are represented when sociodemographic factors relating to climate vulnerability are taken into account.

10





 





 



 

 





  





    



Reclassified Raster Map of All Social Indicators







 

 

  

   

  

      

  

  

  

  

  

 

environmental indicators

social indicators

 

access to resources

11

Access to Resources

public facilities

sunway stops

bus stops  

 

Access to resources was considered the third category of data for this analysis of climate vulnerability and included in order to try and develop a comprehensive outlook. Bus stops and subway stations were included as access to transportation resources. Other resources were selected from the New York City Department of City Planning's facilities database. Within this database, two intentional selections were made. First, public facilities were selected to distinguish between public and private access. Second, facilities were selected based on their potential to mitigate the impacts of climate change. Bus stops, subway stations, and facilities were merged together to output New York City resources against climate change.

With the merged dataset, a kernel density map was created in order to sample the density of points with respect to their spatial location to one another.

This process aggregated various resources to output an overall perspective of access to resources across New York City's five boroughs, visualized to the right. Darker color represents greater density of resources. Notice, Manhattan, northern Brooklyn, and souther Bronx all have the highest density of resources.

Later, towards our final decision maps, access to resources will be subtracted from this analysis' vulnerability equation.

12

  







    









Reclassified Kernel Density Map of All Resource Facilities

 



 







      





  

  

  

  

  

 

environmental indicators

social indicators

 

access to resources

13

Weighted Decision Map 1

Ranked Map 0.67 - 22.75

0

22.75 - 27.17

0 - 90

27.17 - 29.81

90 - 123

29.81 - 32.50

123 - 153

32.50 - 35.21

153 - 176

35.21 - 37.73

176 - 195

37.73 - 40.00

195 - 217

40.00 - 42.60

217 - 243

42.60 - 46.18

243 - 274

46.18 - 56.38

274 - 375

Layer

Number of Classes

Rank

Layer

Number of Classes

Weight

Flood risk Air pollution level Heat vulnerability Median Income Age Lanugage Resources

1 - 10 1 - 10 1 - 10 1 - 10 1 - 10 1 - 10 1 - 10

1 1 1 1 1 1 1

Flood risk Air pollution level Heat vulnerability Median Income Age Lanugage Resources

1 - 10 1 - 10 1 - 10 1 - 10 1 - 10 1 - 10 1 - 10

10 10 10 5 5 5 3

Max score:

480

Max score:

14

70

Weighted Decision Map 2 The overall analysis to climate change vulnerability produced a set of three decision maps. The first was a ranked decision map in which each of the seven criteria were considered equal. The second decision map was a weighted decision map in which vulnerability to the environmental factors of climate change was given greater preference by more heavily weighting flood risk, air pollution, and heat vulnerability. Sociodemographic factors were given less preference for this map, and therefore, less weight. The purpose of this was to identify any areas that presented a somewhat greater risk to climate change vulnerability when environmental factors were given greater preference within the overall aggregated map. The third decision map was another weighted decision map in which sociodemographic vulnerability was given greater preference by more heavily weighted median income, age, and language.

Environmental factors were given less preference for this map, and therefore less weight. The purpose of this map was to pose an opposite comparison to the first weighted map in which environmental vulnerability was given greater weight. These three decision maps present how even with the same data, vulnerability can be visualized differently based on the weights and thereby, preference given to each analysis layer.

0 0 - 63 63 - 135 135 - 169 169 - 197 197 - 221 221 - 249 249 - 283 283 - 320 320 - 420

Layer

Number of Classes

Weight

Flood risk Air pollution level Heat vulnerability Median Income Age Lanugage Resources

1 - 10 1 - 10 1 - 10 1 - 10 1 - 10 1 - 10 1 - 10

5 5 5 10 10 10 3

Max score:

480

environmental indicators

Interestingly, much of the most vulnerable areas across New York City are consistently displayed in all three decision maps. Notice in each of the decision maps, the Bronx, south Brooklyn, northeast Brooklyn, and various other areas represent the most vulnerable areas to climate change based on this analysis.

Individual differences would be representative of their specific vulnerability within each of the analysis layers and weights given.

social indicators

access to resources

15

As a subsequent comparison to overall aggregation of climate vulnerability layers, two areas are chosen for further analysis. Both of these resulted in high vulnerability scores based on the methodology within this analysis.

One of the areas also represents a neighborhood identified by the Resilient Neighborhoods initiative, the other does not.

While the Resilient Neighborhoods initiative only assesses flood risk, the other area represents vulnerability to climate change for all three of our main analysis categories.

South Brooklyn provides an example of a highly vulnerable area corresponding to the Resilient Neighborhoods initiative and the Bronx provides an example of an area identified by this analysis when a comprehensive approach to climate change vulnerability is taken into account.

16

environmental indicators

social indicators

access to resources

17

Top 20% Vulnerable Census Tracts Average Indicator Stats by Borough

The twenty percent most vulnerable census tracts were isolated from the weighted map preferencing sociodemographic vulnerability to climate change. These census tracts were used to compare to New York City's Resilient Neighborhoods initiative.

Average Population by Borough

% Speaks English Less than Very Well

% of population that is youth and elderly

Average Median Income by Borough

18

Number of Vulnerable Census Tracts by Borough the Bronx Brooklyn Queens Manhattan Staten Island

153 103 25 4 0

environmental indicators

socio-demographic indicators

access to resources

19

Comparison with Resilient Neighborhoods corresponding areas

% of population that is youth and elderly

% Speaks English Less than Very Well

Average Median Income by Borough

Facilities Points Residential Land Use Vulnerable Census Tracts

flood risk

Average Demographics of Most Vulnerable Census Tracts

air pollution levels

heat vulnerability

20

total population

3999 people

% youth and elderly population

34%

% limited English proficiency

52%

median household income

$16,861

% census tract flooded

62.9%

air pollution level

6.6

heat vulnerability score

2.7

density of facilities in vulnerable census tracts: 0.07 facilities per acre

The south Brooklyn area presented an example of an area identified by the Resilient Neighborhoods initiative, and is also considered one of the most vulnerable for this analysis. Notice the analysis layers to the left display the variation for vulnerability within each layer of our resulting decision maps. Darker colors for these six maps represent greater vulnerability. Locations of resources are displayed below the Resilient Neighborhoods reference map. More detailed numbers in the table to the left provide a helpful perspective.

Interestingly, for the census tracts in the south Brooklyn area, flood risk was present, but so were several other factors related to the overall vulnerability score.

2 -149 149 - 179 179 - 206 206 - 225 225 - 244 244 - 264 264 - 283 283 - 302 302 - 333 333 - 400

the top 20% of the most vulnerable Census Tracts follow within a score range of 320 -400

environmental indicators

socio-demographic indicators

access to resources

21

Comparison with Resilient Neighborhoods non-corresponding areas

% of population that is youth and elderly

% Speaks English Less than Very Well

Average Median Income by Borough

Facilities Points

flood risk

Residential Land Use Vulnerable Census Tracts

Average Demographics of Most Vulnerable Census Tracts

air pollution levels

heat vulnerability

22

total population

4736 people

% youth and elderly population

32%

% limited English proficiency

32%

median household income

$16,464

% census tract flooded

7.2%

air pollution level

6.4

heat vulnerability score

4.5

density of facilities in vulnerable census tracts: 0.1 facilities per acre

The Bronx area presented an example of an area not recognized by the Resilient Neighborhoods initiative, but is considered one of the most vulnerable for this analysis. Notice the analysis layers to the left display the variation for vulnerability within each layer of our resulting decision maps. Darker colors for these six maps represent greater vulnerability. Locations of resources are displayed below the Resilient Neighborhoods reference map. More detailed numbers in the table to the left provide a helpful perspective.

Interestingly, for these census tracts, flood risk was not present, but other prominent factors made the area more vulnerable overall for climate change.

2 -149 149 - 179 179 - 206 206 - 225 225 - 244 244 - 264 264 - 283 283 - 302 302 - 333 333 - 400

the top 20% of the most vulnerable Census Tracts follow within a score range of 320 -400

environmental indicators

socio-demographic indicators

access to resources

23

24

Conclusion The full geospatial analysis reveals some similarities between areas the Resilient Neighborhoods initiative identifies as at risk to climate change and groups of census tracts identified through this analysis. But several census tracts identified using a holistic approach to climate change were not represented at all in the Resilient Neighborhoods initiative. Because this initiative only takes into account risk to flooding, other vulnerability aspects can present a completely different picture.

The results of this analysis support a more comprehensive approach to identifying and addressing climate change vulnerability. It is important to keep in consideration, that the results from the ranked and weighted decision maps represent an aggregation of three categories to climate change vulnerability. Past climate change vulnerability research often assesses one category alone, and in-depth analysis such as these present detailed information. The purpose of this analysis intended to visualize vulnerability to climate change by incorporating not only environmental factors, but also sociodemographic variables and access to resources.

For future analyses, projects, development, and consideration, it is imperative to consider not only the environmental factors of climate change vulnerability, but also sociodemographic variables and access to resources.

25

Sources New York City Department of City Planning. 2017. LION v17A. [ESRI File Geodatabase]. 19 November 2018. https://www1.nyc.gov/site/planning/data-maps/open-data/dwn-lion.page.

New York City Department of City Planning. "Neighborhood Tabulation Areas - ArcView Shapefile" [shapefile]. Bytes of the Big Apple - Archive. Release 18B. 2018. https://www1.nyc.gov/site/planning/datamaps/open-data/bytes-archive.page?sorts[year]=0&queries[search]=Neighborhood+tabulation+area.

New York City Department of City Planning. "New York City Census Blocks for 2010 US Census" [shapefile]. Bytes of the Big Apple, Issue 18C. 13 August 2018. https://www1.nyc.gov/site/planning/ data-maps/open-data/districts-download-metadata.page.

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New York City Open Data. "2010 Census Tracts" [shapefile]. New York City Department of City Planning, created 20 June 2014, updated 19 September 2018. https://data.cityofnewyork.us/CityGovernment/2010-Census-Tracts/fxpq-c8ku.

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New York City Open Data. "NYCCAS Air Pollution Rasters," [dataset]. Department of Health and Mental Hygiene, created 11 May 2017, updated 10 September 2018. New York City Department of Health and Mental Hygiene. https://data.cityofnewyork.us/Environment/NYCCAS-Air-PollutionRasters/q68s-8qxv.

New York City Open Data. "New York City Council Districts" [shapefile]. New York City Department of City Planning Facilities Database. 10 September 2018. https://data.cityofnewyork.us/City-Government/ Facilities-Database-Shapefile/2fpa-bnsx.

New York City Open Data, "Subway Stations" [shapefile]. Metropolitan Transportation Authority, created 10 April 2013, updated 10 September 2018. https://data.cityofnewyork.us/Transportation/ Subway-Stations/arq3-7z49.

US Census Bureau. 2016 American Community Survey, 5-Year Estimates. Table S0601: Selected Characteristics of the Total and Native Populations of the United States by census tract, New York County, New York State. [dataset]. Accessed via American FactFinder. 2016. https://factfinder.census. gov/faces/tableservices/jsf/pages/productview.xhtml?pid=ACS_16_5YR_S0601&prodType=table.

environmental indicators

Christine Ghossoub, Jade Watkins, Gizem Karagoz

social indicators

GIS Fall 2018 Final Project

MS Urban Planning

access to resources

Columbia University GSAPP