Prof Ni-Bin Chang presented the background review of New York City case study. Flood impact assessment in mega cities under urban sprawl and climate change kick-off workshop

1. Flood Impact Assessment in Mega Cities under
Urban Sprawl and Climate Change (Part II)
Ni-Bin Chang, Ph.D., P.E.
Director, Stormwater Management Academy
University of Central Florida
July 6, 2015

2. Outline
• Introduction to New York City: a Mega City
• Important city planning projects relating to flood
management
• Smart growth perspectives

3. Population Growth
• As of July 2014, New York City’s population was estimated at
8,491,079 by the U.S. Census Bureau.
• This represented an increase of 315,900 residents (or 3.9
percent) over the April 2010 decennial census count of
8,175,133.
• Population growth was fueled by the continued surplus of
births over deaths due to life expectancy in the city, coupled
with a net influx of people into the city.

4. New York City: a Mega City
Source: Department of Planning, NYC

5. Population Distribution in 2013
New York City's five boroughs overview
Jurisdiction Population Land area
Borough County
1 July 2013
Estimates
square
miles
square
km
Manhattan New York 1,626,159 23 59
The Bronx Bronx 1,418,733 42 109
Brooklyn Kings 2,592,149 71 183
Queens Queens 2,296,175 109 283
Staten Island Richmond 472,621 58 151
City of New York 8,405,837 303 786
State of New York 19,651,127 47,214 122,284
Source: US Census Bureau

6. Population Gain over the last 51 Months
• Each of the city’s five boroughs registered gains in population.
• Brooklyn saw the largest increase, up 4.7 percent or 117,100
persons
• Queens (4.1 percent or 90,900 persons)
• Bronx (3.8 percent or 53,100 persons)
• Manhattan (3.2 percent or 50,400 persons)
• Staten Island (1.0 percent or 4,500 persons) period.
Source: US Census Bureau

7. Geographical
Environment of NYC
• Hudson River estuary
waterways around New
York City:
1. Hudson River,
2. East River,
3. Long Island Sound,
4. Newark Bay,
5. Upper New York Bay,
6. Lower New York Bay,
7. Jamaica Bay, and
8. Atlantic Ocean.
Source: Department of City Planning,

8. Population Growth (blue) and Population Loss (red)
from 1990 to 2000
Source: wikipedia

9. Geograpgic Distribution of Median Income in NYC

10. Important City Planning Projects
Relating to Flood Management
• Flood management : National Flood Insurance Program
• Green infrastructure plan
• Skyway plan
• Bicycle track plan
• Public transportation access and rezoning
• New York City comprehensive waterfront plan
• World Trade Centre reconstrcution plan
Source: Department of City Planning, NYC

11. Risk & Resilience: A Systems Approach for Water Security

12. Future Flood Zones for New York City
• New York City Panel on Climate Change Climate Risk
Information 2013 Observations, Climate Change Projections,
and Maps (JUNE 2013).
• The maps at right show future flood zones for the area taking
into account sea level rise from both ocean warming and ice
sheet melt.
• They factor in local conditions such as vertical land movement
and regional climate variations.

13. Future 100-Year and 500-Year
Flood Zones for New York City
NYCC2

14. FEMA 100-year Floodplain: Bronx and Brooklyn
Bronx Brooklyn

15. FEMA 100-year Floodplain: Queens and Staten Island
Queens Staten Island

16. FEMA 100-year Floodplain: Manhattan
Manhattan
Sources: New York City Panel on Climate Change
Climate Risk Information 2013 Observations, Climate Change
Projections, and Maps

17. Projected Future 100-year Floodplain
- 2013, 2020, and 2050
• If mid-century projections of
sea level rise prove true for
New York City, four times as
many people may be living
in the 100-year floodplain
than were previously
estimated based only on
observed changes.

18. Trend Detection in Sea Level Anomalies
Source: Possible sea-level rise with varying scenarios (NASA, 2014)

19. Tropical Cyclone
• A tropical depression is an organized system of clouds and
thunderstorms with a defined surface circulation and
maximum sustained winds of 38 miles per hour or less.
• A tropical storm is an organized system of clouds and
thunderstorms with a defined surface circulation and
maximum sustained winds of 39 ~ 73 miles per hour.
• A hurricane is an organized system of clouds and
thunderstorms with a defined surface circulation and
maximum sustained winds of 74 miles per hour or greater.

20. Hurricane Sandy Inundation via Storm Tidal Surge
Surces: NYC

21. Storm Surge Height, Wave Run-up, Storm Tide, and Tide

22. Distribution of NFIP Policy Claims

23. Estimated Sandy 1 m Hindcast on Feb. 2014

24. Storm Tide in NYC
Category 4
Category 3
Category 2
Category 1

25. New York City Storm Surge Innudation Zone

26. Rotterdam Flood Barrier in New York City
http://inhabitat.com/

27. New York City Green Infrastructure
McPhearson et al., 2014

28. Low Impact Development (LID)
Stormwater Pond
Rain Graden
Green Roof
Pervious Pavement

29. New York City Green Infrastructure
Right-of-way Bioswale, Denton Place, Brooklyn
Proposed green street

30. How Do Low Impact Development (LID) Technologies Come to
Help?
# Introduce a spatially-explicit
approach to assist landscape
architects, urban planners, and
water managers in identifying
priority sites for LID.
# Examine the current flood
proofing facilities to public utility
department in identifying priority
sites in response to sea level rise,
storm surge, and storm tides.

31. New York City Green Infrastructure
Original and Expanded Priority
CSO Tributary Areas in 2014
Original and Expanded Priority
CSO Tributary Areas in 2015

32. New York City Green Infrastructure
Projected construction start dates for
area-wide green infrastructure contracts
in 2014
Projected construction start dates for
area-wide green infrastructure contracts
in 2015

33. Impacts of Public Transportation Access on Real Estate
Development in New York City, New York

34. New York City Comprehensive Waterfront Plan

35. East River Skyways

36. Est River Bicycle Tracks

37. World Trade Centre Reconstruction Plan

38. Smart Growth

39. Challenges in Synergistic Research
• Integration between storm tidal surge model and urban
growth model
• Integration between socioeconomical development, land
demand, and urban growth model
• Integration between low impact development, stormwater
management, and flood impact assessment model.