Maximizing urban services in Valdivia, Chile with green infrastructure
Elizabeth M Cook and Olga Barbosa,
Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia
Intentional planning with green infrastructure
may mitigate effects of changing climate
Natural hazards and humans change green
infrastructure in Valdivia
2012: Replaced the
2015-2030: predicted
Cites are increasingly threatened by climate change. Integrating gray
(e.g. built) and green (e.g. wetlands) infrastructure may increase the
resilience of cities and urban populations to extreme weather events.
1960: 9.5 magnitude
earthquake off coast of
Valdivia caused 90%
increase in wetlands
and natural flood
protection for city
Gray (built) infrastructure
Green infrastructure
Fail-safe approach minimizing
chances of failure
Safe-to-fail approach minimizing
consequences of failure
High efficiency solutions with
single purpose design
Leverages existing natural resources
to provide multi-functional services
Habitat &
Water quality biodiversity
regulation
Flood
regulation
Educational
value
Carbon storage
& sequestration
Aesthetic &
recreation
value
Thermal
regulation
Air quality
regulation
Habitat &
Water quality biodiversity
regulation
Flood
regulation
Aesthetic &
recreation
value
Percent Change
60
40
unitary (combined)
sewage & rainwater
1990-2010: 55%
system with separate
urban growth and
little regulations led systems using
to infill of wetlands integrated grey &
green infrastructure
for development
and ~70 flood events
30% urban growth &
subsequent loss of
wetlands with business
as usual development
Based on goals in the Sustainability Plan and predicted 30% population
growth by 2030, we developed and assessed 3 future scenarios for Valdivia
with different strategies for protecting green space and increasing density.
20
0
-20
Built
Wetlands
Grassland
Trees
-40
-60
1940 1950 1960 1970 1980 1990 2000 2010 2020 2030
1983
1961
1943
2010
2010: Existing
development
Carbon storage
& sequestration
Thermal
regulation
T. Miller (PSU)
Valdivia: a case study of green infrastructure
Increasing
urban
density
Figure 2: After a significant increase in wetlands following the 1960 9.5 magnitude earthquake,
rapid urbanization and lack of development regulations led to the infill and decline of natural
wetlands in the city. Historically, wetlands were valued more as cheap land for development
and waste disposal than for their ecological value. Recently, however, wetlands have been
acknowledged in planning documents as valuable flood protection.
Zone 1
Zone 2
Zone 3
Zone 4
Valdivia
Assessing multiple ecosystem services over
time and space
A. Year
Image: NordNordWest
Figure 1: Valdivia, Chile is ~850km south of Santiago. The city is situated ~15km
from the Pacific Ocean at the confluence of three rivers. Several neighborhoods
(Zones 1 - 4) are at high risk for flooding and loss of natural wetlands due to rapid
development. These areas also house citizens of the lowest socio-economic status.
City population: 165,000
Business as Usual
1943
1961
1983
2010
Flood 1
regulation
B. Urban Area
Habitat
area
Zone 1
Zone 2
Zone 3
Zone 4
1
1
0
Carbon
storage
Flood 1
regulation
Habitat
area
Mean annual precipitation: >1870 mm High/low temperature: 72/40
Ecosystem: Biodiversity hotspot in Valdivian temperate rainforest
1
Thermal
regulation
1
Protecting Wetlands
Smart Growth
Flood 1
regulation
1
Thermal
regulation
1
1
0
Habitat
area
1
Carbon
storage
City vulnerabilities: Precipitation and tidal flooding, summer drought,
lack of planning regulations and resources, earthquakes, and landslides.
oF
2030: “Protecting
wetlands” scenario
Moderate regulations
implemented to
protect wetlands from
infilling for
development
2030: “Smart
growth” scenario
Optimal scenario to
increase urban
density in strategic
urban hubs and
protect green space
Multi-criteria assessment of future scenarios as
planning and decision support tool
2010
2030 Scenarios
To quantify impacts of urbanization, we modeled indicators of ecosystem
services including flood and temperature regulation, habitat area, and carbon
storage across years (Fig 3A) and vulnerable neighborhoods (Fig 3B). These
indicators highlight increasing vulnerabilities to climate change and
extreme events as green infrastructure and ecosystem services decline
over time and in the most vulnerable neighborhoods (e.g. Zone 3).
Santiago
2030: “Business
as usual” scenario
No restrictions on
sprawl or future
development,
including continued
infill of wetlands
The optimal “smart growth” scenario may provide greater thermal
regulation, carbon storage and habitat area than other futures, but
have lower flood regulation potential. This highlights the importance of
assessing the tradeoffs of multiple services and the need to intentionally
integrate both green and gray infrastructure in future planning.
Latin American cities are particularly vulnerable to climate change and
extreme events due to rapid urban development, dense populations,
outdated infrastructure, and limited resources.
We assessed historic and future change in green infrastructure in
Valdivia, Chile as a means to mitigate the effects of extreme
events through the provision of multiple ecosystem services.
The recently published Valdivia Sustainability
Plan of Action for 2030 highlights normative
social, economic and environmental goals for a
shared future, including targeted actions to
protect natural wetlands.
Inter-American Development Bank & Initiative for Emerging and Sustainable Cities (ICES) 2015
Educational
value
Air quality
regulation
Planning for the future in 2030 to protect green
infrastructure and reduce vulnerabilities
1
Thermal
regulation
Figure 3: Indicators of ecosystem service provision modeled (A) over time and (B) in 2010 urban
neighborhoods most vulnerable to flooding (see Fig 1). All indicators are standardized on 0 (low
provision) - 1 (high) scale for comparability. Median flood regulation (runoff potential based on avg
12mm rain event), thermal regulation (evapotranspiration and emissivity), carbon storage (tree C
storage), and habitat area (% green space) estimated in 6.25 ha grid cells across the urban region.
Carbon
storage
Figure 4: Multi-criteria
assessment of indicators
of ecosystem service
provision of habitat area,
carbon storage, and
temperature and flood
regulation in 2010 and 3
future scenarios for 2030
(Business as usual,
Protecting wetlands, and
Smart growth scenarios).
Ecosystem service
indicators same as Fig 3.
Next steps toward co-production of desirable
future scenarios and cross city comparisons
We plan to co-produce and assess additional desirable future scenarios
with local stakeholders in order to feed into local planning.
We hypothesize that Latin American cities may be more reliant on green
infrastructure than North American cities, but incorporate it less formally in
municipal planning. Thus green infrastructure will be undervalued in Latin
American cities for potential to improve ecosystem services. We plan to
compare cities across a diversity of social-biophysical contexts and
vulnerabilities to future extreme events (flooding, heat, drought).
Acknowledgements: Many thanks to Javiera Maira (Activa Valdivia), Alexandra Castañeda, Cristóbal García, Karina Godoy, Daniel Harris,
Valeria Ochoa (UACh), and David Iwaniec and Nancy Grimm (ASU). This project is based on support by CONICYT-FONDECYT Projects:
3150290 (Postdoctorado),11110183 & FONDAP: 15110020.
References: Hansen & Pauleit 2014, ICES 2015, Rojas 2006, Shaffler & Swilling 2013, UN Habitat 2012