Vulnerability of communities to climate change
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Transcript of Vulnerability of communities to climate change
1
The aim of the presentation is to discuss the vulnerability of urban
communities to climate change risks in Greater Manchester.
Dr Aleksandra Kazmierczak is a Research Associate at the University of
Manchester in the theme of Cities and Climate Change. Her particular
research interests are vulnerability of urban communities to climate change
and the role of urban greening as an adaptation response to the changing
climate.
This presentation presents findings of the research project ‘EcoCities: The
Bruntwood Initiative for Sustainable Cities’, which is a collaborative research
programme between the University of Manchester and property development
company Bruntwood.
The main aim of the project was to investigate the climate risks and the
vulnerability of different aspects of the urban environment Greater Manchester
(e.g. communities, buildings, infrastructure) to these risks, and to propose
appropriate adaptation responses (e.g. changes in urban form, institutional and
community actions).
The findings of the research project and other relevant information are
summarised on www.adaptingmanchester.co.uk.
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This presentation focuses on one aspect of the EcoCities research: the
vulnerability of communities to climate change impacts. It will explore the
climate-related risks and discuss the reasons why some people and
communities are more vulnerable than others. Then it will present the spatial
distribution of the vulnerable communities in Greater Manchester and the
associations between the level of vulnerability and the occurrence of climate
impacts. This will be illustrated by case studies at the district and
neighbourhood level. The presentation will also present some adaptation
responses that could be explored in order to minimise the climate risks to
vulnerable communities.
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One of the climate change risks that is likely to increase in the future is surface
water flooding, which is predominantly caused by short duration intense
rainfall, occurring locally. Such floods are difficult to forecast, warn against and
prepare for. The rainwater cannot infiltrate into the ground due to high
proportion of sealed surfaces (e.g. tarmac) and the urban drainage systems
often cannot cope with the amount of rainwater entering them.
The analysis of past extreme weather events through the Local Climate
Impacts Profile (LCLIP) exercise suggests that surface water flooding in
Greater Manchester may be becoming more frequent. This may be related to
the increasing proportion of sealed surfaces associated with urban
development, as well as the changes in weather patterns.
The future climate projections for Greater Manchester suggest that the rainfall
will be more concentrated: the wettest days will become even wetter. For the
large part of Greater Manchester, it is unlikely that by the 2050s (under the
high emissions scenario) the increase in rainfall on the wettest day will be
smaller than +1.4% and greater than +31%.
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Around 14% of the Greater Manchester area is susceptible to shallow surface
water flooding (up to 10 centimetres) and only around 2% of the area are at
risk of flooding up to 1 metre in depth.
The images show the proportion of Lower Super Output Areas (or LSOAs -
territorial units used in census; there are 1646 LSOAs in Greater Manchester)
at the risk of flooding. The risk of flooding is widespread: only five of 1646
LSOAs are not affected by surface water flooding. Shallow flooding is mainly
present in the south of the conurbation; deeper flooding may affect areas in
the north.
Another climate change risk is the rising temperatures in the summer.
Currently, the maximum temperature of the warmest day in summer in Greater
Manchester is 26°C. The climate change projections for Greater Manchester
suggest that by the 2050s, under the high emissions scenario, the warmest
day is unlikely to be less than 1.5°C hotter and unlikely to be more than 6°C
hotter than in the baseline scenario.
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The temperatures in cities are additionally raised by the Urban Heat Island
Effect, whereby densely built-up areas in urban centres absorb and re-radiate
more heat than areas with more vegetation.
The image presents the extent and intensity of Urban Heat Island in Greater
Manchester, shown as the deviation of surface temperatures from the average
surface temperature in Greater Manchester, and modelled for different types of
land use. The surface temperatures in the city centre can be over 2°C higher
than the average, and up to 5°C higher than in the suburbs.
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The number of heatwave events per year is likely to increase under the
changing climate. A heatwave, as defined by the UK Met Office, occurs when a
maximum temperature exceeds 30°C for two days and a minimum
temperature exceedis 15°C on the intervening night.
Climate projections for central Manchester indicate that under the high
emissions scenario for the 2050s (highlighted in yellow), there can be up to 9
heatwave events a year.
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Exposure to extreme and prolonged heat has negative impact on human health. It may cause heat cramps and heat exhaustion. Dehydration, hyperthermia and heat stroke are the most common causes of death during heat waves, followed by genital-urinary and respiratory illnesses. In Europe, the heatwave of 2003 resulted in over 80,000 additional deaths across sixteen countries. This is because in temperate regions, severe but very hot episodes during periods of generally milder weather conditions cause an increase in weather-related mortality more significant than in regions that are permanently hot.
The impacts of flooding on people include drowning and physical injuries, as well as stress and psychological trauma associated with loss of belongings, damage to property, and the necessity to move out. A loss of electricity may also impact water pumps and lead to problems with obtaining drinking water. This, combined with poor drainage, may result in diseases from the contact with water contaminated by sewage, such as diarrhoea. People living in properties that have been affected by flooding suffer from worse health and higher mortality rates.
High temperatures are associated with lower productivity and flooding can cause travel difficulties. This means that climate impacts affect not only individuals, but also entire communities and cities.
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Some people are more vulnerable to climate and weather impacts, i.e. they
are more susceptible to harm than others, due to their different capacities to
deal with hazards. Vulnerability of people to flooding is influenced by the
following four types of issues:
- Access to information: for example, the awareness of living in a flood risk
area, on knowing what to do in the event of flooding or heatwave. Access to
information can by limited for those without strong social networks, people
unfamiliar with their neighbourhood and those unable to understand the
information provided.
- Ability to prepare: for example, the ability to invest in flood insurance,
property-level flood protection measures, or electric fans and air conditioning
for heatwaves; also the physical ability to secure belongings from flooding.
- Ability to respond: knowing what to do and being able to act or receive help in
the event of heatwaves or flooding.
- Ability to recover. Some people may find it difficult to find the resources,
energy and mental strength to start again after flooding.
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The ability of people to prepare for, respond to and recover after flooding is
affected by a number of factors:
-Age: The elderly were the main victims of the 2003 heatwave. Children and
the elderly are more susceptible to health-related impacts of floods and suffer
considerable psychological trauma following flood events.
- Health: Poor health makes it more difficult to prepare for flooding and those
in poor health are more affected by heat stress. Pre-existing health problems
affect the ability of people to recover after flooding.
- Material situation: Limited income reduces the ability to invest in flood
protection measures, flood insurance or cooling systems.
- Living arrangements: Those in rented accommodation are often in the area
temporarily and may not be familiar with the local flood issues; tenants are
often unable to install adaptation measures in their accommodation. Those
living on their own can be isolated from information and help, and overcrowded
households may be more difficult to evacuate.
- Family issues: Households with dependant children may be hindered in their
preparations for the flooding by child care. Single parents may find it more
difficult to recover after flooding.
- Communication difficulaties: Those not speaking English may not
understand the information about flooding and heatwaves and the advice what
to do. Some cultural barriers to preparation to flooding, responding to heat
waves by adjusting dress and life style, or accepting help from others may
occur.
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The indicators of vulnerability corresponding with the factors listed on the
previous slide were statistically analysed at the level of Lower Super Output
Area in Greater Manchester. This helped to identify four underlying aspects of
vulnerability: Poverty and poor health, diverse communities, families with
children and the elderly. These aspects emphasise the predominant reason for
vulnerability; however, it may be accompanied by other aspects (for example,
the areas with high proportion of the elderly may also be characterised by a
high proportion of people in poor health).
On the maps, the darkest areas represent the highest vulnerability. The spatial
distribution of the different aspects of vulnerability in Greater Manchester can
be summarised as follows:
1. Areas characterised by poverty and poor health in general concentrate
around town centres, but there are also pockets of deprivation and poor
health in more suburban areas.
2. The LSOAs with high diversity of communities are even more visibly
associated with the urban centres across Greater Manchester.
3. Areas characterised by high proportion of children in the population are
more prevalent in suburban and peripheral parts of the conurbation.
4. The LSOAs with high proportion of elderly people are scattered
throughout the suburban areas of Greater Manchester.
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By overlaying the maps of vulnerability and surface water flooding it was
possible to investigate the associations between the spatial distribution of
vulnerable communities and flooding. There are no clear associations between
the level of vulnerability and the proportion of LSOA at the risk of surface water
flooding. For example, the more diverse and poorer communities tend to be
slightly more exposed to shallow flooding, but less affected deep surface water
flooding.
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Overlaying the spatial information on the vulnerability of communities and
flooding allows to identify the priority areas, where actions can be tailored to
the predominant reasons for vulnerability.
These maps show the distribution of areas at risk of shallow surface water
flooding (the blue circles represents the % of LSOA area that is susceptible to
this type of flooding) and river flooding (hatched areas) combined with the
vulnerability of communities (the background colour) in Salford. The areas
where the high vulnerability is combined with the widespread flooding should
be prioritised.
The poorer and more diverse communities tend to live in more urbanised
locations, thus are more exposed to high temperatures due to the Urban Heat
Island (UHI) effect. The graphs show that areas where the surface
temperatures are higher than the average for Greater Manchester are also
characterised by the higher vulnerability of communities due to poverty and
poor health and the diversity of communities. In particular the association
between the diversity of communities and location within the UHI is clearly
visible (the right graph).
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In Greater Manchester the communities vulnerable due to high poverty and
poor health and high ethnic and cultural diversity coincide spatially with areas
at risk of surface water flooding and higher temperatures. This calls for
adaptation measures that would limit the current weather impacts and the
future climate change risks to these communities.
The following aspects of adaptation can be considered:
-Appropriate provision of emergency services, which provide assistance during
extreme weather events;
-Community actions targeting the underlying reasons for vulnerability, such as
poverty, and improving the access to information, and the ability to prepare,
respond and recover;
-Changes in land cover, in particular in relation to urban greening, as
vegetation reduces the temperatures and helps to absorb the excess
rainwater. Also introducing surfaces reflecting heat and permeable to water
can be considered;
- Housing improvements: introduction of flood resilience measures and anti-
overheating measures.
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The more vulnerable areas in Greater Manchester are within shorter distances
from GP surgeries than the less vulnerable communities. They are also better
served by fire service and police. This means that a swift emergency services’
response in the event of flooding or heat wave is likely in these areas.
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The community actions that help to adapt to the changing climate may include
the following:
- Targeting the underlying causes of vulnerability, such as poverty, poor health
or social isolation.
- Improving the access to information for the ethnic minority groups and other
vulnerable communities. The information about the climate change risks,
recommended actions and sources of support should be presented in a
appropriate format and language.
- Supporting the networks of volunteers, who can help people to prepare for,
respond to, and recover after extreme weather events. This can include help
for the elderly (e.g. during heatwaves) or taking care of the children whilst the
parents are preparing their home for flooding.
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Green spaces help to reduce the risk of surface water flooding by absorbing
rainwater and they cool the urban environment by shading and lower
absorption and re-emission of heat than the built-up areas.
The graphs show that the poorer and more diverse communities tend to live in
areas with lower proportion of green space than wealthier and more
homogenous communities. One type of action that could be encouraged in
these areas is gardening, with an emphasis on removing the paving from front
gardens. Tree planting is valuable for shading, especially in private gardens
and on streets to the south-west of houses.
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Property level flood protection measures (flood gates, valves on sewage pipes,
raised appliances and electricity sockets) can be used in areas frequently
affected by flooding. However, they are mainly appropriate for semi- and
detached housing. The poorer and more diverse communities tend to live in
terraced housing; here street-level solutions are more appropriate, as the
water could seep from one house to another, meaning that even those
protected from flooding could be damaged. Sustainable urban drainage
systems – vegetated swales or green alleyways could be more suitable in
areas of terraced housing.
Anti-overheating measures include housing insulation (which also helps to
reduce the energy use) and shading for windows and walls to avoid heat
absorption. Using light colours on roofs and walls also reduces heat gains.
The high proportion of poor-quality housing in areas inhabited by poor and
diverse communities means that the anti-flood and anti-overheating measures
could be introduced during the general improvement works.
The areas located within the urban heat island tend to have higher proportion
of private-rented and social-rented housing. This means that working with
landlords is essential in order to introduce the anti-overheating measures.
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The diversity of communities in urban areas, combined with the variety of
housing, tenure and varying provision of green space creates a complex
picture. Successful adaptation takes this context in consideration.
This image shows a part of Manchester (Whalley Range / Moss Side), 1.4 x
1.4 km in size, inhabited by communities highly vulnerable due to high diversity
of communities, poverty and also high proportion of children and the elderly in
the population. The background colour indicates the proportion of building
walls facing south east, south or south west (they are prone to overheating).
This is combined with different types of housing present, and varying presence
of trees for shading.
The suite of adaptation measures targeted at reducing the risk of overheating
in this area will be different almost in every 200m x 200m square.
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Sources of information:
Responding to heat and social vulnerability:
http://www.adaptingmanchester.co.uk/documents/heat-and-social-vulnerability-
greater-manchester-risk-response-case-study
Surface water flooding risk to urban communities: Analysis of vulnerability,
hazard and exposure:
http://www.adaptingmanchester.co.uk/documents/surface-water-flooding-risk-
urban-communities-analysis-vulnerability-hazard-and-exposure%E2%80%99
Greater Manchester Local Climate Impacts Profile:
http://www.adaptingmanchester.co.uk/documents/greater-manchester-local-
climate-impacts-profile-gmlcip-and-assessing-manchester-city
Recent changes and trends in Greater Manchester’s climate:
http://www.adaptingmanchester.co.uk/documents/recent-changes-and-trends-
greater-manchester%E2%80%99s-climate
Climate change projections for Greater Manchester:
http://www.adaptingmanchester.co.uk/documents/climate-change-projections-
greater-manchester-version-2