Vulnerability of communities to climate change


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This presentation was given by Dr Aleksandra Kazmierczak on the 20th June 2012.

The aim of the presentation was to discuss the vulnerability of urban communities to climate change risks in Greater Manchester.

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Vulnerability of communities to climate change

  1. 1. 1The aim of the presentation is to discuss the vulnerability of urbancommunities to climate change risks in Greater Manchester.Dr Aleksandra Kazmierczak is a Research Associate at the University ofManchester in the theme of Cities and Climate Change. Her particularresearch interests are vulnerability of urban communities to climate changeand the role of urban greening as an adaptation response to the changingclimate.
  2. 2. This presentation presents findings of the research project ‘EcoCities: TheBruntwood Initiative for Sustainable Cities’, which is a collaborative researchprogramme between the University of Manchester and property developmentcompany Bruntwood.The main aim of the project was to investigate the climate risks and thevulnerability of different aspects of the urban environment Greater Manchester(e.g. communities, buildings, infrastructure) to these risks, and to proposeappropriate adaptation responses (e.g. changes in urban form, institutional andcommunity actions).The findings of the research project and other relevant information aresummarised on
  3. 3. 3This presentation focuses on one aspect of the EcoCities research: thevulnerability of communities to climate change impacts. It will explore theclimate-related risks and discuss the reasons why some people andcommunities are more vulnerable than others. Then it will present the spatialdistribution of the vulnerable communities in Greater Manchester and theassociations between the level of vulnerability and the occurrence of climateimpacts. This will be illustrated by case studies at the district andneighbourhood level. The presentation will also present some adaptationresponses that could be explored in order to minimise the climate risks tovulnerable communities.
  4. 4. 4One of the climate change risks that is likely to increase in the future is surfacewater flooding, which is predominantly caused by short duration intenserainfall, occurring locally. Such floods are difficult to forecast, warn against andprepare for. The rainwater cannot infiltrate into the ground due to highproportion of sealed surfaces (e.g. tarmac) and the urban drainage systemsoften cannot cope with the amount of rainwater entering them.The analysis of past extreme weather events through the Local ClimateImpacts Profile (LCLIP) exercise suggests that surface water flooding inGreater Manchester may be becoming more frequent. This may be related tothe increasing proportion of sealed surfaces associated with urbandevelopment, as well as the changes in weather patterns.The future climate projections for Greater Manchester suggest that the rainfallwill be more concentrated: the wettest days will become even wetter. For thelarge part of Greater Manchester, it is unlikely that by the 2050s (under thehigh emissions scenario) the increase in rainfall on the wettest day will besmaller than +1.4% and greater than +31%.
  5. 5. 5Around 14% of the Greater Manchester area is susceptible to shallow surfacewater flooding (up to 10 centimetres) and only around 2% of the area are atrisk 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 1646LSOAs are not affected by surface water flooding. Shallow flooding is mainlypresent in the south of the conurbation; deeper flooding may affect areas inthe north.
  6. 6. Another climate change risk is the rising temperatures in the summer.Currently, the maximum temperature of the warmest day in summer in GreaterManchester is 26°C. The climate change projections for Greater Manchestersuggest that by the 2050s, under the high emissions scenario, the warmestday is unlikely to be less than 1.5°C hotter and unlikely to be more than 6°Chotter than in the baseline scenario.6
  7. 7. The temperatures in cities are additionally raised by the Urban Heat IslandEffect, whereby densely built-up areas in urban centres absorb and re-radiatemore heat than areas with more vegetation.The image presents the extent and intensity of Urban Heat Island in GreaterManchester, shown as the deviation of surface temperatures from the averagesurface temperature in Greater Manchester, and modelled for different types ofland use. The surface temperatures in the city centre can be over 2°C higherthan the average, and up to 5°C higher than in the suburbs.7
  8. 8. The number of heatwave events per year is likely to increase under thechanging climate. A heatwave, as defined by the UK Met Office, occurs when amaximum temperature exceeds 30°C for two days and a minimumtemperature exceedis 15°C on the intervening night.Climate projections for central Manchester indicate that under the highemissions scenario for the 2050s (highlighted in yellow), there can be up to 9heatwave events a year.8
  9. 9. Exposure to extreme and prolonged heat has negative impact on humanhealth. It may cause heat cramps and heat exhaustion. Dehydration,hyperthermia and heat stroke are the most common causes of death duringheat waves, followed by genital-urinary and respiratory illnesses. In Europe,the heatwave of 2003 resulted in over 80,000 additional deaths across sixteencountries. This is because in temperate regions, severe but very hot episodesduring periods of generally milder weather conditions cause an increase inweather-related mortality more significant than in regions that are permanentlyhot.The impacts of flooding on people include drowning and physical injuries, aswell as stress and psychological trauma associated with loss of belongings,damage to property, and the necessity to move out. A loss of electricity mayalso impact water pumps and lead to problems with obtaining drinking water.This, combined with poor drainage, may result in diseases from the contactwith water contaminated by sewage, such as diarrhoea. People living inproperties that have been affected by flooding suffer from worse health andhigher mortality rates.High temperatures are associated with lower productivity and flooding cancause travel difficulties. This means that climate impacts affect not onlyindividuals, but also entire communities and cities.9
  10. 10. 10Some people are more vulnerable to climate and weather impacts, i.e. theyare more susceptible to harm than others, due to their different capacities todeal with hazards. Vulnerability of people to flooding is influenced by thefollowing four types of issues:- Access to information: for example, the awareness of living in a flood riskarea, on knowing what to do in the event of flooding or heatwave. Access toinformation can by limited for those without strong social networks, peopleunfamiliar with their neighbourhood and those unable to understand theinformation provided.- Ability to prepare: for example, the ability to invest in flood insurance,property-level flood protection measures, or electric fans and air conditioningfor 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 inthe 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.
  11. 11. 11The ability of people to prepare for, respond to and recover after flooding isaffected by a number of factors:-Age: The elderly were the main victims of the 2003 heatwave. Children andthe elderly are more susceptible to health-related impacts of floods and sufferconsiderable psychological trauma following flood events.- Health: Poor health makes it more difficult to prepare for flooding and thosein poor health are more affected by heat stress. Pre-existing health problemsaffect the ability of people to recover after flooding.- Material situation: Limited income reduces the ability to invest in floodprotection measures, flood insurance or cooling systems.- Living arrangements: Those in rented accommodation are often in the areatemporarily and may not be familiar with the local flood issues; tenants areoften unable to install adaptation measures in their accommodation. Thoseliving on their own can be isolated from information and help, and overcrowdedhouseholds may be more difficult to evacuate.- Family issues: Households with dependant children may be hindered in theirpreparations for the flooding by child care. Single parents may find it moredifficult to recover after flooding.- Communication difficulaties: Those not speaking English may notunderstand the information about flooding and heatwaves and the advice what
  12. 12. to do. Some cultural barriers to preparation to flooding, responding to heatwaves by adjusting dress and life style, or accepting help from others mayoccur.11
  13. 13. 12The indicators of vulnerability corresponding with the factors listed on theprevious slide were statistically analysed at the level of Lower Super OutputArea in Greater Manchester. This helped to identify four underlying aspects ofvulnerability: Poverty and poor health, diverse communities, families withchildren and the elderly. These aspects emphasise the predominant reason forvulnerability; however, it may be accompanied by other aspects (for example,the areas with high proportion of the elderly may also be characterised by ahigh proportion of people in poor health).On the maps, the darkest areas represent the highest vulnerability. The spatialdistribution of the different aspects of vulnerability in Greater Manchester canbe summarised as follows:1. Areas characterised by poverty and poor health in general concentratearound town centres, but there are also pockets of deprivation and poorhealth in more suburban areas.2. The LSOAs with high diversity of communities are even more visiblyassociated with the urban centres across Greater Manchester.3. Areas characterised by high proportion of children in the population aremore prevalent in suburban and peripheral parts of the conurbation.4. The LSOAs with high proportion of elderly people are scattered
  14. 14. throughout the suburban areas of Greater Manchester.12
  15. 15. 13By overlaying the maps of vulnerability and surface water flooding it waspossible to investigate the associations between the spatial distribution ofvulnerable communities and flooding. There are no clear associations betweenthe level of vulnerability and the proportion of LSOA at the risk of surface waterflooding. For example, the more diverse and poorer communities tend to beslightly more exposed to shallow flooding, but less affected deep surface waterflooding.
  16. 16. 14Overlaying the spatial information on the vulnerability of communities andflooding allows to identify the priority areas, where actions can be tailored tothe predominant reasons for vulnerability.These maps show the distribution of areas at risk of shallow surface waterflooding (the blue circles represents the % of LSOA area that is susceptible tothis type of flooding) and river flooding (hatched areas) combined with thevulnerability of communities (the background colour) in Salford. The areaswhere the high vulnerability is combined with the widespread flooding shouldbe prioritised.
  17. 17. The poorer and more diverse communities tend to live in more urbanisedlocations, thus are more exposed to high temperatures due to the Urban HeatIsland (UHI) effect. The graphs show that areas where the surfacetemperatures are higher than the average for Greater Manchester are alsocharacterised by the higher vulnerability of communities due to poverty andpoor health and the diversity of communities. In particular the associationbetween the diversity of communities and location within the UHI is clearlyvisible (the right graph).15
  18. 18. 16In Greater Manchester the communities vulnerable due to high poverty andpoor health and high ethnic and cultural diversity coincide spatially with areasat risk of surface water flooding and higher temperatures. This calls foradaptation measures that would limit the current weather impacts and thefuture climate change risks to these communities.The following aspects of adaptation can be considered:-Appropriate provision of emergency services, which provide assistance duringextreme weather events;-Community actions targeting the underlying reasons for vulnerability, such aspoverty, 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, asvegetation reduces the temperatures and helps to absorb the excessrainwater. Also introducing surfaces reflecting heat and permeable to watercan be considered;- Housing improvements: introduction of flood resilience measures and anti-overheating measures.
  19. 19. 17The more vulnerable areas in Greater Manchester are within shorter distancesfrom GP surgeries than the less vulnerable communities. They are also betterserved 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.
  20. 20. 18The community actions that help to adapt to the changing climate may includethe following:- Targeting the underlying causes of vulnerability, such as poverty, poor healthor social isolation.- Improving the access to information for the ethnic minority groups and othervulnerable communities. The information about the climate change risks,recommended actions and sources of support should be presented in aappropriate 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 helpfor the elderly (e.g. during heatwaves) or taking care of the children whilst theparents are preparing their home for flooding.
  21. 21. 19Green spaces help to reduce the risk of surface water flooding by absorbingrainwater and they cool the urban environment by shading and lowerabsorption and re-emission of heat than the built-up areas.The graphs show that the poorer and more diverse communities tend to live inareas with lower proportion of green space than wealthier and morehomogenous communities. One type of action that could be encouraged inthese areas is gardening, with an emphasis on removing the paving from frontgardens. Tree planting is valuable for shading, especially in private gardensand on streets to the south-west of houses.
  22. 22. 20Property level flood protection measures (flood gates, valves on sewage pipes,raised appliances and electricity sockets) can be used in areas frequentlyaffected by flooding. However, they are mainly appropriate for semi- anddetached housing. The poorer and more diverse communities tend to live interraced housing; here street-level solutions are more appropriate, as thewater could seep from one house to another, meaning that even thoseprotected from flooding could be damaged. Sustainable urban drainagesystems – vegetated swales or green alleyways could be more suitable inareas of terraced housing.Anti-overheating measures include housing insulation (which also helps toreduce the energy use) and shading for windows and walls to avoid heatabsorption. Using light colours on roofs and walls also reduces heat gains.The high proportion of poor-quality housing in areas inhabited by poor anddiverse communities means that the anti-flood and anti-overheating measurescould be introduced during the general improvement works.
  23. 23. The areas located within the urban heat island tend to have higher proportionof private-rented and social-rented housing. This means that working withlandlords is essential in order to introduce the anti-overheating measures.21
  24. 24. The diversity of communities in urban areas, combined with the variety ofhousing, tenure and varying provision of green space creates a complexpicture. Successful adaptation takes this context in consideration.This image shows a part of Manchester (Whalley Range / Moss Side), 1.4 x1.4 km in size, inhabited by communities highly vulnerable due to high diversityof communities, poverty and also high proportion of children and the elderly inthe population. The background colour indicates the proportion of buildingwalls facing south east, south or south west (they are prone to overheating).This is combined with different types of housing present, and varying presenceof trees for shading.The suite of adaptation measures targeted at reducing the risk of overheatingin this area will be different almost in every 200m x 200m square.22
  25. 25. 23
  26. 26. 24Sources of information:Responding to heat and social vulnerability: water flooding risk to urban communities: Analysis of vulnerability,hazard and exposure: Manchester Local Climate Impacts Profile: changes and trends in Greater Manchester’s climate: change projections for Greater Manchester: