what are the environmental issues associated with urban change.pptx

7/27/2019 What are the environmental issues associated with urban change.pptx

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What are the environmental issues

associated with urban change?


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Urban change can put increasing pressures on

the environment including:

Traffic congestion

Atmospheric pollution

Water pollution

Waste disposal

Urban dereliction


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Objectives for this topic

At the end of this topic you should be able to:

Explain the links between urban change and theresulting environmental issues.

Describe the main impact of these environmentalissues.

Outline the challenges involved in managingthese environmental issues

Identify some examples of attempts to reduce theimpact of urban change on the environment.


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The Brown Agenda Launched by UN in 1992 at same

time as Rio Earth Summit

Drew attention to consequences of development andurban growth on built environments. Major issuesraised

Lack of safe water, sanitation and sewage disposal(drainage)

Inadequate management of solid and hazardous waste.

Incidence of traffic, industrial and environmental

accidents. Uncontrolled emissions into the atmosphere.

The occupation of unsafe land by shanty towns.


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Water

Water is essential for human survival and for urban growth.

Water demand is rising in most areas. What do we use itfor? Why do you think MEDCs use more water than LEDCs?

Major problem is that urban water supplies are readily

contaminated by industrial waste, sewage and pollutioncarried in urban runoff. In rural areas agricultural practicessuch as applying manure and artificial fertilisers can lead tolethal chemicals seeping into reservoirs and groundwaterstores.

It is difficult to collect and store water to ensure acontinuous supply during long dry seasons.


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Problems with a high demand for

water:

Cities such as London and Mexico are slowly

sinking as the groundwater is being removed

allowing underlying rocks to compress. M.C.

has subsided by 7m since 1940.

Increased areas of land are given over to

reservoirs e.g. The Lea Valley in London.

Water is transported ever greater distances so

potentially depriving the source area.


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Waste

Urban areas create huge quantities of solid

waste, particularly in MEDCs due to increasing

consumption and throwaway societies.

Recycling waste is the obvious solution but it

is not always done to its full potential due to

cost and technological reasons.

The challenge remains as to what to do with

non-recyclable waste, particularly toxic waste.


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Waste problems for urban centres:

Difficulties in locating and establishing landfillsites.

Pollution from landfill sites (methane and

groundwater pollution). Very high cost.

High transportation costs and the resulting air

pollution (traffic fumes) Risk of vermin and disease from rubbish

waiting to be collected.


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Comparison of waste production

MEDCs and LEDCsMEDC LEDC

Waste per person (kg/year)

composed of

800-1200 100-340

Organic matter 10% 75%

Paper 25% 2%

Plastics 35% 2%

Glass 15% 3%

Metals 10% 3%

Others 5% 15%


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Traffic and Transport

The movement of people and goods is a vitalaspect of urban areas.

The more efficient the movement the better it

is for the environment and the people. Three specific issues can be identified with

this

Traffic congestion Oil consumption

Public vs Private transport


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Traffic congestion

A major feature of most modern urban areas.

Caused by a range of factors including:outdated road networks, rise in cars,

concentration of jobs and services in the core. Resulting problems include: waste of time and

fuel, pollution, noise, stress, danger to

pedestrians, accidents. Paratransit is a major problem in many LEDC

citiesParatransit: mode of transport which does not

follow fixed routes or timetables e.g. Rickshaws,

minibuses, pedicabs. A major part of the informal

economy in LEDC cities


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Possible solutions to traffic congestion

problems

Segregation

Parking

Vehicle control Public transport

Traffic Information systemsHowever, these solutions are more likely to

prove effective in MEDC than LEDC citiesdue to the high incidence of paratransit in

LEDCs.


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Air pollution

Has been reduced in MEDCs due to deindustrialisation and

clean air legislation but has shifted to LEDCs.

Major polluters are:

Vehicles

Industry

Power stations

Domestic heating

Major concerns are the effects on :Human health and wildlife

Contribution to global warming


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The 3 main pollutants causing serious risk to human health are

suspended particles (soot, smoke, dust and liquid particles),

sulphur dioxide and nitrogen oxide

Pollutant Effects on health

Sulpher dioxide and smoke Potential health effects include temporary respiratory in

sensitive groups exposed to high levels for short periods

and an increased prevalence of respiratory problems for

long term exposure.

Nitrogen dioxide Acute exposure can cause transient respiratory problems:

children and asthmatics are at greatest risk.

Ozone High levels increase susceptibility to infections and

respiratory disease; can cause irritation of eyes, nose and

throat, chest discomfort, coughs and headaches.

Carbon monoxide Reduces oxygen supply to the body, impairing physical

coordination, vision and judgment; affects central nervous

and cardiovascular systems; those with heart disease are at

most risk


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The net results of air pollution are as follows: Increase in number of deaths (est 8000 per year in Delhi).

Increase in rates of lung disease (40% more cases of

pneumonia occur in people living near motorways inEngland).

Expensive hospitalisation.

Absence from work.

Dirty buildings = Increased cleaning costs.

Smogs. Acid rain

Greenhouse effect.

General environmental damage to a range of vegetation.


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Urban dereliction and Brownfield sites.

Derelict land is an old name for areas now called Brownfield sites. These

are areas where buildings have been abandoned. They are often in a state

of disrepair.

Urban areas are dynamic and frequently changing, one negative effect of

this dereliction which has 3 main contributory causes:

Inevitable ageing and decay of buildings with the passage of time.

Movement of urban activities to better and more profitable locations

Basic changes in an urban economy brought about by the collapse of

certain notable activities.

Dereliction is often a temporary phase and much derelict land is

reclaimed for things like housing, tourism, industry etc.

Can you think of any examples?


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http://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=tjS5nszXGF7aIM&tbnid=n8ZLF1XVfK_8qM:&ved=0CAUQjRw&url=http://www.bbc.co.uk/nature/habitats/Brownfield_land&ei=qI9KUoHDB8iW0AWo74GgDg&bvm=bv.53371865,d.d2k&psig=AFQjCNHXOSCA74E7cVc-HGQ_yt8qt98uAw&ust=1380704541278458


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Brownfield: Land previously used for urbandevelopments e.g. Factories, terraced housing etc.

The government prefers the use of Brownfield sites fornew developments. This means they regularly financeEnterprise Zones

In England government policy is that 60% of all newhomes should be built on Brownfield land

Can you foresee any problems with this idea?

Brownfield sites Greenfield sites


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Brownfield sites Greenfield sites

Derelict sites in urban areas New sites, usually on agricultural land in green

belts around urban areas.

The land is available, but can be costly to

reclaim if it has been polluted by industrial

use; this information may not be readily

available.

Land is not available unless planning

permission has been obtained; there will

usually be a public enquiry and a delay of

several years which will add to costs.

Housing is likely to be built at high density to

reflect the cost of the land; there is less

demand for such housing as it is in less

fashionable areas.

Housing will be at a relatively low density

compared with brownfield sites; there is a

great demand for such housing as it is in

fashionable areas.

Infrastructure is usually present, though

existing facilities can become overloaded.

Infrastructure costs are high as new sewerage,

water, gas and electricity supplies have to be

considered; similarly new schools and medicalfacilities may be needed.

Sites tend to be small patches of land. Sites tend to be large.

The environment is improved. The environment is harmed.

Existing services close by. New service provision is required.


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Tasks Make a list of the issues involved that make using brownfield sites

difficult or unpopular.

Read the information on building on the floodplain (pg 199) andoutline the key issues.

Complete the London and Mumbai comparison activity. (pg 202)

Read the case studies in the topic 3 booklet: The environmentalissues associated with urban change. You should be looking at CarShare and BART in San Francisco, Reducing air pollution and The

New East Manchester Plan. Make appropriate notes so that you canremember the key points to use as examples in exam questions.


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For each of the categories you will need to produce a

fact file. It should include the following:

A range of visual material showing the problems.

2 contrasting cities, one MEDC city and one LEDC

city.

Show how these pressures/problems effect the

quality of life of people who live in the cities by

looking at the environmental, social and economic

implications.


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Specific city websites can be used to identify a

range of issues.

General websites such as:

www.un.org (UN- millennium goals)

www.urbanicity.org (citiesonline/europeancities)

May be a useful starting point
http://www.un.org/http://www.urbanicity.org/http://www.urbanicity.org/http://www.un.org/


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Issues associated with traffic

congestion:

Wikipedia Mexico City, Los Angeles,

Bangkok.

Google BART (Transport management)

www.nexus.org.uk (Tyne and Wear metro)

www.metrolink.co.uk (Manchester metro)

www.tfl.gov.uk (Transport management inLondon)

www.bbc.co.uk (traffic congestion)
http://www.nexus.org.uk/http://www.metrolink.co.uk/http://www.tfl.gov.uk/http://www.bbc.co.uk/http://www.bbc.co.uk/http://www.tfl.gov.uk/http://www.metrolink.co.uk/http://www.nexus.org.uk/


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Issues associated with atmospheric

pollution

Wikipedia Mexico City, Los Angeles, Sao

Paulo, Bangkok.

http://www.worldbank.org/en/topic/urbandevelopment (urban

problems).
http://www.worldbank.org/en/topic/urbandevelopmenthttp://www.worldbank.org/en/topic/urbandevelopmenthttp://www.worldbank.org/en/topic/urbandevelopment


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Issues associated with water pollution:

Wikipedia Cairo, Sao Paulo, Bangkok

www.worldbank.org (urban problems)

www.wateraid.org.uk
http://www.worldbank.org/http://www.wateraid.org.uk/http://www.wateraid.org.uk/http://www.worldbank.org/


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Issues associated with waste disposal

Wikipedia Cairo, Sao Paulo, Bangkok.

Google managing waste


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Issues associated with urban

dereliction

Wikipedia Mexico City, Sao Paulo, Bangkok.

www.worldbank.org (slums, self help

schemes, urban problems)

www.urbansplash.co.uk (regeneration of

derelict industrial sites in the UK).
http://www.worldbank.org/http://www.urbansplash.co.uk/http://www.urbansplash.co.uk/http://www.worldbank.org/

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