CUE 3237 Flashcards
Define dereliction.
Dereliction refers to the state of buildings/ an area having been abandoned and become dilapidated.
What are the causes of dereliction?
- ageing and decay
- outmigration
- loss of industry
- impact from past planning decisions
Outline “ageing and decay” as a factor causing dereliction.
Buildings age and decay with time.
Pre-war buildings are expensive to maintain. Owners may be unwilling to pay for maintenance and tenants may move out.
Housing quality can also decline if there’s an increase in population density.
Outline “outmigration” as a factor causing dereliction.
If skilled people move away, a lower skilled and less qualified population remain and the area will become less conomically active.
Outline “loss of industry” as a factor causing dereliction.
Urban activities may move to better and more profitable locations.
In the UK, deindustrialisation led to many people leaving the inner city and industrial buildings being abandoned.
Services e.g. pubs and shops may become vacant as these areas become subject to urban decline.
Outline “impact from past planning decisions” as a factor causing dereliction.
For example, narrow streets and a lack of infrastructure were among the issues that led to a lack of investment in the London Docklands until the LDDC developed the area.
What are the impacts of dereliction?
- higher rates of crime and vandalism
- house prices fall
- out migration of residents
- health risks from contamination from industrial processes in an environment remains long after the industry that produced them is gone
- high costs involved in urban renewal often discourage authorities / individuals from renovation or rebuilding
What are the strategies to deal with derelict urban areas?
Regeneration schemes. Government led schemes eg UDCs, City Challenge and New Deal for Communities have had varying levels of success.
The government focus on using brownfield sites for new building developments rather than greenfield sites which has been successful.
London had the greatest proportion of dwellings built on brownfield sites at 98%.
Advantages of using brownfield sites in urban areas?
- improves physical environment
- existing infrastructure reduces costs & encourages faster occupancy
- preserves historical landmarks and heritage architecture
- revives older communities
- reduces urban sprawl and preserves greenfield land
Disadvantages of using brownfield sites in urban areas?
- not all brownfield sites have the physical access necessary for residential development
- the neighbouring land may still be used for industrial purposes, making the brownfield site unsuitable for new homes
- most brownfield sites are in inner city areas, which have high levels of pollution, congestion, noise
- 1000s of brownfield sites may already have been contaminated by previous industrial uses and may present significant risks to human health and the wider environment. Decontamination is time consuming and expensive.
What is land remediation?
The removal of pollution or contaminates from the ground.
This enables large areas of derelict former land to be brought back into commercial use.
CASE STUDY: DERELICTION.
DETROIT.
- it was once the centre of global car production
- but globalisation increased and business moved to Asia
- population fell from 2m in the 1950s to 1m
- 1/3 of its land area was derelict
- BUT, between 1970 and 2000 150,000 buildings were demolished and larger commercial developments built to try to revitalise the area
- decline continued. Became known as “rust belt”
- HOWEVER community groups are now using the land for small, community based activities including urban farming
- by 2010 they had turned 7 hectares of unused land into over 40 community gardens and micro farms
Define water pollution.
The contamination of water bodies or sources including rivers, lakes, oceans, aquifers, groundwater. It occurs when pollutants are directly or indirectly discharged into the water without adequate treatment to remove harmful compounds.
When is water seen as polluted?
When it can no longer support human use eg drinking. Or there’s a shift in the ability to sustain aquatic life.
Indirect sources of water pollution include…
Contaminants that enter the water from soils or groundwater and from the atmosphere via rain.
The high concentration of impermeable surfaces in urban areas increases runoff from roads and can carry various pollutants eg oils, heavy metals, rubber.
How many people die due to water pollution?
14,000 people per day.
Causes of water pollution in urban areas?
- surface runoff from streets carrying oil, heavy metals.
- industrial waste.
- untreated / poorly treated sewage which is low in dissolved oxygen and high in pollutants eg nitrates, bacteria.
- rubbish dumps, toxic waste which can all leak pollutants.
- intentional dumping of hazardous substances.
- air pollution can lead to acid rain, nitrate deposition and ammonium deposition which can alter the water chemistry of an area.
Consequences of water pollution in urban areas?
- heavy metals from industrial processes can slow development, result in birth defects and may be carcinogenic.
- organic matter and nutrients can cause an increase in aerobic algae and deplete oxygen from the water. This can lead to the suffocation of fish.
- suspended particles in freshwater reduces the quality of drinking water for humans and the aquatic environment for marine life. They can also reduce the amount of sunlight penetrating the water, disrupting the growth of photosynthetic plants and microorganisms.
- microbial pollutants from sewage often result in infectious diseases that infect aquatic and terrestrial life through drinking water. Microbial pollution causes diseases eg cholera, typhoid which are a major cause of infant mortality in low income countries.
What is the ideal way of managing water pollution?
Preventing pollutants from entering the water course in the first place but this cannot always happen.
In most high income countries, water quality improvement focuses on two approaches:
- The construction of water treatment facilities and waste water plants.
- Regulations aimed ‘at point’ polluters such as industries which discharge water pollution into receiving waters or sewer systems that flow into treatment plants.
What is the most difficult water quality challenge?
Dealing with ‘non point source’ pollution which is the result of precipitation runoff from a wide range of sources eg fertilisers and toxins from urban areas.
Why is water quality standards lower in low income countries?
Because of a lack of money and inadequate technology.
What are the key water pollution strategies?
- LIDs (Low Impact Developments).
- legislation, regulation and enforcement
- education and awareness
- improvements in sewage and waste water processing
- appropriate technology
Explain LIDs as a strategy to control water pollution.
Low Impact Development is a storm water management approach that can help to reduce storm water runoff. This is done primarily through the use of vegetation and permeable surfaces to allow infiltration into the ground.
Permeable streets and pavements, green roofs, rain gardens and urban parks allow water to infiltrate into the soils rather than flow directly into sewers.
This strategy has been shown to reduce organic pollutants, oils and heavy metals by 90%
