Thi hinking nking Sus ustainability tainability Land Development - - PowerPoint PPT Presentation

Thi hinking nking Sus ustainability tainability

Land Development Engineering Workshop

Associate Professor Carol Boyle Civil and Environmental Engineering University of Auckland

2

Sustainability

Ensuring the needs of the current generation are met without compromising the needs of future generations

Damascus – 5000 yrs old Prague 2000 yrs old Athens – 7000 yrs old

(World Commission on Environment and Development, 1987)

3

Unsustainable Cities

Easter Island Machu Pichu Mesa Verde Ur

Goals and Assumptions for the Future

Goals

Humans will be here

Assumptions

Materials and energy will still be required Human basic needs will not have changed Community Decision Current cities will be here?

4

5

Biological Environment Climate/ Weather Hydrological Environment Chemical Environment Geological/ Geographical Environment Solar Energy Lunar Gravitation Social System

Major Recognised Global Risks

6

Global Warming Population Energy Water Biodiversity Consumption/ Waste Land Use Pollution CONFLICT

7

Urban Development – New York

Courtesy National Geographic

Megacities of Today

8

9

Land Development Risks to Sustainability

Loss of agricultural area to development, thus reducing food production Increasing population requiring increasing land space Decrease in ecosystem services to treat air and water pollution

Photo courtesy BBC news

10

Land Development Risks to Sustainability

Loss of native ecosystems reducing biodiversity and threatening species with extinction Decrease in carbon sinks in vegetation and soils

11

Land Development Risks to Sustainability

Increase in impermeable area causing increasing flood risk

12

Land Development Risks to Sustainability

Loss of life when situated in a major hazard zone (earthquake, flood, storm, volcano)

13

Land Development Risks to Sustainability

Removal of forest and plant growth causing landslips, erosion and flooding

14

Land Development Risks to Sustainability

• Flooding, sea encroachment and storm surge due to

global warming and sea level rise

15

New Orleans

16

Changes in Land Development

Prior to human settlement 75% of the land was forested Currently at 30%, with the majority of lowland converted to urban settlement, agriculture and horticulture and plantation forestry NZ species are among the most threatened in the world We also have the highest portion of land legally protected (33.4%) We have a low population and a low density – for comparison the UK and Japan have the same land mass but with populations of 80 million and 130 million respectively Our land is relatively newly cleared and still suffering from high levels of erosion – 10X faster than the rest of the world We are building in areas subject to natural hazards Our pollution levels are already locally high Much of our coastal land will be at risk due to sea level rise

Recognising the risks

• Climate change – sea level rise, storm and rainfall intensity,

increased heat loading

• Increased population and increasing development –

increased need and demand for food, water, energy, shelter

• Increased complexity of urban systems
• Increased centralisation and ‘brittleness’ of infrastructure

systems

• Increased reliance on technology
• Increased reliance on easy solutions with potential

widespread consequences

• 17

System Limits

• Our global system can be considered as an investment
• Risky strategies include
• withdrawing renewable resources faster than they are replaced (living
• ff capital rather than interest) or
• relying heavily on non-renewable, diminishing resources such as fossil

fuels (spending on items which are only useable for the short term)

• Taking more resources than a system can supply without

damage to the system results in increasing risk to the system

• Going beyond those limits by a large amount or for a long

period of time significantly increases risk to system failure

18

Resilience

• In building for hazards and sustainable systems, resilience

provides both diversity and flexibility

• Simple duplication provides redundancy but not the diversity

and flexibility

• Centralised/decentralised infrastructure systems are good

examples

• Current infrastructure economic and management models

are based on centralised systems developed in the 1800s to

• vercome a lack of wastewater, water and energy systems in

rapidly increasing cities

19

Laying London sewers, 1865

20

Courtesy BBC News UK

Cities and infrastructure today

• While such centralised systems enabled control over supply

and management of essential services, they are subject to failure under extreme events such as natural hazards and

• verloading as well as lack of maintenance
• Lock–in to existing infrastructure, management, engineering,

planning and economic models means that there is reluctance to change the system to increase resilience

• Resilient infrastructure and development is essential if we

want to reduce the risk of system or localised failure

• We also need to be more resilient in incorporating the

environment into urban areas

21

Increasing resilience and reducing risk

• Ensuring that systems are resilient and function within limits

will reduce the probability and consequences of system failure

• Redeveloping Christchurch to consider sea level rise and

storm surge will also address many of the liquifaction areas

• Providing decentralised water/wastewater services to

complement centralised systems will enable provision of services when either the local or central system fails and also reduces the pressure on those systems when they are stressed

22

Ecological systems

• Increasing the natural or living environment increases

resilience by:

• Absorbing and storing CO2 in soils and vegetation
• Reducing runoff and erosion, thus reducing siltation of local

waterbodies and risk of flooding

• Reducing risk of landslips and consequential damage
• Reduce air and water pollution
• Assisting in treating and recycling wastewater
• Moderating temperature
• Increasing biodiversity
• Improving property and community values
• Assisting in providing food in poor urban areas

23

24

Challenges

Smart cities which are population dense Increased green space within urban areas Rethinking grey urban to green urban Reconsidering urban sprawl Rethinking how we supply human needs within an urban area (energy, water, communication, transportation) Reconsidering our communities and their strengths Recognising risk from natural hazards Increasing resilience

25

Greening cities, changing transportation

26

Planning for Future Cities

Bosco Verticale, Milan (Stefan Boeri)

27

Eye on Auckland – vision for the future

Thanks to Sydney at www.eyeonauckland.com 28

Conclusions

• We need to plan our cities for the long term
• Infrastructure which operates within system limits and is

resilient will reduce risk of system failure

• Resilience includes combining centralised and decentralised

systems

• Developing systems which use the environment to provide

services such as managing wastewater, reducing pollution and stabilising land will have the greatest benefit

• Developing for sea level rise and storm surge will also assist

in protecting against liquifaction and tsunami risk

29