Thi hinking nking Sus ustainability tainability Land Development Engineering Workshop Associate Professor Carol Boyle Civil and Environmental Engineering University of Auckland
Sustainability Ensuring the needs of the current generation are met without compromising the needs of future generations Prague 2000 yrs old Damascus – 5000 yrs old (World Commission on Environment and Development, 1987) Athens – 7000 yrs old 2
Unsustainable Cities Easter Island Machu Pichu Ur Mesa Verde 3
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
Solar Lunar Energy Gravitation Geological/ Climate/ Geographical Weather Environment Biological Hydrological Environment Environment Chemical Environment Social System 5
Major Recognised Global Risks Energy Global Water Warming Consumption/ Biodiversity CONFLICT Waste Population Land Use Pollution 6
Urban Development – New York Courtesy National Geographic 7
Megacities of Today 8
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 9
Land Development Risks to Sustainability Loss of native ecosystems reducing biodiversity and threatening species with extinction Decrease in carbon sinks in vegetation and soils 10
Land Development Risks to Sustainability Increase in impermeable area causing increasing flood risk 11
Land Development Risks to Sustainability Loss of life when situated in a major hazard zone (earthquake, flood, storm, volcano) 12
Land Development Risks to Sustainability Removal of forest and plant growth causing landslips, erosion and flooding 13
Land Development Risks to Sustainability Flooding, sea encroachment and storm surge due to • global warming and sea level rise 14
New Orleans 15
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 16
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 • off 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 overcome a lack of wastewater, water and energy systems in rapidly increasing cities 19
Laying London sewers, 1865 Courtesy BBC News UK 20
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 overloading 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 CO 2 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
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 24
Greening cities, changing transportation 25
Planning for Future Cities 26
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
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