Planning for the Ecocity

Transcription

1 Planning for the Ecocity Stephan Pauleit Professor in Strategic Landscape Planning and Management The city is a pattern of built and open spaces downloaded

2 Challenges Reduce ecological footprint Improve environmental quality Mitigate & adapt to climate change Urbanization: a one-way process Land take from nature and agriculture Artificial surfaces Land returned to nature and agriculture 1 Mill. ha 16 0,1 Mill. ha Billion ha +5 % Source of data: Corine Land Cover Surveys, 1990 &

3 Urban sprawl in Europe European cities have expanded on average by 78% since the mid-1950s The population has grown by only 33% EEA 2006 Jansson et al Projections for urban land use 2025 Nilsson

4 Urbanization on the edges of existing agglomerations Randstad, NL Leipzig - Halle, DE Urban density & energy consumption Fuel consumption (GJ/ person) Urban density (persons per hectare) after Newman & Kenworth

5 Urban sprawl should be avoided Photo: G. Jørgensen but there are also limits to urban compaction 5

6 The urban heat island effect EPA 2003 Pluvial flooding Photo: Greve Municipality 6

7 difference in runoff coefficient 1975/2000 Scotland Road Wavertree Tranmere Woolfall Heath Prescot Southport Claughton Sherdley Park Moreton Orrell Birkdale Impacts of infill densification - Merseyside, UK Photos: Y. Golding Increase of stormwater runoff Pauleit et al.,

8 Climate change hits cities hard Concentration of people & economy Location in risk zones, e.g. coastal areas, floodplains, slopes Heat island intensified Stormwater runoff increased 70,000 excess deaths resulting from heat wave in Europe in 2003 (Robine et al. 2007) Climate change impacts - Greater Manchester Temperatures on a hot summer day in C Gill 2006, Gill et al Low density residential: +3,1 C Town centre: +4,3 C 8

9 Vulnerability of people & places Lindley 2009 Importance of the public realm 9

10 Urban Morphology of Greater Manchester Surface cover in Greater Manchester Evapotranspiring surfaces Built surfaces 10

11 Max surface temp (deg C) Max surface temp (deg C) Evapotranspiring proportion Surface temperatures: Closely related to green cover town centre retail manufacturing distribution & storage high density residential energy production & distribution refuse disposal major roads rail offices hospitals airports medium density residential mineral workings & quarries low density residential schools disused & derelict land water storage & treatment unimproved farmland allotments UMT cemeteries & crematoria formal open space formal recreation improved farmland informal open space remnant countryside river, canal woodland Gill et al. 2007, Gill 2006 max surface temp evaporating fraction Effect of adding/subtracting greenspace on surface temperature C 1970s 2020s Low 2020s High 2050s Low 2050s High 2080s Low C C 2080s High C Time period and emissions scenario town centre town centre -10% green town centre +10% green 11

12 Trees reduce heating & cooling demands Photo: John F. Handley 12

13 Stormwater runoff 56% more precipitation: 82% more runoff Surface runoff (mm) Sources: Gill 2006, Gill et al GM infiltration capacity A case for soil conservation areas? 13

14 Hydrological and climatic functions of the green infrastructure Corridors Patches Matrix Retention Infiltration Evapotranspiration Matrix Shading Adapted from: Gill et al Potential conflict between mitigation and adaptation Compact city Green city 14

15 Responses - urban planning and design Compaction and greening Regional planning Public transport Soft mode transport Mixed use, walkability and public space Green infrastructure Photo: Ole Malling Regional planning: Copenhagen Fingerplan Compaction along fingers To preserve green infrastructure 15

16 Coordination between transport & land use Coordination between transport and land use Soft mode transport Green infrastructure planning - City of Stockholm Green map as a tool for land use planning: Biotope map Recycling map (nutrients, runoff water, waste water, energy plantations, shelterbelts) Sociotope map COST Action C8 16

17 Selected ABC Ecosystem Services = ecological processes/functions of the green infrastructure Abiotic Biotic Cultural Surface:groundwater interactions Soil development processes Maintenance of hydrological regime(s) Accommodate disturbance regime(s) Habitat for generalist, and specialist species Species movement routes and corridors Supports metapopulation dynamics Maintenance of disturbance and successional regime(s) Integral and supportive of economic activity Opportunity for physical recreation Experience and interpretation of cultural history Provide a sense of solitude and inspiration Buffering of nutrient cycling Biomass production Healthy context for social interactions Storage/Sequestration of Carbon Reservoir of genetic diversity Stimulus for artistic and abstract expression Modification, buffering of climatic extremes Support of flora:fauna interactions Environmental education Ahern 2007 Munich: One Green Ring for All Sale on farms Allotments on farmland Promotion of site adapted farming: Cattle in fenlands Sheep on heathlands 17

18 Ecological land banking - Munich 67 ha Restoration of a fenland area New urban-rural relationships - Management of flows 21st century: Recreation Organic waste? Renewable energy? Climate? Flood & stormwater? 19th century: Night soil in Copenhagen 18

19 Intermunicipal cooperation: Heathland Society & Fenland Society Compact & green urban development - Munich: Urban Strategy compact, urban, green Reiß-Schmidt,

20 Mixed mode development - Messestadt Riem on former airfield Messestadt Riem on former airfield 20

21 Biotope area factor - a planning tool City of Berlin 21

22 Integration of multifunctional GI in built areas Augustenborg, Malmø Bjølsen studentby, Oslo Visible solutions create synergies but there are also unknown risks Jensen

23 Three points approach Impacts Geldof 2005 & 2007 Conclusions Key issue: balance between compact and green city Linking regulatory and informal approaches Green infrastructure can act as a bridge between ecology and planning GI provides essential ecosystem services and adaptive capacity to climate change Green = 100% GI planning should promote Strategic, long-term orientation Multifunctionality Connectivity Integration Communicative and socially-inclusive planning and management Importance of (pilot) projects How to deal with complexity and uncertainty in planning? 23