Mapping and visualizing urban form urban intensification analysis for New Zealand cities

Transcription

1 Mapping and visualizing urban form urban intensification analysis for New Zealand cities Dr Pengjun Zhao Postdoctoral researcher New Zealand Centre for Sustainable Cities The 14 th Public Health Summer School, Growth misconduct? Can we do better on urban intensification, 16 February, 2010, Department of Public Health, University of Otago

2 Contents Definitions Gross density analysis Comparison with Australia cities Net density of Wellington Region Discussion Next step

3 Definitions Density: key element of urban form and local environmental management Population density: people per unit area Gross density: area density including all types of land use Net density: area density excluding non-built-up land use (green space, water area, etc.) Intensification: density growth (% change) in given period Based on Census data , 2006

4 Gross density of Territorial Authorities 1. North Shore City 1584 ps/km2 2. Hamilton City 1310 ps/km2 Almost half Territorial Authorities have density below 10 persons per square kilometre Lowest: Dunedin City 35 ps/km2

5 Intensification at TA level, Tauranga City 33 ps/km2 2. Selwyn District 35 ps/km2 1. Queenstown-lakes District, 60 ps/km2 One-third of Territorial Authorities became more dense between 1996 to Invercargill city -5 ps/km2

6 Comparison with Australian cities: gross density of large metropolitan regions Auckland Region: 80 persons/km 2, 1/5 of the density of Melbourne Region Sydney 343 Melbourne 408 Wellington Region: persons/km 2, 1/12 of the density of Sydney Region Gross density 2006 persons/km Ackld Region 80 Wgtn Region 28 0

7 Comparison with Australian cities: intensification of large metropolitan regions Auckland Region: 21.9% 1.6 times the intensification of Melbourne region and 2 times that of Sydney region. Wellington Region: 8.4% less than the intensification of Sydney region Intensification ( ) Ackld Region 21.9 Wgtn Region 8.4 Sydney 10.8 Melbourne

8 Comparison with Australian cities: central cities of large metropolitan region Auckland City: 605 persons/km 2, 1/3 of the density of Melbourne City City of Sydney, 7045 Wellington City: 619, 1/11 of the density of Sydney City Gross density 2006 persons/km City of Melbourne, Ackld City, 605 Wgtn City, 619 0

9 Comparison with Australian cities: Gross density of state capital cities in Australia vs. main cities of regional councils in New Zealand Average density (capital cities of states or region council ) 679 (New Zealand cities) vs 433 (Australian cities) Gross density 2006 persons/km Waitakere City North Shore City Manukau City Christchurch City Tauranga City Dunedin City Hamilton City Brisbane Adelaide Perth Hobart Darwin Canberra Gold Coast North Short City 1.7 times the density of Darwin city, the densest sate capital city in Australia

10 Comparison with Australian cities: intensification of state capital cities in Australia vs. main cities of regional councils in New Zealand Changes in gross density ( ) (%) Waitakere City Average intensification (capital cities of states or region council ) 19 (New Zealand cities) vs 13 (Australian cities) North Shore City 29.4 Manukau City Christchurch City 10.1 Tauranga City Dunedin City 17.7 Hamilton City Brisbane 21.5 Adelaide Perth Hobart 4.9 Darwin 16.3 Canberra 8.4 Gold Coast 16.4 Main cities of New Zealand had a higher average intensification than that of sate capital cities in Australia.

11 Summary findings Auckland and Wellington regions had lower densities than Melbourne and Sydney regions Auckland and Wellington regions became denser Auckland Region had higher speed of intensification than Melbourne and Sydney metropolitan regions. Main cities at Territorial Authority level in New Zealand had a higher average density than their counterparts in Australia. In NZ clear potential to increase densities in the two main metropolitan regions.

12 Wellington Region gross and net density Difference between Gross density and net density The large difference between gross density and net density reflects local hilly topographic condition is one main factor influencing the density in Wellington Region. Policy-making should think about this. Wellington City Porirua Upper Hutt City Lower Hutt City Gross density Net density N. 3 times G. N. 11 times G.

13 Wellington Region net density 3D visualization How net density shapes out urban from? Spatial distribution of density across Wellington region Click right map for movie

14 Discussion How are New Zealand Cities sprawling? Where and to what extent can we enhance intensification? Are there New Zealand models for sustainable urban development in a hilly region? What sorts of new data and methodology can be used to measure urban form better?

15 Next step research Links between density and transport energy consumption in New Zealand Percent of private vehicle for journey to work (100%) y = x R 2 = Net density (Wellington Region) persons per km2 10 people more per hectare reduces 3.2 percent of private vehicle in commuting Policy implications: housing development, transport, energy saving, and environmental management