A synthetic view of urban A synthetic view of urban development: development:

Hot topics & Research methodsHot topics & Research methods

美国城市空间发展管理：美国城市空间发展管理：热门问题与研究方法热门问题与研究方法

宋彦宋彦美国北卡罗来纳大学城市规划系 教授美国北卡罗来纳大学城市规划系 教授

北卡罗来纳大学中国城市研究中心 主任北卡罗来纳大学中国城市研究中心 主任Email: ys@email.unc.eduEmail: ys@email.unc.edu

对城市空间管理的需求对城市空间管理的需求◦城市热门问题城市热门问题◦生态城市、绿色城市、健康城市、城市减排等等

◦如何实现这些概念？对城市空间的管理形态、量、区位、转换

城市空间管理的范畴城市空间管理的范畴

Market forces市场因素

•Taxation•Land use regulation•Infrastructure•各种公共政策

Outcome Evaluation城市空间管理是否达到目标

Urban Development城市空间

Observation & Evaluation了解城市空间 (1)

(2)

(3)

(4)

Part I: Measurements Part I: Measurements 城市形态、开发模式识别城市形态、开发模式识别

Identification of development pattern

要求：◦Policy-relevant 政策相关性◦Trend-revealing 提示趋势◦Function 提示功能 Residents & Jobs 人口就业 Investments 资本投入

6

房屋开发房屋开发

7

8

Internal Street Connectivity by Age of Internal Street Connectivity by Age of

NeighborhoodNeighborhood

Median Year Built

2000199019801970196019501940

Inte

rnal

Con

nect

ivity

1.1

1.0

.9

.8

.7

.6

.5

Median Year Built

2000199019801970196019501940

Inte

rnal

Con

nect

ivity

1.1

1.0

.9

.8

.7

.6

.5

9

SFR Lot Size by Age of NeighborhoodSFR Lot Size by Age of Neighborhood

Median Year Built

2000199019801970196019501940

Med

ian

SF

R L

ot S

ize

(SQ

FT

)20000

10000

0

Median Year Built

2000199019801970196019501940

Med

ian

SF

R L

ot S

ize

(SQ

FT

)20000

10000

0

10

11

Ratio of SFR Units within ¼-Mile Network Ratio of SFR Units within ¼-Mile Network Distance of Commercial Use by Age of Distance of Commercial Use by Age of

NeighborhoodNeighborhood

Median Year Built

2000199019801970196019501940

Rat

io o

f S

FR

with

in 1

/4-m

ile o

f C

omm

erci

al U

ses 1.1

.9

.7

.5

.3

.1

-.1

Median Year Built

2000199019801970196019501940

Rat

io o

f S

FR

with

in 1

/4-m

ile o

f C

omm

erci

al U

ses 1.1

.9

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-.1

YEAR ESTABLISHED

1987 1990 1992 1995 2000 2005

Jefferson County (AL) 138 176 146 234 182 401

Cook County (IL) 329 374 367 394 278 814

Hennepin County (MN) 951 1,139 1,100 1,274 863 3,022

Alameda County (CA) 221 262 244 279 232 396

ResidentResidentialial

FirmsFirms

Part II: Causes & Part II: Causes & ManagementManagement成因 与 管理控制成因 与 管理控制Identification of development pattern

Causes & Management◦Market? 市场◦Plan / Regulations? 规划、政策？◦Taxation? 税收◦Other policies?

例子：例子：Market and Urban ExpansionMarket and Urban Expansion市场与城市扩张市场与城市扩张——土地量土地量

U.S. cities

Chinese cities

Market and Urban Market and Urban ExpansionExpansionChinese citiesU.S. cities

Events

N = 1042

Non-events

N = 5061

例子：开发区位的影响因素例子：开发区位的影响因素

1 Based on local subdivision ordinance distinction between minor and major subdivisions.

SURVIVAL ANALYSISSURVIVAL ANALYSIS

jmtjmtjrtjrt CWCW

jmtjmtjrtjrt VVPr

jT|jTPrth iiij

jTPrtS iij

Time Time period indicator Time-Variant Unclear Main effect of time

Land Market Considerations Estimated land value Time-Invariant Positive effect Hedonic regression

Parcel aggregation indicator Time-Variant Positive effect Parcel change analysis

Demographics and Neighborhood Character Percent college graduates in block group Time-Invariant Positive effect Census 2000

Number of demolitions within quarter mile Time-Invariant Positive effect Local sources

Land use mix (entropy measure) Time-Invariant Negative effect Derived from spatial dataset

Accessibility Logged distance to I-485 (finished by 2001) Time-Invariant Positive effect Derived from spatial dataset

Distance to I-485 (when complete) Time-Invariant Positive effect Derived from spatial dataset

Logged distance to nearest downtown2 Time-Invariant Unclear Derived from spatial dataset

Policy Factors Infrastructure availability proxy Time-Invariant Positive effect Ratio of street length to parcel size

Tax rate Time-Variant Negative effect Charlotte-Mecklenburg Planning

Non-residential neighborhood Time-Invariant Negative effect Neighborhood Development Dept.

Rezoning duration (average number of days) Time-Invariant Negative effect Local sources

Moratorium in place (proportion of year) Time-Variant Negative effect Local sources

“ Priming Effect” Measure Nearby events of opposite scale (or all events) in

prior period

Time-Variant Positive Parcel change analysis

Independent Variables and Hypothesized Effect: Hazard Models

Regulations and Urban Regulations and Urban Development Development 法规与开发法规与开发Land use tools / Incentives 土

地利用管理◦Developers are responsive 开发

商◦Businesses are responsive 企业

24

25

26

27

Adequate Public Facilities Adequate Public Facilities OrdinanceOrdinanceAdequate Public Facilities Urban Growth Boundary

28

29

30

Impact FeesImpact Fees

Impact Fees: monetary charges imposed on new development to recoup or offset a proportionate share of public capital costs required to accommodate such development with necessary public facilities. (Nicholas and Nelson, 1988)

Cannot legally be used for operation, maintenance, repair, alteration or replacement of capital facilities or just added to general revenue

31

TIFTIF• Tax-Increment Financing (TIF)

creates a redevelopment district, in which infrastructure improvements and/or project development are financed based upon the anticipated future increase in property values (the ‘increment’) and therefore, property taxes, that will result from the improvements.

32

Inclusionary zoningInclusionary zoning

Inclusionary zoning/housing encourages or requires developers of certain market rate residential developments to include within their developments or to construct offsite residential units made affordable to low and moderate income households.

)()( iNDtiNDtiDtiDt vvprobdevelopP

Regulations and Urban Regulations and Urban Development Development 法规与开发法规与开发◦Complications - backfire Uneven stringency may cause

development to be inefficiently dispersed in the region

Market has feedbacks

),,,,( iiiiiii RRIRXCPQQ

Tax and Urban Tax and Urban DevelopmentDevelopment税收与城市发展税收与城市发展Property tax 不动产税的两种作用第一步：税与城市土地集约使用第二步：税在空间上的分布

Tax RatesTax Rates

VariablesVariables

The correlation between urban scale and the population (or employment) density gradient is −0.33 (or −0.31): 大城市更分散

The correlation between two density gradients is 0.97.

VariablesVariables

ResultsResults

ImplicationsImplications

A lower tax rate in suburbs induces more outward developments and thus, a more expansive and decentralized urban area 郊区的低税率诱发分散性开发

Urban decentralization / urban sprawl has multiple causes and solutions 诱因与解决方法 – 分享税收？

Part III: Consequences Part III: Consequences 城市空间管理是否达到目标城市空间管理是否达到目标Housing market 房屋市场Travel, emissions and air quality 交通出行与空气质量

Health implications 公众健康Ecological and energy impacts 生态与能源

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房屋市场房屋市场

Travel, emissions and air Travel, emissions and air qualityquality

Travel, emissions and air Travel, emissions and air qualityquality

45

土地开发模式与交通压力土地开发模式与交通压力基于心理学的调适基于心理学的调适 ---- 中介作用中介作用

Travel, emissions and air Travel, emissions and air quality – Health implicationsquality – Health implications

Next steps: Self Selection◦Research Methods: Natural

experiments◦下一步热门研究：应对自我选择问题

Advanced Modeling Systems:Advanced Modeling Systems:城市模拟模型城市模拟模型Linking things together…Linking things together…

•Spatial development 城市发展模式•Transportation 交通•Emissions 排放•Air quality 空气质量•Hydrological impacts 水质量

MODELING APPROACHMODELING APPROACH

Identify future scenarios

Translate scenarios into land market & transportation system changes

Develop multimodal travel models

Estimate emissions from on-road mobile sources & rail transit vehicles

Run air quality model

Exogenous FactorsPopulation ageingIPCC’s scenariosVehicle fleet mixVehicle technology

Run land use/transport forecasting model

Develop firm and residential location models

Study area –Charlotte Study area –Charlotte 例子例子 Rapid population

increase

◦ 22 % from 1990 to 2000 Even faster land

consumption

1950: 6.98 person/acre 2000: 3.60 person/acre

Economic flows generate Economic flows generate transportation flowstransportation flows

Zone 258 demands labor

Zone 256 supplies labor

建立未来城市发展模式建立未来城市发展模式Baseline and smart growth

Source: Metrolina COG

Smart growth scenarioSG scenario

Source: Hadden

Link-based emissions Link-based emissions model – model – 排放模型排放模型Vehicle fuel and technologyFacility typeAmbient conditionsVehicle mean speed for linkVehicle class and age Vehicle fleet distributionEmission control standards and

programsSource: Frey et al 2008

Example of link-based tailpipe emission Example of link-based tailpipe emission factors: Arterials, CY 2005factors: Arterials, CY 2005

0.0

1.0

2.0

3.0

4.0

10-20 20-30 30-40 40-50 50-60

LDGV E85 CNG LDDV HEV

0

1

2

3

4

10-20 20-30 30-40 40-50 50-60

Speed (km/h)

CO

2(g/

s)

0

40

80

120

10-20 20-30 30-40 40-50 50-60

Speed (km/h)

CO

(m

g/s)

0

2

4

6

8

10

10-20 20-30 30-40 40-50 50-60

Speed (km/h)

NO

x (m

g/s

)

0

1

2

3

4

10-20 20-30 30-40 40-50 50-60

Speed (km/h)

HC

(m

g/s)

Source: Frey et al 2008

Regional emissions during Regional emissions during weekday morning peak hourweekday morning peak hour

Scenario HC CO NOx CO2

Present: Baseline 0.854 34.50 4.63 1376

Present: Alternative 0.788 29.75 4.48 1326

Future, No Growth: Baseline 0.153 9.69 0.39 1200

Future, No Growth: Alternative 0.148 8.36 0.37 1166

Future, Growth: Baseline 0.244 14.49 0.60 1849

Future, Growth: Alternative 0.237 12.57 0.56 1779

Total Transportation Network Emissions (tons)

Source: Frey et al 2008

城市热门问题城市热门问题◦生态城市、绿色城市、健康城市、城市减排等等

◦如何实现这些概念？对城市空间的管理形态、量、区位、转换

◦各种研究方法

* 规划的实施应包含比落实各种公共设施更多的内容。 * 将目标细化、落实到可以实施的行动：例如，纽约市关于管理、提高水质量的目标，就制定了十项政策行动计划；

* “ 绿色纽约“有 150 多项行动计划

如何应用这些研究成果？

城市空间管理的范畴城市空间管理的范畴——公共政策公共政策New directions 新方向—更跨领域

Market forces市场因素

•Taxation•Land use regulation•Infrastructure•各种公共政策

Outcome Evaluation城市空间管理是否达到目标

Urban Development城市空间

Observation & Evaluation了解城市空间 (1)

(2)

(3)

(4)

Conclusions Conclusions 结语结语Empirically, through different

methods, confirmed relevance of spatial development 城市空间管理的相关性

Comprehensiveness of urban management 城市空间管理的广泛性

Thank you very much!