THE THEORY OF THE NATURAL URBAN TRANSFORMATION PROCESS: The Relationship between Street Network Configuration, Density and Degree of Function Mixture of Built Environments Akkelies van Nes, [email protected], Delft University of Technology Yu Ye, [email protected], The University of Hong Kong AESOP 1. THE OUTLINE OF THE THEORY OF THE STREET FUNCTIONS NETWORK NATURAL URBAN TRANSFORMATION PROCESS The ‘urban transformation’ process -- a process when an urban area transform from a deserted to a vital and attractive place. spatial planning The natural urban processes in the transformation Urban transformation is spatially dependent on streets with high spatial last 50 years process integration values on various scales aggregating high building density STREET BUILDING BUILDING FUNCTIONS NETWORK planned DENSITY accumulated DENSITY and a high degree of land use diversity. The spatial configuration of the street network, as the foundation, influences the degree of density and functional mix. Likewise, the degree of density influences the degree of functional mix. Current Urban Planning Practice Natural Urban Transformation Processes

Applying Space Syntax to Measure Applying Spacematrix to Measure Applying MXI to Measure Degree of the Street Network Configuratiuon the Building Density Functional Mxiture 2. EMPIRICAL SUPPORT: AMENITIES I

F 80 20 RESEARCH METHODS H

BIFUNCTIONAL E 60 40

G D 40 60 Applying Space Syntax, C B A MIXED Spacematrix and Mixed-use 20 80 Index (MXI) to quantitative research A: low-rise point type B: low-rise stripe type C: low-rise block type MONOFUNCTIONAL D: mid-rise point type E: mid-rise stripe type F: mid-rise block type WORKING HOUSING G: high-rise point type H: high-rise stripe type I: high-rise block type AMENITIES the interacted relationship between the

Angular analyses Angular analyses L=7 Space Syntax analyses FSI 80 20 three essential elements of urban form: with topological radii with metric radii I High values High values 2.5 High integration values Middle values High values H High level Middle rise stripe or block types; high rise block types street network, building 2.0 G values values 60 40 High Middle 3 Middle level Low rise block or middle rise point, high rise Highpoint values: or strip types values values Middle Middle 1.5 F Multifunctional desnity and degree of Middlei integration values High values Low values Low level Low rise point and low rise stripe types Low values High values 1.0 E 40 60

Middle values Low values Middle values: functional mixture C 1 0.5 D Low integration values Low values Middle values B Bifunctional A 20 80 Low values Low values 0.0 0.00 0.15 0.25 GSI High level Mixture of three functions Low values: Middle level Bi-functional areas Monofunctional High value: E; F; I Middle value: C; D; G; H Low value: A; B WORKING HOUSING Low level Mono-functional areas

Categories of The division of values from space Combining the three Examples urban areas syntax, spacematrix and MXI measurements can provide a 1) Suburban areas L/L/L, M/L/L, L/L/M, L/M/L morphological classification of various urban types, which is able to indicate an urban area’s degree 2) Low urban areas L/M/M, M/L/M, M/M/L of socio-economic performance, in

3) In-between (low) areas H/L/L, L/H/L, L/L/H other words, various degrees of 4) In-between (middle) areas H/M/L, M/H/L, L/M/H, H/L/M, L/H/M, M/L/H ‘urbanity’. 5) In-between (high) areas H/H/L, H/L/H, L/H/H

6) Middle urban areas M/M/H, M/H/M, H/M/M, M/M/M A highly integrated area with high building density and high degree of

functional mixture should be more Combining Three 7) highly urban areas H/H/H, H/M/H, M/H/H, H/H/M Measurements for Providing a ‘urban’ than a mono-functional urban

Morphological Classification of L = Low values, M = Middle values, H = High values area with low street network integration Various Urban Types and low building densities. 2. EMPIRICAL SUPPORT: ANALYSES According to a set of socio-economic indicators, four cases’ urban transformation phases are ranked as LELYSTAD HAARLEM ALMERE follows: Haarlem scores highest AMSTERDAM (4) > Zoetermeer (3) >Almere ZOETERMEER DEN HAAG (2) > Lelystad (1).

The degrees of building density and land use mixture increase over time in a natural urban transformation process N 0 10 30 70KM while spatial integration of SPACE SYNTAX & MXI & SPACEMATRIX NETHERLANDS SPACE SYNTAX & MXI & SPACEMATRIX L M H n n street networks tends to ential ential

SururbanLow urban Middle urbHighlya urba URBAN TRANSFORMATIONLow potential PHASE 1: URBAN TRANSFORMATION PHASE 2: Middle poHighlyt pot remain stable for a longer SPACE SYNTAX & MXI & SPACEMATRIX L M H Spatial Cityn n Values Mix Density LELYSTAD ALMERE integration ential ential time period. SururbanLow urban （ ） ） Middle urbHighlya urba High 80 (7.2%)7.2% 7 ((0.6%)0.6% 36 (3.2%) Low potential The Morphologcial Results Combining Three Measurements High suburban Suburban LowMiddle Middlepotential po Highlypotential tHigh po potential t Lelystad Urban High Urban Middle 475 （(42.8%)42.8%） 172 (15.5%)15.5%） 90 (8.1%) are in Line with the Socio-economic Ranking Low 556 （(50.0%)50.0%） 932 （(83.9%)83.9%） 985 (88.7%) Dividing high and middle integrated values from the space syntax analysis High 160 (7.9%) 22 (1.1%) 96 (4.8%) Almere Middle 1007 (49.8%) 322 （(15.9%)15.9%） 292 (14.5%) by all high and middle values from all Low 853 （42.3%） 1676 (83.0%) 1632 (80.7%) three spatial measurements gives the

High 78 (7.6%) 47 （(4.5%)4.5%） 91（(8.8%)8.8%） following results: 6.8 % in Zoetermeer Middle 405 (39.2%) 312 （(30.2%)30.2%） 240 (23.3%) Low 540 (52.2%) 674 （(65.3%)65.3%） 712 （(68.9%)68.9%） Lelystad, 8.4% in Almere, 18.3% in Zoetermeer, and to High 103 (6.9%) 166 (11.1%) 231 (15.5%) Haarlem MiddleHigh 541 (36.3%) 521 (34.9%) 455 (30.5%) 36.8% in Haarlem. Low 848(56.8%) 805 （(54.0%)54.0%） 806 (54.0%)

Transformation Spatial City grids with high and middle values grids with high and middle values Match rate City process integration Mix Density from all measurements from space syntax

Phase I Lelystad Lelystad 38 555 6.8%

URBAN TRANSFORMATION PHASE 3: Almere Phase II 8.4% ZOETERMEER Almere 98 1167

18.3% Zoetermeer Phase III e n n w l h n n Zoetermeer 89 486 a a o d ig a a rb l id h rb rb u n u urb e m n u ur w e e le ly S o w n e d h L t e w d g e e t i i L M H Phase IV 36.8% b w e M H SPACE SYNURBANTAX & MXI &TRANSFORMATION SPACEMATRIX PHASE 4: Haarlem Haarlem 237 644 - t b n n n e - ential I b ential n HAARLEM Sururban - I Low urban n Middle urbHighlya urba I Low potential High suburban LowMiddle potential poHighlyt pot