Page 91 - JCAU-6-2

Journal of Chinese
Architecture and Urbanism Residential urban heritage space study

3.2. Assessment indicators for residential urban In this context, pr(x ) represents the proportion of the
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heritage spaces number or area of buildings within a specific spatial unit.
Drawing on research pertaining to urban spatial (b) Spatial morphology entropy (SME):
morphology and material spatial composition (Carmelino SME considers key factors such as the area, perimeter,
& Hanazato, 2019), this paper divides the structural maximum width, and compactness of spatial units. The
paradigms of residential urban heritage spaces into two calculation is as follows:
systems: the Spatial Topology Relationship System and the
Spatial Material Structure System. n ( wa wp wm wc )
j
3
j
2
1
4
j
j
SMEXi() (IV)
(
3.2.1. Spatial Topological Relationship System j1 logw a w p w m w c )
3
j
j
2
1
j
j
4
Grounded in graph theory, space syntax simplifies the Here, n is the number of morphological features
complex urban road network by abstracting its elements within that spatial unit, aj represents the area of a specific
into nodes and edges. By utilizing metrics such as distance spatial unit, p represents the perimeter, m represents the
j
j
and degree, each node (or axial line) is quantified to maximum width, and c represents the compactness of that
j
determine its spatial significance within the broader urban spatial unit. The weights w , w , w control the influence of
1
2
3
network (Hillier, 1996). Notably, the “Integration Index” different factors in the SME.
stands out among these metrics. This index accounts for (c) Function mixing entropy (FME):
the connectivity between a node and all other nodes in the
system, along with its role in path selection. It provides FME serves as an indicator that reflects the functional
valuable insights into the key roads and primary material diversity within a space by statistically analyzing the
flow pathways within residential urban heritage spaces. distribution of different types of urban points of interest
The calculation method is as follows: (POIs) within each spatial unit. The calculation is as
follows:
Int. (i)=w D(i)+w C(i)+w H(i) (II)
1 2 3
In this formula, i represents a specific node, D(i) FMEX( i ) n ( pe )log ( pe ) (V)
j
j
represents the degree of connectivity for that node, C(i) j1
represents the choice value, and H(i) represents the depth Here, FME(X) represents the FME for a specific spatial
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value. The weights w , w and w control the influence of unit X, and n is the number of different types of urban POIs.
2
3
1
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different factors in the integration index. For each POI type j, its proportion pe within the spatial
j
The analysis results of the Integration Index are unit is calculated. This proportion is then multiplied by its
influenced by the radius of human activity within the logarithm, and the results for all POI types are summed to
space. By setting the range of human activity for daily life obtain the FME.
circles (1000 m) and long-distance movement behavior (d) Heritage space entropy (HE):
(5000 m), the Integration Index is transformed into two
dimensions: Local Centrality (Int.V R1000 ) and Global HE classifies each spatial unit based on specific
Centrality (Int.V R5000 ). By employing this approach, we can attributes of the heritage space (such as historical
accurately locate and define the topological relationships significance and cultural value) and calculates the entropy
within the heritage space, as well as the spatial topology of value to assess the diversity and complexity of the heritage
the overall area. space. This process aids in identifying important historical
and cultural areas. The calculation is as follows:
3.2.2. Spatial Material Structure System
When conducting urban space analysis within the HE X( i ) n j1 ( h logh) ( ) (VI)
j
j
framework of the spatial material structure system, the
following are the basic calculation formulas and brief Here, HE(x ) represents the HE of a specific spatial
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definitions for these indicators: unit X, and n is the number of different heritage attributes.
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(a) Architectural density entropy (ADE): h denotes the proportion of each heritage attribute j within
j
the spatial unit.
ADE is used to measure the concentration level of
buildings within different spatial units, thereby reflecting (e) Residential entropy (RE):
the density of buildings. The calculation is as follows: RE calculates the entropy based on the distribution
ADEX( i ) pr x()log prx( ) (III) of different residential uses within a spatial unit, thereby
reflecting the diversity of residential areas and changes
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Volume 6 Issue 2 (2024) 5 https://doi.org/10.36922/jcau.1732