Quantifying Urban Diversity: Multiple Spatial Measures of Physical, Social, and Economic Characteristics - Computational Approaches for Urban Environments - page 152

The datasets employed here are largely (and increasingly) available for major
cities worldwide. Street centerlines, cadastral data, and population aggregation data
are among the most common data layers maintained by city governments that are
employing Geographic Information Systems in their planning analyses. This bodes
well for the replication of this work, using the proposed methodology in cities across
continents.

7.4 Methodology

The method of research for this study consists of the creation of four individual
indices for each of Jacobs' four generators of diversity, as well as a single composite
index combining all of the four individual indices. The individual indices utilize
data that is rescaled to range from 0 to 1. This facilitates the computation of the
final index by giving all four parameters equal weights. Other methods, such as the
utilization of a z-score, were considered, but this tends to force the parameter values
into artificial distributions which may or may not hold true between different cities
and require differing transformations, limiting the portability of the methodology.
By utilizing rescaled values, this methodology may then be applied to different cities
across global regions.
For the first parameter, dwelling density, each of the ownership points is assigned
to a block group, and the area for each block group is calculated. Next, all points
defined by their use code as residential (see Table 7.1 ) are selected. For properties
where a single dwelling is represented by a single point (single-family homes,
condominiums, etc.), a value of “1” is assigned to that point. For properties where
multiple dwellings are represented by a single point (such as rental apartments),
a value corresponding to the total number of dwellings is assigned. These values

Tabl e 7. 1 Truncated list of
residential uses for dwelling
density

Use Code Description

003 Residential-transient

011 Residential-row-single family

012 Residential-detached-single family

::: :::

022 Residential-apartment-elevator

023 Residential flats-less than 5

024 Residential-conversions-less than 5

025 Residential-conversion-5 units

::: :::

127 Coop-vertical-mixed use

216 Condo-investment-horizontal

217 Condo-investment-vertical

316 Condo-duplex