Spatial modelling of the relationship between the urban form and population data

Anna Brazdova, Martin Fleischmann, Lisa Winkler

Charles University

About me

1st year Ph.D student at the department of Social geography and Regional Development

Faculty of Science at Charles University in Prague

Interplay between population and urban form

Understand built-up patterns of housing types and the ability of different population groups to inhabit them.

Spatial modelling of the relationship between the urban form and population data

Who lives in different types of the urban form?

Is there a specific relationship between a group of people and an urban form type?

Does it differ across the country?

How to asses this relationship?

Urban form types as the target variable

Census characterstics as the predictors

Methods

Dimensinality reduction of census data

Geographicaly weighted prediction models

Case Study of Czechia

Morphometric classification

Quantitative identification of urban form types.

Based on similar morphological characteristics shared by street segments and building footprints.

Focuses on geometry and spatial configuration within the urban fabric.

Level 3 of the classification - 6 main types in Czechia

Central Urban Developments

Dense Urban Developments

Street-aligned Developments

Sparse Rural Developments

Sparse Road Network Developments

Large Scale Developments

Scale

Census variables

Age structure

Education

Economic activity

Employment type

Marital status

Households

Religion

Nationality

Residence

Property ownership

Spatial relationship

Who lives in different types of the urban form?

Is there a specific relationship between a group of people and an urban form type?

Does it differ across the country?

How to asses this relationship?

Census processing

800+ variables

Variable selection - no leakage, no nested variables, repetition etc.

Data normalization and standardization

Dimensionality reduction

Dimesionality reduction

Principal Component Analysis

Factor Analysis

Uniform Manifold Approximation and Projection

Geographically weighted modelling

Global models assume the same relationship between predictors and target classes across the entire dataset

They do not account for the geographic variation in the relationship

Geographically weighted models capture this by applying local models rather than a single global model.

Geographically weighted classification

Similar in concept to Geographically Weighted Regression (GWR).

Categorical or class-based outcomes.

Separate classifier for each location using data weighted by geographic proximity.

Weighting

Controlled by a distance-decay parameter.

Nearby observations are given more weight than distant ones.

Illustration of bandwidth and its relation to weight, Fotheringham et al. (2002, 44–45)

Bandwidth

Controls the spatial scale over which a process varies.

Conceptual diagram explaining fixed (left) and adaptive weighting (right) schemes. Sachdeva, M., & Fotheringham, A. S. (2020)

Modelling

Outputs from dimensionality reduction → Geographically weighted models

Logistic Regression & Random Forest Classification

Binary Classification

The distribution of urban form classes is uneven across space.

Some urban forms do not appear in certain locations at all.

Each model can be tuned to local prevalence and have custom thresholds, weights, bandwidth…

Results

Principal Components

  1. Economic activity of the population

  2. Property ownership, family household with children

  3. Czech nationality and permanent residency

Conclusion

Relationship does differ geographically.

Specific relationship between population characteristics and urban form types.

Dimensionality reduction or cluster analysis?

Work still in progress, would appreciate some feedback!

Thank you

kryndlea@natur.cuni.cz

www.linkedin.com/in/kryndlea