On the need to move from a single indicator to a multi-dimensional framework to measure accessibility to urban green

TL;DR

This paper argues that relying on a single indicator to measure urban green accessibility is insufficient due to complex spatial and population interactions, advocating for a multi-dimensional assessment framework.

Contribution

It introduces the need for a multi-dimensional framework to better evaluate urban green accessibility, moving beyond single metric assessments.

Findings

Single indicators may misrepresent green accessibility due to spatial-population interactions.

Analysis of over 1,000 cities shows instability in rankings based on single metrics.

A multi-dimensional approach provides more reliable and nuanced assessments.

Abstract

With the recent expansion of urban greening interventions, the definition of spatial indicators to measure the provision of urban greenery has become of pivotal importance in informing the policy-design process. By analyzing the stability of the population and area rankings induced by several indicators of green accessibility for over 1,000 cities worldwide, we investigate the extent to which the use of a single metric provides a reliable assessment of green accessibility in a city. The results suggest that, due to the complex interaction between the spatial distribution of greenspaces in an urban center and its population distribution, the use of a single indicator might lead to insufficient discrimination across areas or subgroups of the population, even when focusing on one form of green accessibility. From a policy perspective, this indicates the need to switch toward a multi-dimensional framework that is able to organically evaluate a range of indicators at once.