A Raster-Based Subdividing Indicator to Map Urban Heat Vulnerability: A Case Study in Sydney, Australia.

Wei Zhang,Phil Mcmanus,Elizabeth Duncan

doi:10.3390/ijerph15112516

Abstract

Assessing and mapping urban heat vulnerability has developed significantly over the past decade. Many studies have mapped urban heat vulnerability with a census unit-based general indicator (CGI). However, this kind of indicator has many problems, such as inaccurate assessment results and lacking comparability among different studies. This paper seeks to address this research gap and proposes a raster-based subdividing indicator to map urban heat vulnerability. We created a raster-based subdividing indicator (RSI) to map urban heat vulnerability from 3 aspects: exposure, sensitivity and adaptive capacity. We applied and compared it with a raster-based general indicator (RGI) and a census unit-based general indicator (CGI) in Sydney, Australia. Spatial statistics and analysis were used to investigate the performance among those three indicators. The results indicate that: (1) compared with the RSI framework, 67.54% of very high heat vulnerability pixels were ignored in the RGI framework; and up to 83.63% of very high heat vulnerability pixels were ignored in the CGI framework; (2) Compared with the previous CGI framework, a RSI framework has many advantages. These include more accurate results, more flexible model structure, and higher comparability among different studies. This study recommends using a RSI framework to map urban heat vulnerability in the future.

Highlights

Heat waves are becoming a significant public health concern
The very high heat vulnerability indicators (HVI) area has been of primary concern in previous research [2,58], so we explored the spatial stability of RSHVMs and raster-based general heat vulnerability map (RGHVM) in very high HVI areas
This study provides a new raster-based subdividing indicator (RSI) framework to assess and map urban heat vulnerability

Summary

Introduction

Heat waves are becoming a significant public health concern. In Australia, heat waves have caused more deaths than any other natural hazard, except disease, over the past 200 years [6]. Heat waves are of particular concern in large urban areas, where there are population concentrations and where the urban heat island (UHI) effect exacerbates temperatures [8,9]. The urban heat is superimposed on the background mesoscale climate, which exacerbates heat exposure and increases the risk of mortality and morbidity in cities [10,11]. Duration, and intensity of heat waves are predicted to increase [12], research is increasingly focused on the impacts of heat waves on public health in urban areas

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Discussion

Conclusion