Julia Isabella Cannata Pechs (Spain) 1; Joan Albert López Bustins (Spain) 1; Ana Romero Càlix (Spain) 2; Ernest Ruiz Almar (Spain) 1,2; Javier Martín Vide (Spain) 1
1 - Universitat de Barcelona; 2 - Àrea Metropolitana de Barcelona (AMB)
The main objective of this project is to assess vulnerability to extreme heat in the metropolitan area of Barcelona for the 4.5 RCP scenario 2011-2040. Significantly and quantitatively, results can help prioritize areas where it is especially necessary to allocate resources to reduce the morbidity and mortality of extreme heat.
Vulnerability is calculated using a simplified and justified methodology, which aggregates exposure to extreme heat and the synergistic effects of sensitivity and adaptive capacity. The exposure variables used for this project are hot days (Tmax >30ºC), torrid days (Tmax >35ºC), tropical nights (Tmin >20ºC), and torrid nights (Tmin >25ºC) for the RCP 4.5 2011-2040 projection period. The sensitivity variables are population ≥65, women or men ≥65 living alone, inactive population, unemployed, population ≥25 years without studies, buildings ≥4 floors without an elevator, foreign born population, and rental housing. The adaptive capacity variable used is mean NDVI.
Sensitivity and adaptive capacity variables are aggregated with a Principal Component Analysis (PCA), and the resulting PCA scores are weighted and summed by their respective variance explained, and the result was normalized by z-scores. Vulnerability scores are then calculated by summing z-scores of exposure variables to the weighted normalized PCA score. Extreme heat vulnerability scores are mapped with a Geographic Information System (GIS).
Highly vulnerable zones are dispersed throughout the metropolitan area and change depending on the synergistic aggregation of which extreme heat scenario is used, the sensitivity of the population, and the adaptive capacity of the area in question. In general, the results show more vulnerability in the northeastern part of the metropolitan territory for hot and torrid days, and the southeastern part for tropical and torrid nights.
This work provides the first quantified extreme heat vulnerability assessment for the metropolitan area of Barcelona. It contributes a data-backed tool to locate and improve resource allocation and implement sustainable solutions that help prevent the increasing adverse effects of climate change. The methodology, recommendations, and guide provided in this project can also support municipalities to develop future assessments and implementation efforts with updated data and resources.