Development and Validation of a Heat Resilience Index: Measuring Communities Resilience to Extreme Heat Events

The level of preparedness of communities to heat-related consequences varies. While several studies have developed heat vulnerability indices, little-to-no research efforts were directed to assess the heat resilience of communities. To that extent, this paper develops and validates a heat resilience index (HRI). First, a dataset of 44 indicators affecting heat resilience was collected and grouped into five categories: sociodemographic, land use/land cover (LULC), health facilities, meteorological, and geographic factors. Second, principal component analysis (PCA) was used to calculate the weights or importance of each indicator. Based on the calculated weights, five heat resilience subindices were developed for the five categories. Third, the overall HRI was developed as a weighted average of the five calculated subindices. Fourth, the developed HRI was scientifically validated based on real-world heat-related illnesses data. The HRI was demonstrated for the State of New Jersey, where the results showed that more than 71% of the studied census tracts have a poor resilience toward heat waves. Furthermore, the results highlighted that the following indicators affect heat resilience the most: median income, poverty, percentage of people younger than 5 years old, land area, building area, annual Normalized Difference Vegetation Index (NDVI), summer NDVI, number of hospitals, mean annual temperature, minimum temperature, maximum temperature, and urban elevation. Also, the results identified the LULC category as the most influential category on the overall heat resilience. The findings could assist in developing appropriate heat management and mitigation plans to enhance communities' ability to resist future heat waves, where the same method could be used to assess heat resilience for other states and countries worldwide through developing the associated dataset. Ultimately, this research adds to the body of knowledge by proposing a structured framework for developing a novel heat resilience index based on a comprehensive list of 44 indicators.