Table 2. Factor loadings for extreme heat vulnerability for the four retained varimax-rotated based on data from 19 representative cities, 15 PLADs in China from 2014 to 2018.
| Item |
Principal
component 1 |
Principal
component 2 |
Principal
component 3 |
Principal
component 4 |
| * P95 is the 95th percentile of the daily maximum temperature; Bold font is the greater correlation between the evaluation index and the principal component | ||||
| Frequency of heat waves | −0.24 | 0.70 | −0.21 | 0.23 |
| Annual average temperature (℃) | −0.35 | 0.80 | 0.29 | 0.17 |
| Annual average relative humidity (%) | −0.28 | 0.76 | −0.01 | −0.29 |
| PM2.5 (µg/m3) | −0.15 | −0.11 | −0.20 | 0.90 |
| NO2 (mg/m3) | 0.08 | −0.12 | 0.18 | 0.88 |
| Daily maximum temperature≥P95* days | 0.17 | 0.49 | 0.04 | −0.02 |
| Elderly dependency ratio (%) | −0.82 | 0.02 | −0.25 | 0.31 |
| Poverty population ratio (%) | 0.13 | −0.35 | −0.47 | −0.66 |
| living alone (%) | −0.07 | 0.08 | 0.85 | −0.21 |
| Proportion of households with 5 or more persons (%) | 0.23 | 0.81 | −0.09 | 0.09 |
| Maternal mortality rate (1/100,000) | 0.89 | −0.17 | −0.28 | 0.07 |
| Perinatal mortality rate (‰) | 0.91 | −0.07 | −0.21 | 0.05 |
| Morbidity rate of infectious diseases (1/100,000) | 0.90 | 0.09 | −0.06 | −0.01 |
| Per capita GDP (CNY) | −0.21 | 0.11 | 0.83 | 0.08 |
| Per capita medical care expenditure (CNY) | 0.39 | −0.56 | 0.37 | 0.17 |
| Green coverage rate of built district (%) | −0.04 | 0.50 | 0.45 | 0.42 |
| Air conditioning quantity | −0.62 | 0.50 | 0.45 | 0.25 |
| Electricity demand (100,00 / kWh) | −0.05 | −0.04 | 0.84 | 0.26 |
| Daily water consumption (L) | 0.06 | 0.77 | 0.36 | −0.10 |
| Volume of precipitation | −0.31 | 0.78 | 0.36 | −0.20 |