| Id |
Subject |
Object |
Predicate |
Lexical cue |
| T106 |
0-28 |
Sentence |
denotes |
Pearson correlation analysis |
| T107 |
29-251 |
Sentence |
denotes |
The Pearson correlation coefficient was determined by constructing a heatmap for the concentration of various pollutants (pre and during pandemic confinement) among populous sites of four metropolitan cities of India, viz. |
| T108 |
252-326 |
Sentence |
denotes |
ITO, Delhi, Worli, Mumbai, Jadavpur, Kolkata, and Manali Village, Chennai. |
| T109 |
328-345 |
Sentence |
denotes |
Site 1—ITO, Delhi |
| T110 |
346-576 |
Sentence |
denotes |
At this site, the perfect positive correlation was observed between AQI and PM2.5, a strong positive correlation between AQI-PM10 and PM2.5-PM10, whereas a negative correlation was observed for ozone with AQI and other pollutants. |
| T111 |
577-750 |
Sentence |
denotes |
The correlation coefficient between AQI-PM2.5, AQI-PM10, and PM2.5-PM10 was found as 0.98, 0.82, and 0.77 respectively, showing a significantly higher positive relationship. |
| T112 |
751-934 |
Sentence |
denotes |
This indicate the changes in PM2.5 and PM10 concentrations have a great influence on AQI content; i.e., an increase in their concentration will directly elevate the air quality index. |
| T113 |
935-1169 |
Sentence |
denotes |
Besides, AQI-ozone, PM2.5-ozone, and PM10-ozone confirmed low negatively correlated variables, i.e., − 0.31, − 0.38, and − 0.18 respectively indicating the higher values of AQI, PM2.5, and PM10 will lower down the ozone concentration. |
| T114 |
1170-1312 |
Sentence |
denotes |
A feeble correlation exists between AQI-NH3 (0.46), AQI-NO2 (0.38), AQI-SO2 (0.28), and AQI-CO (0.11) showing mild effect on AQI (Fig. 5 (a)). |
| T115 |
1313-1487 |
Sentence |
denotes |
Fig. 5 Pearson’s correlation heatmap for air pollutants during the pre and COVID-19 pandemic confinement, 2020 among populous sites of four major metropolitan cities in India |
| T116 |
1489-1509 |
Sentence |
denotes |
Site 2—Worli, Mumbai |
| T117 |
1510-1668 |
Sentence |
denotes |
Product-moment correlation coefficient analysis for site 2 demonstrates the positive correlation between all of the studied pollutants as shown in Fig. 5 (b). |
| T118 |
1669-1902 |
Sentence |
denotes |
The highest correlations were confirmed between AQI-PM2.5, with a correlation of 0.97, AQI-PM10, with 0.94, and PM2.5-PM10, with 0.91 which demonstrates PM2.5 and PM10 are the most significant dominating factors in elevating the AQI. |
| T119 |
1903-2130 |
Sentence |
denotes |
A correlation value of 0.80, 0.74, 0.72, and 0.86 between AQI-NO2, AQI-NH3, AQI-SO2, and AQI-CO indicates a significant positive relationship, while moderate correlation was determined between CO and ozone concentration (0.53). |
| T120 |
2132-2156 |
Sentence |
denotes |
Site 3—Jadavpur, Kolkata |
| T121 |
2157-2363 |
Sentence |
denotes |
A significant positive correlation was observed between the prominent pollutants PM2.5, PM10, NO2, NH3, and CO with AQI, i.e., 0.96, 0.95, 0.86, 0.70, and 0.70 respectively in site 3 as shown in Fig. 5 (c). |
| T122 |
2364-2653 |
Sentence |
denotes |
This implies the studied pollutants had a great impact on air quality among monitoring station of Jadavpur, Kolkata, whereas ozone shows a negative correlation with AQI (− 0.25), and other studied pollutants i.e., PM2.5 (− 0.32), PM10 (− 0.36), NO2 (− 0.48), NH3 (− 0.50), and CO (− 0.35). |
| T123 |
2654-2797 |
Sentence |
denotes |
This indicates mean O3 concentration will significantly increase with a decrease in the mean AQI, PM2.5, PM10, NO2, NH3, and CO concentrations. |
| T124 |
2799-2829 |
Sentence |
denotes |
Site 4—Manali Village, Chennai |
| T125 |
2830-3044 |
Sentence |
denotes |
Pearson’s correlation heatmap for Manali Village, Chennai demonstrates significant positive correlations for PM2.5 (0.69) and PM10 (0.73) with AQI, while other pollutants exhibit a moderate or negative correlation. |
| T126 |
3045-3298 |
Sentence |
denotes |
The lowest values of correlation coefficient were found for the pairs AQI-NO2 (0.26), AQI-NH3 (0.04), and AQI-CO (0.33) indicating mild association between these variables; i.e., the effect of concentration of NO2, NH3, and CO on air quality is minimal. |
| T127 |
3299-3520 |
Sentence |
denotes |
However, the approximately zero correlation between AQI-SO2 (0.009) and AQI-ozone (0.01) indicates no linear relationship, but there may be some other strong non-linear relationship between the two variables (Fig. 5 (d)). |
| T128 |
3521-3622 |
Sentence |
denotes |
In other words, we can say that the simple linear function cannot describe its relationship in depth. |
