Table 1 Mann-Kendall statistics of annual total illuminance in typical Chinese climate regions
From: The trend of natural illuminance levels in 14 Chinese cities in the past 50 years
Cities | Z value | Average annual total value (108 lx) | Trend | Q′ | Regression equation | R2value |
|---|---|---|---|---|---|---|
Beijing | -5.571 | 90.9 | Decrease | -0.37 | y = -0.37x + 826.38 | 0.663 |
Changchun | -1.477 | 86.13 | Decrease | -0.06 | y = 0.06x + 206.2 | 0.045 |
Erenhot | -2.18 | 106.2 | Decrease | -0.098 | y = -0.098x + 301.04 | 0.02 |
Guangzhou | -2.71 | 80.3 | Decrease | -0.17 | y = -0.174x + 426.14 | 0.138 |
Heihe | 0.078 | 78.4 | Increase | 0.0036 | y = -0.123x + 71.3 | 0 |
Urumchi | -3.04 | 91.1 | Decrease | -0.123 | y = -0.123x + 335.52 | 0.21 |
Xi'an | -3.7 | 83.3 | Decrease | -0.31 | y = -0.31x + 704.6 | 0.276 |
Xining | -4.215 | 105.6 | Decrease | -0.28 | y = -0.28x + 662.4 | 0.238 |
Yushu | -1.3 | 113.9 | Decrease | -0.19 | y = -0.19x + 500.9 | 0.1 |
Fuzhou | -0.044 | 83.5 | Decrease | -0.0026 | y = 0.003x + 88.7 | 0 |
Kunming | 2.357 | 102.8 | Increase | 0.188 | y = 0.19x -270.4 | 0.11 |
Shanghai | -2.56 | 86.1 | Decrease | -0.14 | y = -0.14x + 369.8 | 0.16 |
Changsha | -3.69 | 76.9 | Decrease | -0.26 | y = -0.26x + 602.7 | 0.28 |
Chongqing | -3.96 | 63 | Decrease | -0.24 | y = -0.24x + 547.8 | 0.34 |