Table 13. Path analysis between meteorological variables and ET0 at 10 stations.
| Meteorological Variables | Correlation Coefficient | Direct Effect | Indirect Effect | Contribution to R2 | |||||
|---|---|---|---|---|---|---|---|---|---|
| Tmax | Tmin | RH | U2 | RS | Sum | ||||
| Harbin | |||||||||
| Tmax | 0.860 | 0.544 | - | 0.976 | -0.318 | -0.085 | 0.670 | 0.316 | 0.142 |
| Tmin | 0.787 | 0.003 | 0.976 | - | -0.216 | -0.097 | 0.567 | 0.784 | 0.000 |
| RH | -0.614 | -0.184 | -0.318 | -0.318 | - | -0.125 | -0.628 | -0.430 | 0.026 |
| U2 | 0.034 | 0.087 | -0.085 | -0.097 | -0.125 | - | -0.077 | -0.053 | 0.007 |
| RS | 0.865 | 0.390 | 0.670 | 0.567 | -0.628 | -0.077 | - | 0.475 | 0.749 |
| Shenyang | |||||||||
| Tmax | 0.829 | 0.565 | - | 0.968 | -0.016 | -0.039 | 0.598 | 0.264 | 0.164 |
| Tmin | 0.726 | 0.050 | 0.968 | - | 0.130 | -0.056 | 0.461 | 0.675 | 0.000 |
| RH | -0.442 | -0.236 | -0.016 | 0.130 | - | -0.087 | -0.527 | -0.205 | 0.038 |
| U2 | 0.117 | 0.136 | -0.039 | -0.056 | -0.087 | - | -0.040 | -0.019 | 0.018 |
| RS | 0.843 | 0.362 | 0.598 | 0.461 | -0.527 | -0.040 | - | 0.480 | 0.710 |
| Yan’an | |||||||||
| Tmax | 0.822 | 0.310 | - | 0.943 | -0.156 | -0.138 | 0.597 | 0.512 | 0.142 |
| Tmin | 0.673 | 0.256 | 0.943 | - | 0.068 | -0.148 | 0.388 | 0.417 | 0.004 |
| RH | -0.581 | -0.252 | -0.156 | 0.068 | - | -0.208 | -0.642 | -0.330 | 0.033 |
| U2 | 0.124 | 0.140 | -0.138 | -0.148 | -0.208 | - | 0.030 | -0.015 | 0.020 |
| RS | 0.870 | 0.420 | 0.597 | 0.388 | -0.642 | 0.030 | - | 0.450 | 0.757 |
| Jinan | |||||||||
| Tmax | 0.799 | 0.396 | - | 0.946 | -0.051 | -0.060 | 0.600 | 0.403 | 0.127 |
| Tmin | 0.643 | 0.190 | 0.946 | - | 0.176 | -0.124 | 0.417 | 0.453 | 0.002 |
| RH | -0.513 | -0.290 | -0.051 | 0.176 | - | -0.223 | -0.532 | -0.223 | 0.052 |
| U2 | 0.240 | 0.187 | -0.060 | -0.124 | -0.223 | - | 0.098 | 0.053 | 0.032 |
| RS | 0.856 | 0.366 | 0.600 | 0.417 | -0.532 | 0.098 | - | 0.490 | 0.732 |
| Nanjing | |||||||||
| Tmax | 0.765 | 0.294 | - | 0.936 | 0.015 | -0.137 | 0.504 | 0.471 | 0.144 |
| Tmin | 0.592 | 0.248 | 0.936 | - | 0.254 | -0.080 | 0.300 | 0.344 | 0.004 |
| RH | -0.485 | -0.299 | 0.015 | 0.254 | - | 0.135 | -0.524 | -0.186 | 0.038 |
| U2 | -0.091 | 0.133 | -0.137 | -0.080 | 0.135 | - | -0.237 | -0.224 | 0.017 |
| RS | 0.866 | 0.519 | 0.504 | 0.300 | -0.524 | -0.237 | - | 0.347 | 0.750 |
| Changsha | |||||||||
| Tmax | 0.776 | 0.012 | - | 0.930 | 0.019 | -0.176 | 0.610 | 0.764 | 0.070 |
| Tmin | 0.629 | 0.392 | 0.930 | - | 0.296 | -0.062 | 0.430 | 0.237 | 0.000 |
| RH | -0.343 | -0.227 | 0.019 | 0.296 | - | 0.239 | -0.378 | -0.117 | 0.012 |
| U2 | -0.133 | 0.133 | -0.176 | -0.062 | 0.239 | - | -0.265 | -0.266 | 0.015 |
| RS | 0.927 | 0.701 | 0.610 | 0.430 | -0.378 | -0.265 | - | 0.226 | 0.859 |
| Chengdu | |||||||||
| Tmax | 0.793 | 0.260 | - | 0.948 | -0.203 | -0.002 | 0.595 | 0.532 | 0.104 |
| Tmin | 0.639 | 0.146 | 0.948 | - | 0.029 | 0.028 | 0.426 | 0.493 | 0.001 |
| RH | -0.589 | -0.229 | -0.203 | 0.029 | - | -0.115 | -0.504 | -0.360 | 0.043 |
| U2 | 0.097 | 0.149 | -0.002 | 0.028 | -0.115 | - | -0.140 | -0.052 | 0.022 |
| RS | 0.895 | 0.583 | 0.595 | 0.426 | -0.504 | -0.140 | - | 0.312 | 0.801 |
| Kunming | |||||||||
| Tmax | 0.741 | 0.117 | - | 0.839 | -0.368 | -0.018 | 0.515 | 0.624 | 0.114 |
| Tmin | 0.374 | 0.289 | 0.839 | - | 0.102 | -0.165 | 0.114 | 0.085 | 0.008 |
| RH | -0.806 | -0.398 | -0.368 | 0.102 | - | -0.362 | -0.732 | -0.408 | 0.060 |
| U2 | 0.345 | 0.156 | -0.018 | -0.165 | -0.362 | - | 0.205 | 0.189 | 0.023 |
| RS | 0.878 | 0.462 | 0.515 | 0.114 | -0.732 | 0.205 | - | 0.416 | 0.771 |
| Nanning | |||||||||
| Tmax | 0.643 | 0.222 | - | 0.878 | 0.265 | -0.306 | 0.587 | 0.421 | 0.042 |
| Tmin | 0.402 | 0.256 | 0.878 | - | 0.579 | -0.263 | 0.409 | 0.146 | 0.006 |
| RH | -0.367 | -0.443 | 0.265 | 0.579 | - | -0.220 | -0.131 | 0.075 | 0.088 |
| U2 | -0.045 | 0.213 | -0.306 | -0.263 | -0.220 | - | -0.342 | -0.258 | 0.071 |
| RS | 0.865 | 0.645 | 0.587 | 0.409 | -0.131 | -0.342 | - | 0.220 | 0.748 |
| Guangzhou | |||||||||
| Tmax | 0.527 | 0.104 | - | 0.874 | 0.383 | -0.418 | 0.502 | 0.423 | 0.001 |
| Tmin | 0.270 | 0.348 | 0.874 | - | 0.694 | -0.293 | 0.285 | -0.078 | 0.069 |
| RH | -0.349 | -0.476 | 0.383 | 0.694 | - | -0.127 | -0.178 | 0.127 | 0.036 |
| U2 | -0.209 | 0.173 | -0.418 | -0.293 | -0.127 | - | -0.400 | -0.382 | 0.021 |
| RS | 0.909 | 0.741 | 0.502 | 0.285 | -0.178 | -0.400 | - | 0.168 | 0.826 |