Table 3 Standard deviation ellipses parameters of land subsidence in Zhengzhou city from 2018 to 2022.
Year | Major axis (km) | Minor axis (km) | X-axis coordinate (E/°) | Y-axis coordinate (N/°) | Rotation angle θ (°) |
|---|---|---|---|---|---|
2018 | 73.6828 | 34.8301 | 113.5543 | 34.6709 | 77.9888 |
2019 | 62.2765 | 33.3061 | 113.6069 | 34.6922 | 83.5199 |
2020 | 54.6394 | 32.5039 | 113.6343 | 34.7019 | 80.3213 |
2021 | 59.9729 | 32.2137 | 113.6163 | 34.6979 | 83.9609 |
2022 | 58.5903 | 33.3739 | 113.6229 | 34.6947 | 87.0659 |
