WANG Cheng, postgraduate, majors in geodetic inversion of crustal deformation, E-mail: 2022126014@chd.edu.cn
To address the issues of abnormal and non-smooth fitting results in sparse monitoring station areas and block margins when using the traditional least squares collocation (TLSC) algorithm for high-precision fitting of crustal motion velocity fields in large-scale regions, a K-means clustering-based least squares collocation method (KLSC) is developed by integrating the K-means clustering algorithm with the TLSC algorithm. The effectiveness of this method is validated using the GNSS-measured crustal motion velocity field on the Qinghai-Xizang plateau. The results show that: 1) Compared to the TLSC algorithm, the KLSC algorithm leverages the advantages of the K-means algorithm in unsupervised classification to first divide the study area into multiple sub-regions with similar velocities based on the inherent characteristics of the GNSS velocity field, and then applies TLSC for velocity field fitting within each sub-region, thereby avoiding the impact of local complex geological environments on the accuracy of regional velocity field fitting; 2) The KLSC algorithm selects fitting parameters based on the proximity of each grid point to the cluster centers, resolving the issue of poor fitting results in data-sparse areas; 3) By utilizing secondary nearest-neighbor fitting combined with convolution filtering, the KLSC algorithm effectively addresses the non-smooth fitting results at block margins; 4) The RMSE accuracy and correlation of the velocity fields fitted by the KLSC algorithm are superior to those of the TLSC algorithm, with improvements in RMSE accuracy of 37% to 48.2% and 52.1% to 67.2%, and increases in correlation of 24.1% to 24.7% and 4.7% to 5.2% for the eastward and northward fitted velocity fields, respectively.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |