Regional Geodetic Reference Frames for Geological Hazards and Structural Deformation Monitoring in North and South China

Abstract:

We have established two stable regional geodetic reference frames for geological hazards and structural deformation monitoring in North and South China, designated as NChina20 and SChina20, using approximately 10-year observations (2010-2019) from 40 Global Navigation Satellite System (GNSS) stations in each region. The regional reference frames are aligned in origin, scale, and orientation with the International GNSS Service (IGS) Reference Frame 2014 (IGS14). The primary products from this study are two sets of 7-parameters for transforming the Earth-Centered-Earth-Fixed (ECEF) XYZ coordinate time series from IGS14 to NChina20 and SChina20 and two mathematical models for predicting seasonal ground deformation (vertical) within North China and South China. The frame stability of NChina20 is 0.5 mm/year in the horizontal direction and 0.6 mm/year in the vertical direction. The frame stability of SChina20 is 0.4 mm/year in both horizontal and vertical directions. We have also established a local-scale reference frame for the Hong Kong, Zhuhai, and Macau (HZM) area, designated as HZM20. The local-scale reference frame retains even higher frame stability, 0.3 mm/year in all three directions. Applications of NChina20, SChina20, and HZM20 in delineating urban subsidence and landslide are demonstrated in this article. These regional reference frames will be updated every few years to mitigate the degradation of the frame stability over time and to synchronize with future updates of the IGS reference.