Monitoring Land Subsidence in North-central Henan Plain using the SBAS-InSAR Method with Sentinel-1 Imagery Data

As impacted by long-term underground resource exploitation and urban shallow space construction and expansion, land subsidence has turned out to be a major ground geological disaster in the central-northern Henan Plain. For the construction of the Central Plains urban agglomeration, it is required to efficiently and comprehensively grasp the information of land subsidence in the North-central Henan Plain, as well as effectively prevent and control the rapid development of subsidence. In the present study, the Land subsidence in North-central Henan Plain was initially monitored and analyzed by employing the SBAS-InSAR technology with 40 scenes of C-band Sentinel-1 data (March 2017-August 2018). As revealed from the results, the central-northern North Henan Plain consists of 6 main subsidence areas, exhibiting a maximum subsidence rate of -116 mm/a, as primarily located in the southwestern region of Baiquan Town, Hui County, Xinxiang City. To verify the results achieved by the InSAR monitoring, a GPS monitoring network and a leveling route were deployed in the study area to acquire the data of the InSAR monitoring time period. The InSAR monitoring data and GPS monitoring data were used to analyze the Beijing–Guangzhou high-speed railway, the Anyang–Xinxiang line and the South-to-North Water Transfer Project. The project and the ground subsidence along the Wari Railway are analyzed through the single-point comparison with GPS and leveling data. As indicated by the results, the InSAR monitoring results are highly consistent with the GPS and leveling data in the subsidence trend, whereas some differences exist in the values. As revealed from the calculated results, the root mean square error (RMSE) between the InSAR monitoring results and the GPS monitoring results was ± 10.96 mm/a, and the RMSE between the InSAR measurement result and the level measurement was ± 11.23 mm/a. The research results can scientifically underpin interprovincial joint prevention and control of land subsidence in the northern Henan Plain, as well as basically support sustainable economic and social development.