Time series subsidence analysis of drilling solution miningrock salt mines based on Sentinel-1 data and SBAS-InSAR technique

Abstract

Mining-induced dynamic deformations over drilling water-soluble rock salt mines may result in sever progressive damages to surface buildings and infrastructures. Long-term dynamic monitoring and real-time analysis of rock salt mines are extremely important in preventing potential geological damages. In this study, the small-baseline subset (SBAS) InSAR technique is initially used to monitor the settlement of drilling water-soluble rock salt mines. A time series analysis is carried out to obtain the time-space characteristics of land subsidence caused by drilling water-soluble mining activities. Then, the temporal and spatial evolution of the settlement funnel is revealed. Subsequently, the monitoring results are compared with both DInSAR and leveling deformation results for the reliability assessment. A temporal and spatial analysis is conducted for the surface subsidence. A typical drilling water-soluble rock salt mine in Changde, Hunan Province, China was selected as the test area. Twenty-one scenes from the Sentinel-1 image data covering the period from February 2016 to February 2017 were used to obtain the time series settlement sequence of the survey area. Experimental results indicate that the large-scale surface settlement over the mining area began to appear in September 2016 and with the characteristics of sedimentation funnel-multiplied peaks in the horizontal direction. The overall spatial distribution of the subsidence in the mining area appears as an overall sheet-like shape in the southwest part and a discrete belt-like distribution in the north-central part. These subsiding characteristics are consistent with mining activities that use drilling water-soluble technology. To evaluate the reliability of the results, the field-leveling deformation data are compared with the DInSAR deformation data. The results obtained by the SBAS technology are highly consistent with the leveling results. This study confirms the feasibility of applying SBAS-InSAR technology to the settlement monitoring of drilling water-soluble salt rock mines. The findings can provide a reference for the preliminary determination of mining cavity locations, aid in the developmental analysis of the characteristics of subsidence bowls, and help improve the recovery rate of water-soluble mining mines.