Combination of InSAR Techniques for Modeling The Decay Time of Surface Deformation Rates in Mining-Impacted Areas

The aim of this paper is to employ satellite interferometry to analyze the spatial variability of mining-induced surface subsidence decay time after the end of underground mineral extraction. The tests were performed in the area of one of the Legnica-Glogow Copper Belt mines, in which copper ore is extracted at significant depths. The research was based on a modified methodology for determining the time coefficient c of the Knothe function based on SAR data, adapted to the Small Baseline Subset time series method. The results, validated against classic geodetic measurements, indicate that surface deformations can become visible as late as approximately eight years after the end of mining operations, with the surface deformation decay time being inversely proportional to the value of surface subsidence measured during the operations. Statistical tests showed that the distribution of the time coefficient c of the Knothe function corresponds to the Gaussian distribution, and that it can therefore be applied in predicting the decay time of mining deformations. The results may have significant implications for land-use planning in post-mining areas and may enable a precise determination of the deformation decay time across the entire subsidence trough. The research results indicate that surface change dynamics can be analyzed more precisely with the use of InSAR methods combined with the Knothe time function than with the use of traditional geodetic methods.