Definition of characteristic subsidence parameters. A case study in the Catalan potassium basin

Abstract

Subsidence is one of the main environmental impacts of underground mining worldwide. Besides, the increasing complexity of underground mining due to greater depths and interaction with inhabited and environmentally sensitive areas can lead to challenges that may threaten the viability of mining due to phenomena such as subsidence. This research aims to increase the knowledge about surface subsidence due to underground mining, characterising the main factors that rule mining subsidence utilising an actual mine that extracts potash. The calculation methodology was based on 74 sections of the subsidence basin, using GPS measurements and the InSAR technique, with data collected over twelve nonconsecutive years from 1995 to 2021. Thus, three different active areas and one residual area were determined. Average boundary angles and their average distances of influence for the active regions have also been determined. Furthermore, using the least squares method, the subsidence basin curve was defined using a Gaussian function. The algorithm that governs the subsidence process has been successfully calculated, allowing the approximation of the deformation of any point within an area of interest. The novelty of this paper is twofold: the results obtained provide a detailed subsidence behaviour and a prediction model of the case study. Furthermore, the methodology implemented can be applied to other subsidence basins with mines in their area of influence. Hence improving the surface mining area’s safety levels and managing the environmental impacts.