Studying sinkholes of the earth’s surface involving radar satellite interferometry in terms of Zhezkazgan field, Kazakhstan

Abstract

Purpose is to assess the potential of radar satellite interferometry (SAR interferometry) to analyze and forecast earth’s surface displacements. Methods. The study involves the analysis of previous instrumental observations, such as high-precision levelling and seismic monitoring. The observations using global navigation satellite systems (GNSS) were carried out; satellite images were processed applying a method of sequential interferometry of persistent radar signal scatters (PS). Findings. The research results have proved similarity between the data obtained with the help of ground instrumental methods and the data received using satellite interferometry. Two types of the earth’s surface sinkholes were identified: sinkholes with smooth subsidence and hidden deformations that are not accompanied by the preliminary deformational or seismic signs. Smooth subsidence is controlled and predicted successfully with the help of the SAR interferometry methods. An algorithm has been represented to predict linear displacement trends at different time intervals involving a finite element method. Originality is in a complex approach of the research performance covering the following: comparative analysis of different monitoring methods, studying different sinkhole types, identifying limitations of the available methods, and proposing new approaches for more accurate and objective analysis of the earth’s surface deformation within the field. Practical implications. The research results are of practical value for rock mechanic specialists and mining operators. They can use the data to monitor and control earth’s surface caving as well as provide staff safety and preserve ground infrastructure where it is possible.