InSAR Modeling and Deformation Prediction for Salt Solution Mining Using a Novel CT-PIM Function

Xuemin Xing,Zhihui Yuan,Lifu Chen,Zefa Yang,Wei Peng,Tengfei Zhang,Xiangbin Liu

doi:10.3390/rs14040842

Abstract

Deformation prediction for a salt solution mining area is essential to mining environmental protection. The combination of Synthetic Aperture Radar Interferometry (InSAR) technique with Probability Integral Method (PIM) has proven to be powerful in predicting mining-induced subsidence. However, traditional mathematical empirical models (such as linear model or linear model combined with periodical function) are mostly used in InSAR approaches, ignoring the underground mining mechanisms, which may limit the accuracy of the retrieved deformations. Inaccurate InSAR deformations will transmit an unavoidable error to the estimated PIM parameters and the forward predicted subsidence, which may induce more significant errors. Besides, theoretical contradictory and non-consistency between InSAR deformation model and future prediction model is another limitation. This paper introduces the Coordinate-Time (CT) function into InSAR deformation modeling. A novel time-series InSAR model (namely, CT-PIM) is proposed as a substitute for traditional InSAR mathematical empirical models and directly applied for future dynamic prediction. The unknown CT-PIM parameters can be estimated directly via InSAR phase observations, which can avoid the error propagation from the InSAR-generated deformations. The new approach has been tested by both simulated and real data experiments over a salt mine in China. The root mean square error (RMSE) is determined as ±10.9 mm, with an improvement of 37.2% compared to traditional static PIM prediction method. The new approach provides a more robust tool for the forecasting of mining-induced hazards in salt solution mining areas, as well as a reference for ensuring the environment protection and safety management.

Highlights

There still exist limitations: Firstly, according to previous studies, pure empirical mathematical models are mostly utilized to generate the InSAR observations, and the underground mining subsidence mechanism is not considered in the InSAR modeling procedure
The traditional mathematical models used in the deformation monitoring is not consistent with the Probability Integral Method (PIM) used in the future deformation prediction, which is based on random medium theory
The profile analysis results based on the SBAS-InSAR derived time series subsidence are shown in Figure 19, while the CT-PIM results are shown as Figure 19

Summary

Introduction

By the end of 2018, the reserves of mirabilite deposits in China had reached up to. 117.297 billion tons [1]. For mirabilite production in the salt mining deposits, watersoluble exploitation, with comprehensively multi-propulsion through groups of drilling wells, is the primary mining mode in salt solution mining area. Attributing to the multidirection of water-soluble mining activities, the upper layer of the rock salt cavern is prone to overburden, or even serious collapse [2]. As long as the roof of the cavern uplifts to the ground surface, a large pit, which may cause potential damage to the nearby

Methods

Results

Discussion

Conclusion