基于SBAS-In SAR的地表沉降监测及漏斗拟合分析

Monitoring of surface subsidence and funnel fitting analysis based on SBAS-InSAR

近年来,In SAR技术凭借其测量范围广、精度高及便捷高效等优势,已被广泛应用于矿区的沉降监测中。利用InSAR技术研究矿区的沉降漏斗所采用的主要模型有Logistic模型、Knothe模型等,这些多以沉降量预测为主,且模型计算相对复杂,在三维可视化表达方面也相对较少。因此,本文提出一种采用椭圆锥拟合矿区沉降漏斗的方法,用于揭示矿区开采时地表沉降的时空演化特征。首先,基于SBAS-InSAR技术处理Sentinel-1A影像数据获取矿区的时序沉降结果;其次,将不同时期的沉降结果转化为栅格数据,利用椭圆锥模型拟合沉降漏斗,获取椭圆锥参数;最后,采用线性拟合的方式拟合不同时期椭圆锥的参数变化,研究矿区沉降过程中的时空演化规律,并用验证点证实监测结果的可靠性。结果表明,本方法能够用于快速模拟和分析矿区工作面附近的沉降漏斗,从而有效揭示沉降过程中的三维时空演化规律。研究成果能够为地质灾害防治、沉降治理等提供科学的参考依据。

In recent years,interferometric synthetic aperture radar(InSAR)technology has been extensively employed in the monitoring of mining subsidence due to its wide measurement range,high precision,and efficiency.The primary models used for studying mining subsidence funnels using InSAR technology include the Logistic model,the Knothe model,among others.These models mainly focus on predicting the magnitude of subsidence,with less attention paid to the planar variation of subsidence.Additionally,the computational processes for these models are relatively complex,and there is limited application of three-dimensional visualization.Therefore,this paper proposes a method for rapidly fitting mining subsidence funnels using an elliptical cone to reveal the spatiotemporal evolution characteristics of surface subsidence during mining.Firstly,time-series subsidence results of the mining area are obtained by processing Sentinel-1 A image data using SBAS-InSAR technology.Then,the subsidence results from different periods are converted into raster data,and an elliptical cone model is used to fit the subsidence funnel,obtaining the elliptical cone parameters.Finally,linear fitting is applied to the parameter changes of the elliptical cones over different periods to study the spatiotemporal evolution of subsidence during mining,and verification points are used to confirm the reliability of the monitoring results.The results show that in 2023,subsidence within the mining area predominantly transpired around the 3308 and 3206 working faces,with maximum subsidence values reaching 466 mm and 377 mm respectively.The subsidence funnel,fitted using an elliptical cone,categorises the subsidence process in the 3308 working face area into three stages:Stage I corresponds to the period of retreating face,during which the expansion and sinking rates of the subsidence funnel remain relatively stable.The long and short axes at the bottom of funnel and the rate of sinking increase at 2.97 m/day,2.31 m/day,and 1.96 mm/day respectively.Stage II corresponds to the residual subsidence period after the end of face mining,where the expansion and sinking rates of the funnel significantly decrease.The long and short axes at the bottom of the funnel and the rate of sinking increase at 1.35 m/day,1.76 m/day,and 0.78 mm/day respectively.Stage III corresponds to the decay period of subsidence,approximately four months after the cessation of face mining,where the surface subsidence area gradually stabilises.The long and short axes at bottom of the funnel and the rate of sinking increase at 0.63 m/day,1.24 m/day,and 0.81 mm/day respectively.Despite persistent residual subsidence over a prolonged duration,it remains relatively stable overall,requiring long-term monitoring.Verification of these monitoring results using validation points confirms their relative reliability.Addressing the complexity of previous methods for fitting mining subsidence funnel models,which primarily focused on subsidence prediction and offered limited three-dimensional visualization,this paper proposes an elliptical cone fitting approach for simulating and analyzing subsidence funnels near mining faces.This method enables rapid display of the three-dimensional spatiotemporal evolution characteristics of mining subsidence bodies,providing fast calculations and ease of use.It effectively analyses the spatiotemporal evolution patterns of surface deformation in mining areas,offering a scientific reference for geological disaster prevention and subsidence management.