Sentinel-1A在西南煤矿区地表沉陷监测中的适用性分析

Applicability analysis of sentinel-1A in surface subsidence monitoring in southwest coal mining area

地表沉陷对人类安全生产和生活造成严重影响,而非法采煤活动更易导致此类事件的发生,研究如何高效地对地下采煤活动进行监测具有重要意义.本文从面散射去相关、体散射去相关和形变梯度三个方面,分析了Sentinel-1A在盘州市地下采煤导致的地表沉陷监测中的适用性;使用干涉相位图计算形变区边界及其相位形变梯度,与参考图形和参考梯度进行相关性计算并设置阈值,以提取地下采煤导致的地表沉陷范围.结果表明:(1)Sentinel-1A抗地形坡度去相关能力强,临界坡度范围为[39.24°,39.32°];(2)植被是影响相干性的重要因素,NDVI植被指数与干涉相干系数呈显著负相关,R^(2)为0.59;(3)盘州市煤矿采区外围的地表形变梯度小于1.4×10^(3),在Sentinel-1A的可监测范围之内;(4)基于DInSAR解缠相位提取的矿区形变范围皆位于SBAS-InSAR监测的矿区形变范围之内,进一步表明该方法在西南煤矿区地表沉陷监测中具有适用性,为西南煤矿区非法地下采煤监测提供了一种高效的方法.

The surface subsidence will affect the safety production and life of human beings,while the illegal mining activities are more likely to lead to such incidents.Therefore,it is necessary to study how to monitor coal mining activities efficiently.In this paper,the applicability of Sentinel-1 A in the monitoring of surface subsidence caused by underground coal mining in Panzhou city was analyzed from three aspects:surface scattering decorrelation,volume scattering decorrelation and deformation gradient.After that,the phase deformation gradients and settlement area boundaries were calculated according to the interferometric phase map,and then the correlation calculation was carried out by combining the reference gradient and the reference figure so as to extract the surface subsidence ranges caused by underground mining.Finally,the recognition results were superimposed and compared with the SBAS-InSAR monitoring results to verify the accuracy of the recognition results.The results show that:(1)Sentinel-1 A has strong anti-terrain slope decorrelation ability,and the critical slope ranges from 39.24°to 39.32°.(2)Vegetation is an important factor affecting coherence,and NDVI vegetation index is negatively correlated with interferometric coherence coefficient(R^(2)=0.59).(3)The surface deformation gradient of the periphery of panzhou coal mining area is less than 1.4×10^(3),which is within the monitoring range of Sentinel-1 A.(4)The extracted deformation ranges of mining area based on DInSAR unwrapped phase are within the deformation ranges of SBAS-InSAR monitoring results,which further shows that this method is applicable to the surface subsidence monitoring in southwest coal mining area,and provides an efficient method for the monitoring of illegal underground coal mining in southwest coal mining area.