基于SBAS-InSAR的稀土矿区地表扰动监测

Rare Earth Mining Area Surface Deformation Monitoring Based on SBAS-InSAR

离子吸附型稀土矿区的开采与复垦,带来矿区地表的剧烈扰动和潜在的滑坡风险。本研究以岭北稀土矿区为例,基于长时间序列Sentinel-1A雷达影像,根据SBAS-InSAR技术原理利用奇异值分解方法获得研究区2017—2018年地表形变空间分布,并提取分析典型矿点坳背塘复垦地区和裸露地表高相干点形变时间序列特征,分析矿区扰动状况。研究表明:岭北稀土矿区地表处于不均匀的形变状态并且出现数个不同规模的形变区域;地表形变速率范围在-64.29165649 mm/a~46.84200287 mm/a;形变区域与稀土矿点具有较高的吻合性并且在时间维上的形变趋势基本一致。研究发现在坳背塘因稀土开采导致的裸露地表形变量大于复垦地区,最大累积形变量可达60.7593 mm,具有较高的扰动。结合因稀土开采方式造成的矿区荒漠化分布情况,发现地表形变与荒漠化相互关联,在荒漠化严重区域最大形变量可达69.0351 mm,进一步说明利用SBAS-InSAR技术在岭北稀土矿区地表形变监测中具有很好的应用前景。

In order to analyze the relationship between the surface deformation and distribution of ionic type rare earth ores due to mining, this study took the Lingbei rare earth mining area as the researched area, and used the long-term serial Sentinel-1 A radar images from 2017 to 2018 as data, and used singular value decomposition method based on the principle of SBAS-InSAR technology to have a result of the spatial distribution of surface deformation in the studied area, and extracted and analyzed the time series characteristics of surface deformation in the typical mining site of Aobeitang. The research shows that the surface of the Lingbei rare earth mining area is in an uneven deformation state and there are several deformation areas on different scales. The surface deformation rate ranges from-64.29165649 mm/a to 46.84200287 mm/a. The location of deformation area is highly consistent with the rare earth orebody site. Also, the deformation trend of the mining area in the time dimension is basically consistent with changing trend of the rare earth orebody. At the same time, combined with the distribution of desertification in the mining area caused by the mining method of rare earth orebody, it is found that the surface deformation is correlated to desertification. The maximum deformation in the severe desertification area can reach 69.0351 mm/a. The above results show that SBAS-InSAR technology has a good application prospect in detecting the surface deformation of the ionic type rare earth mining area.