Advanced DInSAR analysis on mining areas: La Union case study (Murcia, SE Spain)

Abstract

The town of La Union (SE, Spain) is located within a metal mining area that has been exploited since the Roman period. This historic exploitation has left behind a high concentration of abandoned underground mining galleries. Currently, an industrial area is subsiding due to the collapse of one of these galleries in May 1998. In this paper, an advanced Differential Interferometry SAR (DInSAR) method called the Coherent Pixels Technique (CPT) has been used to study the subsidence phenomena for two time intervals, from January 1998 Results obtained in the city of La Union have shown that the advanced DInSAR technique is able to provide very useful spatial and temporal deformation data for the measurement of small scale subsidence throughout short time periods. This technique has enabled the temporal evolution of the phenomena in the city of La Unión to be studied and understanding of subsidence to be expanded beyond the limits of a deployed topographical control network, in a more cost effective way than classical methods.

Application of DInSAR in Mine Surface Subsidence Monitoring and Prediction

“…Many authors have reported that the DInSAR results have shown good agreement when compared with groundbased measurements 4,13,14,16,34,35,37,42,45,58,59,61,66,67 and provide reliable estimates of subsidence, particularly in an urban environment. A comparison of precise levelling and persistent scatterer SAR interferometry has been done 58,59 and PSI results show good agreement with the levelling data.…”

“…Herrera et al 44 using CPT and TerraSAR-X data while monitoring an urban subsidence in Murcia, Spain, have reported an average rate of subsidence from -5 mm/yr to -35 mm/yr. In another study using CPT, Herrera et al 37 while monitoring metal mining area in Murcia, have demonstrated that deformation values with DInSAR (using ERS 1/2 and Envisat images) on comparison with the topographical levelling network measurements of the same period gave an absolute average difference of 0.7 cm with a standard deviation of 0.5 cm.…”

“…A slow and local phenomenon of subsidence due to underground coal mining was identified near Gardanne, France by Carnec and Delacourt 4 from images acquired by ERS-1/ERS-2 satellites between 1992 and 1995. Interferometric monitoring has shown that the impact of subsidence on the surface migrated all along the path of advancement of the underground operations establishing a direct relationship between them 4,26,35,37 . The application of SAR interferometry to identify surface displacements through DInSAR has shown its great potential and has developed manifold over the last decade.…”

“…The results showed that high accuracy could be obtained using this technique to monitor the deformation of a large area. Another DInSAR technique, the coherent pixel technique (CPT) was applied for the study of displacements 37,43,44 . This technique is based on the pixel selection criterion, a coherence threshold and non-restricted generation of the interferometric pairs.…”

DInSAR measurements of ground deformation by sinkholes, mining subsidence, and landslides, Ebro River, Spain

“…54 Most of the geodetic techniques, including GPS, allow measuring recent short- The technique was first applied to single deformation events such as ground 64 motion in agricultural fields related to changes in the soil moisture caused by irrigation 65 (Gabriel et al, 1989) or ground displacement associated with the 1992 Landers, 66 California earthquake (Massonet et al, 1993). Subsequently, differential SAR 67 interferometry has been used to study different types of surface deformation, including 68 active faulting and preseismic, coseismic and postseismic displacements (Massonnet et Herrera et al, 2007), multiyear and seasonal uplift and subsidence controlled by 75 groundwater withdrawal and recharge (Amelung et al, 1999;Galloway et al, 1998;76 Hoffman et al, 2001), shrink-swell cycles in soils related to rainfall (Massonnet and 77 Feigl, 1998), the identification and anticipation of sinkholes in karst areas (Baer et River valley (Quirantes, 1978). Figure 5) and with the maximum number of significant rainfall events (>20 mm) over 481 the periods studied.…”