The application of the Intermittent SBAS (ISBAS) InSAR method to the South Wales Coalfield, UK

Abstract

Satellite radar interferometry is a well-documented technique for the characterization of ground motions over large spatial areas. However, the measurement density is often constrained by the land use, with best results obtained over urban and semi urban areas. We use an implementation of the Small Baseline Subset (SBAS) methodology, whereby areas exhibiting intermittent coherence are considered alongside those displaying full coherence, in the final result, to characterize the ground motion over the South Wales Coalfield, United Kingdom. 55 ERS-1/2 Synthetic Aperture Radar (SAR) C-band images for the period between 1992 and 1999 are processed using the ISBAS (Intermittent Small BAseline Subset) technique, which provides 3.4 times more targets, with associated measurements than a standard SBAS implementation. The dominant feature of the observed motions is a relatively large spatial area of uplift. Uplift rates are as much as 1 cm/yr. and are centred on the part of the coalfield which was most recently exploited. Geological interpretation reveals that this uplift is most likely a result of mine water rebound. Collieries in this part of the coalfield required a ground water to be pumped to enable safe coal extraction; following their closure pumping activity ceased allowing the water levels to return to equilibrium. The ISBAS technique offers significant improvements in measurement density ensuring an increase in detection of surface motions and enabling easier interpretation.

Monitoring land motion due to natural gas extraction: Validation of the Intermittent SBAS (ISBAS) DInSAR algorithm over gas fields of North Holland, the Netherlands

“…deformation signal been present in the data a smoother more confident subsidence pattern would almost certainly have been observed, as was present in previous studies of spatially correlated motion using the technique (Bateson et al, 2015;Sowter et al, 2013;Sowter et al, 2016). and fig.…”

“…Results have greatly increased the density of measurements over regions largely dominated by rural land cover, leading to a more consistent overall coverage and a more confident interpretation. It has been used to determine surface movements in various application areas including; coal extraction in the UK (Sowter et al, 2013, Novellino et al, 2014a, Bateson et al, 2015, landslips in Italy (Novellino et al, 2014b), elevation changes associated with blanket peat in Wales (Cigna et al, 2014) and groundwater abstraction in Mexico (Sowter et al, 2016).…”

“…The ISBAS algorithm has previously been validated by contextual comparisons only, where the pattern of ground motion correlates with the geology and, in some cases, appears bound by existing fault structures (Bateson et al, 2015). This has essentially been motivated by the lack of historical survey observations in the vegetated classes.…”

“…Prior studies using the ISBAS method have demonstrated that the spatial extent of ISBAS velocities is improved and the patterns of land motion correlate to geology (Sowter et al, 2013;Bateson et al, 2015).…”

On the Use of the ISBAS Acronym in InSAR Applications. Comment on Vajedian, S.; Motagh, M.; Nilfouroushan, F. StaMPS Improvement for Deformation Analysis in Mountainous Regions: Implications for the Damavand Volcano and Mosha Fault in Alborz. Remote Sens. 2015, 7, 8323–8347

“…We offer a wide selection of references below [2][3][4][5][6][7][8], each of which clearly identifies the ISBAS acronym as Intermittent SBAS. The first peer-reviewed journal [2] in this instance was in 2013 and so the use of the acronym certainly predates the Vajedian et al reference by at least two years.…”