Ground Motion in Areas of Abandoned Mining: Application of the Intermittent SBAS (ISBAS) to the Northumberland and Durham Coalfield, UK

Abstract

In this paper, we investigate land motion and groundwater level change phenomena using differential interferometric synthetic aperture radar (DInSAR) over the Northumberland and Durham coalfield in the United Kingdom. The study re-visits earlier research that applied a persistent scatterers interferometry (PSI) technique to ERS (European Remote Sensing) and ENVISAT (Environmental Satellite) data. Here, the Intermittent Small Baseline Subset (ISBAS) DInSAR technique is applied to ERS, ENVISAT and Sentinel-1 SAR datasets covering the late 1990s, the 2000s and the mid-2010s, respectively, to increase spatial coverage, aid the geological interpretation and consider the latest Sentinel-1 data. The ERS data identify surface depressions in proximity to former collieries, while all three data sets ascertain broad areas are experiencing regional scale uplift, often occurring in previously mined areas. Uplift is attributed to increases in pore pressure in the overburden following the cessation of groundwater pumping after mine closure. Rising groundwater levels are found to correlate to ground motion measurements at selected monitoring sites, most notably in the surrounding area of Ashington. The area is divided by an impermeable EW fault; to the south, surface heave was identified as groundwater levels rose in the 1990s, whereas to the north, this phenomenon occurred two decades later in the 2010s. The data emphasize the complexity of the post-mining surface and subsurface environment and highlight the benefit that InSAR, utilizing the ISBAS technique, can provide in its characterization.

Evolution of Secondary Deformations Captured by Satellite Radar Interferometry: Case Study of an Abandoned Coal Basin in SW Poland

“…The phenomenon of post-mining ground surface and subsidence is referred to as secondary deformations [37,38]. Phenomena similar to those observed in the Walbrzych region were observed with the use of the InSAR methods also in France, Germany, Belgium, and England [1,2,10]. The application of InSAR methods in the detection of ground surface activity in post-mining areas was also discussed in [39][40][41][42].…”

“…Finally, Gee et al [10] followed their earlier investigations on abandoned coal fields in the United Kingdom (NE England) using the Intermittent Small Baseline Subset (ISBAS) DInSAR (Differential InSAR) technique on ERS 1/2, ENVISAT, and Sentinel-1 SAR images. They observed uplift of the ground that was attributed to increases in pore pressure in the rock mass following the cessation of groundwater pumping after closure of the mine.…”

Observing Geohazards from Space

“…Moving from optical to Synthetic Aperture Radar (SAR) satellite imagery, the Invited Feature Paper by Gee et al [9] presents a multi-mission study of land motion and groundwater level change in areas of abandoned mining in the UK using a 21-year long series of ERS-1/2, ENVISAT and Sentinel-1 satellite SAR data in C-band. The authors employ a modified version of the Small BAseline Subset (SBAS) technique allowing extraction of ground motion information across most land cover types, and identify surface depressions in proximity to former collieries and broad areas experiencing regional scale uplift.…”

Application of satellite radar interferometry (PSINSAR) in analysis of secondary surface deformations in mining areas case studies from Czech Republic and Poland

“…They observed correlation between varied rates of ground uplift and changing water levels in individual coal fields forming water-basins separated by faults. Gee et al (2017) followed their earlier investigations on abandoned coal fields in the United Kingdom (NE England) using the Intermittent Small Baseline Subset (ISBAS) DInSAR technique on ERS-1/2, Envisat, and Sentinel-1 SAR images. They observed uplift of the ground attributed to increases in pore pressure in the rock mass following the cessation of groundwater pumping after mine closure.…”

“…Notable applications of SAR interferometry in studies of secondary deformations in post-mining areas have been described by Abdikan et al (2014), Bateson et al (2015), Caro-Cuenca et al (2013), Gee et al (2017), Mei et al (2007), Raucoules et al (2007), and Samsonov et al (2013), among others. These examples show the scope of InSAR applications for mining related ground movement studies that include application of a variety of SAR sensors, different processing techniques, different mining sites, and diverse goals of these studies.…”