Using the GRAM Model to Reconstruct the Important Factors in Historic Groundwater Rebound in Part of the Durham Coalfield, UK

Abstract

Modeling of mine water rebound in the southernmost zone of the Durham Coalfield has been undertaken in an attempt to reproduce observed water level recovery, since the 1970s, within five coal blocks south of the Butterknowle Fault. The lumped parameter model GRAM (groundwater rebound in abandoned mineworkings) was chosen to perform the simulations since it overcomes, to a large extent, a common problem found in such studies, namely a lack (especially concerning historic hydrogeological records) and superabundance of various kinds of data. The results obtained from this approach are satisfying and closely resemble the observed pattern of mine water rebound for the mining blocks studied. Such research indicates the critical dependence of predictions on factors such as the volume of water flowing into the system, the percentage runoff, and the value of storage coefficient assigned to the old workings. Model predictions are most useful as a tool for improving the conceptual understanding of abandoned mine systems and as a basis for evaluating alternative possibilities of coalfield behaviour, rather than as a strict quantitative assessment for all management purposes.Mine Water and the Environment (2007) 26: 60-69 © IMWA Springer-Verlag 2007

The Occurrence and Quality of Mine Water in the Upper Silesian Coal Basin, Poland

“…Some of these disturbances may be Mine Water Environ (2009) 28:232-244 235 permanent (changes in subsurface transmissivity and storage) while some are more temporary in nature (the dewatering of mines, desaturation of adjacent strata, and induced steep head gradients in the saturated strata adjacent to and above the mine). Once pumping has ceased, ground water floods the mine and the zone of depressed head in the rocks adjacent to the mine rebounds (Gandy and Younger 2007;Kortas and Younger 2007). As mine flooding progresses, the sulphate-and metal-contaminated mine water can flow into adjacent aquifer strata, causing widespread ground water pollution (Neymeyer et al 2007;Razowska 2001).…”

Approaches of Applying Non-Darcian Flow Equations to Predicting Groundwater Rebound in Response to Coal Mine Closure

“…. Several studies using the GRAM model have been carried out to analyze the mine groundwater rebound phenomenon associated with a coal field in South Yorkshire, UK (Gandy & Younger 2007;Kortas & Younger 2007). The GRAM model considers water in each pond to be completely mixed and the ponds to be interconnected with horizontal pipes.…”

Discussion of “Oil and gas wells and their integrity: Implications for shale and unconventional resource exploitation” by R.J. Davies, S. Almond, R.S., Ward, R.B. Jackson, C. Adams, F. Worrall, L.G. Herringshaw, J.G. Gluyas and M.A. Whitehead. (Marine and Petroleum Geology 2014)

“…Again, the contrast with coal mines is telling -they generally ARE inter-connected all the way back to outcrop, and that is why we get significant water discharges from them (e.g. Kortas and Younger 2007;Gandy and Younger 2007); it is also noteworthy that once mine workings are drowned by rising groundwaters, any release of methane from them abruptly ceases (e.g. Hall et al 2005; Younger 2014) -there is no reason why depleted unconventional gas reservoirs should behave any differently when groundwater heads within them recover.…”