Using Time Series Analysis of Coal Mine Hydrographs to Estimate Mine Storage, Retention Time, and Mine-pool Interconnection

Abstract

Understanding flow-system dynamics of underground coal mine complexes is essential to designing in-situ remediation. Such complexes can be studied by applying time series analysis to the precipitation series and well and mine discharge hydrographs. The Corning mine complex discharges acid mine drainage into Sunday Creek in Ohio, USA. Analysis of the Corning discharge shows that the aquifer has a short (9 days) response time and has little capacity for long-term storage. A time lag of 3-4 days occurs between precipitation and discharge, which corresponds to pressure pulse propagation displacing stored mine water, rather than actual advective flow of water. A gradual decline in hydraulic head is observed from the unsaturated recharge area to the fully flooded discharge area. All well hydrographs show a similar seasonal trend, with mine water levels peaking in early summer, and reaching their lowest levels in early fall, consistent with seasonal recharge patterns. A relatively isolated and fully saturated portion of the mine is sensitive to diurnal barometric pressure, as is typical of confined aquifers, with well water level declining as pressure increases. Other portions of the mine behave as unconfined aquifers, insensitive to barometric pressures. The results also demonstrate the important spatial heterogeneity of the aquifer and indicate that the mine does not behave as a single pool.

Mine Flooding History of a Regional Below-Drainage Coalfield Dominated by Barrier Leakage (1970–2014)

“…The best evidence for pump operation is the mine water level data themselves; when pumps operate, they often maintain a uniform or declining water level, and when pumps are turned off, water levels generally rise until either a discharge or control elevation is attained. Thus, changes in pump operation manifest themselves as changes in slope on a hydrograph, adding to the utility of water level measurements for interpreting mine hydrology (e.g., [24]). Some records of pumps being either turned off or turned on were available from operators.…”

Incorporating Hydrologic Uncertainty in Industrial Economic Models: Implications of Extreme Rainfall Variability on Metal Mining Investments

“…No seasonal patterns of water flows (e.g. Fernández-Álvarez et al 2016;Sahu et al 2009) or possible discrete changes in water flows (Rapantová et al 2012) were considered. In the case of an operating mine, these characteristics could be derived from measured Brennan and Schwartz (1985a, b), a metal mine can be valued analogically to a financial option.…”

Effects of urbanization and stormwater control measures on streamflows in the vicinity of Clarksburg, Maryland, USA

“…We use a modified unit hydrograph (UH) approach to model discharge response to an instantaneous basin‐wide unit precipitation event. The UH is a linear temporal transfer function based on covariance between ‘effective’ precipitation, from which some abstraction has been made from the observed precipitation, and time‐lagged discharge (Guang‐Te and Yu, ; Panagopoulos and Lambrakis, ; Sahu et al ., ). The derivation of a UH is complicated by varying antecedent conditions (Schilling, ; Ahsan and O'Connor, ; Astatkie et al ., ; Astatkie and Watt, ), groundwater interactions (Singh, ; Labat et al ., ) and apparent non‐causal correlations attributed to latent or uncharacterized influences on the rainfall–runoff dynamic.…”