Use of Time Series, Barometric and Tidal Analyses to Conceptualize and Model Flow in an Underground Mine: The Corning Mine Complex, Ohio
Understanding flow-system dynamics of underground coal mine complexes, such as the Corning mine complex that discharges acid mine drainage into Sunday Creek, is essential to designing in-situ remediation. Time series analysis is applied to the study of mine aquifers to characterize the systems between the input function (precipitation) and the output functions (discharge and head). Results are presented as correlograms, coherency diagrams, phase diagrams, and cross correlograms. The analysis of Corning discharge shows that the aquifer has a short response time and has a low storage capacity. A time lag of 3 to 4 days is found between precipitation and mine discharge, which corresponds to pressure pulse propagation and not to the actual advective flow of water. The results also demonstrate the important spatial heterogeneity of the aquifer and indicate that the mine does not behave as a single pool. Assuming porous-medium confined flow, barometric pressure and tidal signals are analyzed to yield mine aquifer properties. The analysis yields estimates of hydraulic conductivity, storage, barometric efficiency, and strain sensitivity. Comparison of the results with the available literature values indicates that the aquifer properties determined in this study have reasonable values. Parameter estimates are used to develop a numerical model of the Corning complex, using MODFLOW. The model simulates observed hydraulic head distributions and mine discharge rates with fair accuracy. The result of the simulations shows that 45% of the inflow to the mine complex derives from the surrounding coal strata, including detached mines. Travel time for water captured at subsidence captures is found to exceed 10 years, because of low gradients. It is finally concluded that a combination of time series analysis, barometric analysis and numerical modeling can provide useful information about the hydrogeology of a mine system prior to a large-scale and expensive in-situ remediation design.
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:time series analysis barometric and tidal flow modeling modflow underground coal mines acid mine drainage cornin complex southeast ohio
Date of Publication:01/01/2004