Visual MODFLOW is often used to model the groundwater conditions at mine sites. These models are intended to assist in the decision making process for issues that are controlled or affected by groundwater. A groundwater model can be used to describe the groundwater flow system at the mine site (Kuchling et al.), assess impacts of various activities such as mine dewatering or baseflow reduction, assess potential exposure to groundwater contamination (Tiwary et al.) and assess mitigation options, and communicate information to regulators and stakeholders.
The creation of a groundwater model in Visual MODFLOW Flex requires site data ranging from a description of the subsurface geology, to flow properties such as a hydraulic conductivity field of the model site and monitoring data (flow and concentrations) for calibration. Depending on the model complexity, available data may be sufficient to create a reasonable groundwater model however; ongoing data collection as the mine project progresses may be used to update the model and improve model confidence.
During the production phases of mining, groundwater models may be used in conjunction with 3D geological block models to determine the effects of mine production on the water table. Visual MODFLOW Flex heads can be displayed in some of the more common mine design and production applications (e.g. MicroMine). This can be easily done by exporting the groundwater heads at each grid cell center for a specified output time (30 days, 60 days, 300 days, etc.) to correspond with the predicted mine production at this time. Using these types of software applications together, predictions can be made as the mine is developed to determine if flooding will occur in tunnels or an open pit or if exposure has been compromised.
References
Kuchling, K., Chorley, D., Zawadzki, W. Hydrogeological Modeling of Mining Operations at the Diavik Diamonds Project. In: Environmental Issues and Management of Waste in Energy and Mineral Production. 689-696. 2000.
Tiwary, R.K., Dhakate, R., Anando Rao, V., and Singh, V.S. Assessment and Prediction of Contaminant Migration in Ground Water from Chromite Waste Dump. Environmental Geology. Volume 48, August 2005. 4-5:420-429.