Finite-Element Grid
The grid is specified in terms of triangular prisms and facilitates representation of complex geometries and highly-variable spatial discretization, which is particularly useful for mining applications with complex geologic structures and steep hydraulic gradients.
Progressive Geometry
The elevation of nodes of the finite-element grid can be defined to vary through time. This enables more accurate representation of the underground workings and open pits according to the mine schedules being evaluated.
Saturated/Unsaturated Flow
The finite-element grid can remain fixed through time (with the exception of excavations), and the saturated flow domain can change through time in accordance with changes in the water table, further facilitating representation of the spatial hydrogeologic variability of the groundwater system without additional computational overhead of solving unsaturated flow equations.
3D Graphics
Represent geology, model domain, pit geometry, groundwater heads, and pore pressures in 3D.
Flexible Boundary Conditions
Boundary
conditions can be represented as specified-head, specified-flux, and
internal source-sink terms (each of which can be variant or invariant
with time), or as variable-flux boundaries that simulate time-variant
fluxes in response to changing boundary heads and an infinite aquifer.
Very Transmissive Zones
By
defining links between specific node pairs with enhanced conductivity,
very transmissive zones can be used to accurately represent tunnels,
underground workings, declines, conductive faults, wells pumping from
multiple layers, etc.
Groundwater/Surface-Water Interaction
Streams
are simulated as river networks of hydraulic compartmentalization and
the model simulates river depletions and additions from exchange with
groundwater.
Evaporation/Evapotranspiration
Loss
of water from bare/vegetated soils can be simulated and is proportional
to the distance between the ground surface and water table, with
maximum evaporation rate and extinction depth as constraints.
Pit Lakes
Excavation
and pit-lake infilling of multiple pits can be simulated within the
same model domain and their respective mining schedules represented
simultaneously. The model also provides node-bynode fluxes into/out of
the pit lake, evaporation and precipitation on the lake surface, and
predictions of lake stages as a function of time, which can readily be
used to predict detailed hydrodynamic and geochemical pit-lake
conditions and to predict pit-wall seepage during mining.
Time-Variant Conductivity
Can
be used to represent the zone of relaxation around excavations,
backfilling operations, longwall and room-and-pillar coal mining,
freeze-thaw conditions, or other scenarios where hydraulic conductivity
may change during the simulation period.
Numerically Stable
Due
in part to the finite element grid and the numerical methods applied in
the model, MINEDW is typically very stable numerically. This is
particularly important in cases where there is a high degree of
hydraulic compartmentalization with steep hydraulic gradients.
