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Darcy's Law Groundwater Flow Calculator
Calculate a one-dimensional saturated-groundwater-flow approximation from two total hydraulic heads, the distance between them, hydraulic conductivity, and cross-sectional area. Both heads must reference the same vertical datum and measuring convention. The hydraulic-gradient magnitude is i = |h1 - h2| / L, and idealized flow is from higher total head toward lower total head. In vector notation Darcy's law is q = -K i, where the negative sign denotes decreasing-head direction; this calculator reports the positive flux magnitude q = K i and states the inferred one-dimensional direction separately. Volumetric discharge is Q = q A. Darcy flux, also called specific discharge, has velocity units but divides discharge by the full cross-section including solids, so it is not average pore-water speed. When a representative effective porosity is supplied, average linear velocity is approximated as v = q / ne. Effective porosity represents interconnected flow space at the relevant scale and must not be replaced automatically with total porosity, which can include isolated or poorly connected pores. Hydraulic conductivity may be entered in metres per second, metres per day, centimetres per second, or feet per day. Area may be entered in square metres or square feet; GeoMiner converts internally before reporting cubic metres per second, cubic metres per day, litres per second, cubic feet per day, and U.S. gallons per minute. Hydraulic conductivity is a combined property of the porous medium and fluid. It can change with position, direction, scale, saturation, temperature, density, viscosity, fractures, and test method. A scalar one-dimensional calculation assumes the selected conductivity, gradient, flow length, and area represent the same domain. Heterogeneity, anisotropy, layered media, preferential fracture flow, unsaturated conditions, variable-density flow, nonlinear regimes, and three-dimensional boundaries require other treatment. Two head observations do not establish a regional groundwater-flow vector. Static arithmetic also omits transient recharge, pumping, storage, leakage, surface-water interaction, changing boundaries, dispersion, sorption, reactions, and parameter uncertainty. The result does not establish well yield, drawdown, dewatering performance, capture zones, contaminant arrival, discharge boundaries, seepage safety, engineering design, regulatory