- USGS Codes: Including
SHARP (Finite-difference model of quasi-3d freshwater and saltwater
flow with sharp interace), SUTRA (2D, 3D, variable-density, variably-saturated
flow, solute or energy transport), SEAWAT (3D variable-density
ground water flow), MOC (2D and 3D flow and transport; 2D, 2-constituent,
variable density ), HST3D (3D finite-difference model of ground-water
flow with heat and solute transport), and other programs.