GGSD Program Details for ASM

ASM

Category	Contaminant transport (2D FD)
Publisher	Swiss Federal Institute of Technology (Hydro)
Platform	DOS
Status	Freeware
Description	ASM (Aquifer Simulation Model) is a 2D numerical flow and transport model. The flow equation is solved using a node-centered finite difference method. The resulting algebraic equations can be solved using either the iterative alternating direction implicit method or the conjugate-gradient method. Computation of pathlines and isochrones by Prickett (Random-Walk) and Pollock (MODPATH model) methods. Solute transport is simulated by the Random-Walk method. Steady-state and transient flow conditions, with confined, phreatic, and leaky-confined conditions. Transport is based on a steady-state flow field. Heterogeneous and anisotropic aquifer. Options for time-varying pumping and injection rates in wells, temporally and spatially variable recharge, permanent or instantaneous solute injection, and infiltration or exfiltration of surface water. Models mass balance. Grid of up to 60 X 60 cells. Originally developed as an educational tool, it incorporates many features of more complex models, suitable for initial evaluations of hydrogeologic problems. Menu-driven, interactive user-interface. Includes on-screen graphical options including head contours, concentration distributions, velocity vectors, pathlines, and isochrones. Output includes head and concentration files for post-processing with a commercial contouring package, and time series for heads and concentrations in HPGL format. Includes the source code, runtime version and user's manual.
Cost	Free on WWW
Data formats supported	Printer : HPGL
Supplier in Switzerland	Swiss Federal Institute of Technology (Hydro)