GGSD Program Details for CXTFIT

CXTFIT

Category	Parameter estimation
Publisher	Virginia Tech (Civil Engineering)
Platform	DOS
Status	Freeware
Description	CXTFIT is used for parameter estimation for 1D dissolved transport models. A collection of solutions for 1D dissolved phase transport, which can be run in two modes: 1) compute the solution for a known set of parameters or 2) determine unknown parameters from measured concentration data. Based on a non-linear least-squares inversion method and can be used to identify several parameters in a number of different 1D solute transport models. Includes: convection-dispersion transport equation with terms accounting for linear equilibrium adsorption, zero-order production and/or first-order decay; a two-site/two-region model is included that can be applied to various non-equilibrium transport problems; a stochastic model that considers the effects of areal variations in hydraulic fluxes on field-scale solute transport with zero- or first-order production or decay or both. The least-squares inversion method can be used to analyse both spatial and temporal distributions of flux or resident concentrations. Includes pre-processor and post-processor, source and executable code, example data files and documentation.
Cost	Free on www
Data formats supported	None stated
Supplier in United States of America	International Ground Water Modeling Center
Supplier in United States of America	USDA Salinity Laboratory