A SIMPLE AND POWERFUL METHOD OF PARAMETER-ESTIMATION USING SIMPLEX OPTIMIZATION

The need for objective parameter estimates is common in hydrogeology. The simplex optimization algorithm provides a fast, simple, and versat ile method for making such estimates when used to minimize the residua ls sum of squares between calculated and observed data points. Example s of the method applied to Fick's Second Law, the advection dispersion equation, and the integrated Monod kinetics equation illustrate its u tility. Compiled programs have been developed, and are available on re quest, for the estimation of diffusion coefficients, contaminant trans port parameters (average linear groundwater velocities, dispersivities , porosities), and biodegradation kinetic constants.