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 versatile method for making such estimates when used to minimize the residuals sum of squares between calculated and observed data points. Examples of the method applied to Pick's Second Law, the advection dispersion equation, and the integrated Monod kinetics equation illustrate its utility. Compiled programs have been developed, and are available on request, for the estimation of diffusion coefficients, contaminant transport parameters (average linear ground‐water velocities, dispersivities, porosities), and biodegradation kinetic constants.