Parameter identifiability of an erosion simulation model

Abstract

An erosion simulation model based on the kinematic equations of flow and advective transport of sediment with rill and interrill source terms is written in a finite difference form. The accuracy of the numerical solution is examined using the analytical solutions to the model for some special cases. The parameter identifiability of the model is examined using contour plots of the objective function response surface. The erosion equation is non-dimensionalized to allow for the examination of all parameter combinations. Two optimization routines are used to identify parameters for theoretical, theoretical with added error, and observed sediment concentration data. The finite difference formulation used is a suitable numerical scheme for this type of erosion model. Parameter identifiability of this erosion model is difficult because of parameter insensitivity and parameter interactions for some cases. Both the numerical scheme and the random error have little effect on parameter identifiability.