Sensitivity analysis techniques for calibration and reduction of environmental models

Abstract

Abstract A recently developed approach is applied for calibration and reduction of a water quality model. The method consists of a combination of the Generalised Likelihood Uncertainty Estimation technique (GLUE) and Global Sensitivity Analysis (GSA) . The method is based on multiple model evaluations. The GSA is a quantitative, model independent approach and is based on estimating the fractional contribution of each input factor to the variance of the model output, also accounting for interaction terms. Using GLUE, the model runs are classified according to a likelihood measure, conditioning each run to observations. With GSA, model parameters driving calibration are clearly highlighted, also when strong interaction between parameters is present.