Robust global sensitivity analysis of a river management model

Abstract

The simulation of routing and distribution of water through a regulated river system with a river management model will quickly results in complex and non-linear model behaviour. A robust sensitivity analysis increases the transparency of the model and provide both the modeller and the system manager with better understanding and insight on how the model simulates reality and management operations. In this study, a robust, density-based sensitivity analysis, developed by Plischke et al. (2013), is applied to an eWater Source river management model. The sensitivity analysis is extended to not only account for main but also for interaction effects and is able to identify major linear effects as well as subtle minor and non-linear effects. The case study is an idealised river management model representing typical conditions of the Southern Murray–Darling Basin in Australia for which the sensitivity of a variety of model outcomes to variations in the driving forces, inflow to the system, rainfall and potential evapotranspiration, is examined. The model outcomes are most sensitive to the inflow to the system, but the sensitivity analysis identified minor effects of potential evapotranspiration as well as non-linear interaction effects between inflow and potential evapotranspiration.