Risk analysis in environmental systems

Uncertainty is an inherent feature of environmental systems, which makes probabilistic models important. Environmental risk assessment is an important but time consuming task. For large-scale systems, use of linear systems with uncertainty information on parameters and inputs is one of the few possible methods to assess risk. To estimate risk, it is necessary to have at least the first two moments of output variables. This paper describes an efficient method developed for second-moment analysis of linear systems with uncertain coefficients. The main objective is to provide the means and the variances of the output and to provide efficient formulation and automation of the moment equations. This method is demonstrated in two real-world applications of environmental modeling.Key words: uncertainty, second-moment methods, risk analysis, reliability, linear systems.