Uncertainty Analysis of the Niagara River Hexachlorobenzene Toxic Concentrations

摘要

This paper presents some preliminary results of the application of an analytical solution to a one-dimensional advective-dispersive-reactive equation accounting for input from Lake Erie and other point and non-point discharges as well as for transport and kinetic processes along the Niagara River. The objective of this paper is to compare the modeled toxic concentrations of Hexachlorobenzene (HCB) at the exit of the Niagara River, with the field measurements taken at the same location. This comparison is performed in terms of probabilistic analysis. The uncertainty of the model output is estimated from the uncertainty of the stochastic variables and parameters used in the model. The uncertainty analysis provides a better understanding of the influence the stochastic model components have on the overall final results. Estimation of this uncertainty is performed by means of the First-Order- Second-Moment Method (FOSM). Risk and reliability analysis is introduced here as a tool to aid in defining waste discharge limits at the point and non-point source level that would enable fulfillment of the established water quality criteria. The results of the uncertainty analysis of the Niagara River HCB toxic loadings can be a valuable instrument for assessing the kinetic and transport processes along the River and offers a starting point for improvement on the traditional deterministic modeling work.