EXTENDED ABSTRACT

This paper presents the identification and quantification of uncertainty in nutrient load estimates for the Goulburn-Broken catchment from irrigation drains. The reliable estimation of pollutant loads is a difficult task since, typically, water quality data is relatively sparse. The sparse nature of the data means that some estimation technique must be applied, based on assumptions about the behaviour of pollutant concentrations instream in the times when water quality was not sampled. Twenty two methods of estimating annual nutrient loads have been identified and compared in this study. The results vary significantly and show that the choice of estimation method contributes to the overal