A statistical method for the estimation of trend in salinity in the river Murray

Abstract

A simple statistical model is proposed for the analysis of salinity measurements, and is illustrated in detail for chloride concentrations in the River Murray at Morgan, S.A., over a period of 43 years. We conclude that a positive trend has occurred over and above that associated with a decline in waterflow. Some insight into the form of the trend is provided by a moving average of the log-chloride concentration after allowing for waterflow effects. Despite such extensive data, the linear component of this trend is not precisely established, as is clear from the wide confidence limits.