PLUMAxys-a comprehensive model for ocean outfall dispersion

Abstract

An important tool in the assessment of ocean outfalls is the mathematical dispersion model. PLUMAxys has been designed as a comprehensive outfall dispersion model which may assess dispersion under a variety of environmental conditions and outfall configurations. It is capable of modelling effluents released from either single or multiport diffusers into a water column which may be stratified or unstratified. The column may be stagnant or flowing within a uniform or sheared current field. The density stratification and current speed and direction may also vary in space and time. PLUMAxys calculates the dispersion of the effluent plume from the outfall through the initial mixing region. The initial mixing region ends when vigorous mixing of the plume with ambient waters has subsided. The wastefield is said to be established and dispersion proceeds slowly thereafter. PLUMAxys predicts the degree of effluent dilution, the maximum rise of the effluent plume from the diffuser ports, the zone in which the plume is trapped, and the trajectory of the effluent from release to the establishment of the waste field flow regime.<>