Nuclear techniques for monitoring sediment dynamics in the coastal zone

Abstract

The knowledge of sediment transport in the coastal region is of vital importance to the management of this critical interface between land and sea, where most of the world population lives. For the assessment of sediment behaviour, hydraulic and sediment measurements, bathymetric survey, mathematical and physical models, are applied. Sediment tracers provide a unique capability for understanding sediment transport assisting in sediment management which cannot be obtained any other way, whether conventional monitoring or physical and numerical models because tracers integrate all the hydrodynamic actions in time and space. Computational fluid dynamics (CFD) is now an essential tool for the management of the natural systems and is increasingly used to study the fate and behaviour of particulates and contaminants. Tracer techniques are often employed to validate hydrodynamic models to enhance confidence in the predictive value of the models. In-situ detection afforded by the use of a radioactive tracer allows accurate quantitative determination of the rate of sediment transport, compared with other tracer methods. Also, it is cost effective and safe: its radiological impact to the environment is minimal. Several case studies, performed in different regions of the world, are presented.