Applications and impact of radiotracers and nucleonic measurement systems for investigation of sediment transport

Abstract

The knowledge of sediment transport is of vital for a proper human intervention in river and coastal environment For instance, the use of rivers as waterways or for electricity generation, the construction, in coastal waters, of harbors and access channels with capital and maintenance dredging, the studyof beach erosion and nourishment, are activities for which this knowledge is mandatory. Radioactive tracers are particularly useful for the in situ measurement of sand movement close to the bottom (bed load), or of fine sediment and sludge transported in suspension. Over the past few years it has become clear that the synergistic modeling and tracer approach can make a significant contribution to addressing complex problems in natural systems, such as sediment transport in the aquatic environment. Tracer techniques are often employed to validate hydrodynamic models to enhance confidence in the predictive value of the models. Radioisotopes as sealed sources: gamma scattering and transmission gauges, are also used for sediment monitoring, being applied for measuring high concentration of sediment in suspension or for the measurement of bulk density of fine sediment deposited in reservoirs and harbors.