The use of particle tracking in sediment transport studies: a review

Abstract

AbstractNew European environmental legislation such as the Shellfish and Habitats Directives, together with the more recent Water Framework Directive, are driving new and fresh approaches to sediment management. Regional authorities, environment protection agencies and consultants are increasingly being required to adopt a holistic, system-wide appreciation of sediment flux in aquatic systems. Increasingly, and necessarily, there is a need to describe sediment (and contaminant) transport pathways on dynamically variable and spatially distributed scales rather than at single point localities. ‘Particle tracking’, or as it is also known ‘particle’ or ‘sediment tracing’, providing certain assumptions are satisfied, offers a practical methodology for the assessment of transport pathways of a variety of sediments across wider temporal and spatial scales, and is available for silts, sands, granules, pebbles and cobbles. Although not a new technique, particle tracking has experienced a resurgence of interest and application by geologists, hydrologists and oceanographers principally as a result of the arrival of new, innovative manufacturing and measurement technologies. These have overcome previous limitations presented by the method, and have also provided a foundation for silt tracking that previously did not exist. The purpose of this paper is to provide an overview of the particle tracking methodology in the modern context, with a bias towards the practicalities of conducting a tracking experiment. We present a detailed summary of the factors and considerations involved in conducting tracking studies, including an assessment of tolerance limits on synthetic tracers and the importance of appropriate sampling strategies. In addition, we highlight the principal technical limitations of the method. We summarise the historical background regarding the use of the particle tracking method outlining the dominance of studies on sand transport and the paucity of silt tracking studies, and draw attention to some of the potential areas of application of this innovative approach.