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

Abstract

New 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.

Dynamic interactions between cohesive sediment tracers and natural mud

“…For cohesive sediments, this means that the tracer must form flocs that have the same physical and dynamic properties as natural cohesive sediment and, therefore, must be incorporated into and transported via flocs (Black et al 2007). The transport and fate of cohesive sediment in aquatic environments is largely controlled by its settling velocity and MSF, which are in turn controlled by particle size, shape, effective density and porosity (Williams et al 2008).…”

Dynamic interactions between cohesive sediment tracers and natural mud

“…For cohesive sediments, this means that the tracer must form flocs that have the same physical and dynamic properties as natural cohesive sediment and, therefore, must be incorporated into and transported via flocs (Black et al 2007). The transport and fate of cohesive sediment in aquatic environments is largely controlled by its settling velocity and MSF, which are in turn controlled by particle size, shape, effective density and porosity (Williams et al 2008).…”

Coastal aeolian sediment transport in an active bed surface layer: Tracer study and conceptual model

“…The number of colored pixels of each color in one image was then normalized by dividing it by the total amount of colored pixels in that image. This method for analyzing the samples was chosen to overcome the tedious and time‐consuming part of most historical tracer studies that visually counted the number of tracer grains in a sample, which also might be subject to human error (Black et al 2007…”

Sediment Connectivity: A Framework for Analyzing Coastal Sediment Transport Pathways

“…Sediment tracer studies (both artificial, Black et al., 2007; Bosnic et al., 2017; Elias et al., 2011, and natural, Hein et al., 2013; McGann et al., 2013; Reimann et al., 2015; Rosenbauer et al., 2013; Wong et al., 2013) offer a Lagrangian technique for identifying pathways but are challenging to execute and recover (Elias et al., 2011). Grain trend analysis (Duc et al., 2016; Gao & Collins, 1991; Le Roux & Rojas, 2007; McLaren, 2013; McLaren & Bowles, 1985; McLaren et al., 1998; Poizot et al., 2006, 2008; Velegrakis et al., 2007) and analysis of bedform asymmetry (Barnard, Erikson, et al, 2013; Bartholdy et al., 2002; Sha, 1989; Velegrakis et al., 2007) offer additional techniques for identifying sediment pathways.…”

Dynamic interactions between cohesive sediment tracers and natural mud

“…For cohesive sediments, this means that the tracer must form flocs that have the same physical and dynamic properties as natural cohesive sediment and, therefore, must be incorporated into and transported via flocs (Black et al 2007). The transport and fate of cohesive sediment in aquatic environments is largely controlled by its settling velocity and MSF, which are in turn controlled by particle size, shape, effective density and porosity (Williams et al 2008).…”

Coastal aeolian sediment transport in an active bed surface layer: Tracer study and conceptual model

“…The number of colored pixels of each color in one image was then normalized by dividing it by the total amount of colored pixels in that image. This method for analyzing the samples was chosen to overcome the tedious and time‐consuming part of most historical tracer studies that visually counted the number of tracer grains in a sample, which also might be subject to human error (Black et al 2007…”

Sediment Connectivity: A Framework for Analyzing Coastal Sediment Transport Pathways

“…Sediment tracer studies (both artificial, Black et al., 2007; Bosnic et al., 2017; Elias et al., 2011, and natural, Hein et al., 2013; McGann et al., 2013; Reimann et al., 2015; Rosenbauer et al., 2013; Wong et al., 2013) offer a Lagrangian technique for identifying pathways but are challenging to execute and recover (Elias et al., 2011). Grain trend analysis (Duc et al., 2016; Gao & Collins, 1991; Le Roux & Rojas, 2007; McLaren, 2013; McLaren & Bowles, 1985; McLaren et al., 1998; Poizot et al., 2006, 2008; Velegrakis et al., 2007) and analysis of bedform asymmetry (Barnard, Erikson, et al, 2013; Bartholdy et al., 2002; Sha, 1989; Velegrakis et al., 2007) offer additional techniques for identifying sediment pathways.…”

Dynamic interactions between cohesive sediment tracers and natural mud

“…For cohesive sediments, this means that the tracer must form flocs that have the same physical and dynamic properties as natural cohesive sediment and, therefore, must be incorporated into and transported via flocs (Black et al 2007). The transport and fate of cohesive sediment in aquatic environments is largely controlled by its settling velocity and MSF, which are in turn controlled by particle size, shape, effective density and porosity (Williams et al 2008).…”

Coastal aeolian sediment transport in an active bed surface layer: Tracer study and conceptual model

“…The number of colored pixels of each color in one image was then normalized by dividing it by the total amount of colored pixels in that image. This method for analyzing the samples was chosen to overcome the tedious and time‐consuming part of most historical tracer studies that visually counted the number of tracer grains in a sample, which also might be subject to human error (Black et al 2007…”

Sediment Connectivity: A Framework for Analyzing Coastal Sediment Transport Pathways

“…Sediment tracer studies (both artificial, Black et al., 2007; Bosnic et al., 2017; Elias et al., 2011, and natural, Hein et al., 2013; McGann et al., 2013; Reimann et al., 2015; Rosenbauer et al., 2013; Wong et al., 2013) offer a Lagrangian technique for identifying pathways but are challenging to execute and recover (Elias et al., 2011). Grain trend analysis (Duc et al., 2016; Gao & Collins, 1991; Le Roux & Rojas, 2007; McLaren, 2013; McLaren & Bowles, 1985; McLaren et al., 1998; Poizot et al., 2006, 2008; Velegrakis et al., 2007) and analysis of bedform asymmetry (Barnard, Erikson, et al, 2013; Bartholdy et al., 2002; Sha, 1989; Velegrakis et al., 2007) offer additional techniques for identifying sediment pathways.…”