Selecting Color-based Tracers and Classifying Sediment Sources in the Assessment of Sediment Dynamics Using Sediment Source Fingerprinting

Abstract

The use of sediment color as a fingerprint property to determine sediment sources is an emerging technique that can provide a rapid and inexpensive means of investigating sediment sources. The present study aims to test the feasibility of color fingerprint properties to apportion sediment sources within the South Tobacco Creek Watershed (74 km 2 ) in Manitoba, Canada. Suspended sediment from 2009 to 2011 at six monitoring stations and potential source samples along the main stem of the creek were collected. Reflectance spectra of sediments and source materials were quantified using a diffuse reflectance spectrometry, and 16 color coefficients were derived from several color space models. Canonical discriminant analysis was used to reclassify and downsize sediment source groups. After the linear additive test and stepwise discriminant function analysis, four color coefficients were chosen to fit the Stable Isotope Analysis in R model. Consistent with the conventional fingerprinting approach, the color fingerprint results demonstrated a switch in the dominant sediment source between the headwaters and the outlet of the watershed, with the main sources being topsoil in the upper reaches, whereas outcrop shale and stream bank materials dominated in the lower reaches. The color fingerprinting approach can be integrated with conventional fingerprints (e.g., geochemical and fallout radionuclide properties) to improve source discrimination, which is a key component for source ascription modeling. We concluded that the use of color fingerprints is a promising, cost-effective technique for sediment source fingerprinting.

Determining sources of fine-grained sediment for a reach of the Lower Little Bow River, Alberta, using a colour-based sediment fingerprinting approach

“…Furthermore, within a watershed, Carter et al (2003) reported a spatial difference in primary sediment sources between the upper and lower reaches due to land use difference, for the River Aire watershed, UK. Similarly, Koiter et al (2013a) and Barthod et al (2015) reported a shift of the dominant sediment source along the stream within the South Tobacco Creek watershed, MB, Canada, as a result of a dramatic change in the topography and due to variations in the connectivity between hillslopes and the stream channel. Thus, there is considerable variation in the dominant sediment sources both within and between watersheds, which means that site-specific assessment is often required to underpin meaningful management advice.…”

“…Previous studies (Koiter et al 2013a;Barthod et al 2015) at the South Tobacco Creek watershed, MB, Canada, demonstrated that soil colour-based fingerprints predicted similar source apportionment as fallout radionuclides (i.e., 137 Cs) and geochemical properties. Recently, the fingerprinting technique using colour-based tracers has proved to be a cost-effective alternative in estimating source contributions to suspended sediments in a range of environments (Martinez-Carreras et al 2010;Brosinsky et al 2014;Barthod et al 2015).…”

“…Sediment fingerprinting techniques have been increasingly used to discriminate and apportion sediment sources in a watershed (Collins et al 2012;Koiter et al 2013a;Walling 2013;Barthod et al 2015;Collins et al 2017). Ideally, a fingerprint property is characterized by conservative behaviour, but selectivity and changing environmental conditions through a watershed might alter sediment fingerprints (Koiter et al 2013b).…”

“…The conventional sediment fingerprinting technique employs a range of properties such as geochemical elements and fallout radionuclides as tracers (Walling 2013), and has been used widely for obtaining sediment source information (Carter et al 2003;Collins et al 2013;Koiter et al 2013a;Stewart et al 2015). Previous studies (Koiter et al 2013a;Barthod et al 2015) at the South Tobacco Creek watershed, MB, Canada, demonstrated that soil colour-based fingerprints predicted similar source apportionment as fallout radionuclides (i.e., 137 Cs) and geochemical properties. Recently, the fingerprinting technique using colour-based tracers has proved to be a cost-effective alternative in estimating source contributions to suspended sediments in a range of environments (Martinez-Carreras et al 2010;Brosinsky et al 2014;Barthod et al 2015).…”

“…Defining sources and selecting suitable tracers are important for reducing uncertainty in sediment source apportionment (Barthod et al 2015;. If the tracers cannot be distinguished among sources, uncertainty associated with the relative contributions of sources to sediment is likely to increase (Stewart et al 2015).…”