Determining sources and transit times of suspended sediment in the Murrumbidgee River, New South Wales, Australia, using fallout ¹³⁷Cs and ²¹⁰Pb

Abstract

Abstract. Sediment budgets typically require an estimate of the proportional yield from erosion sources to sediments in transport and storage. This becomes increasingly difficult as catchments become larger, and erosion, storage, and deposition processes become more complex. We demonstrate how fallout radionuclides can be used to estimate the proportional contributions to sediment load, from a tripartite classification of erosion sources in a large catchment (the mid-Murrumbidgee, 13,500 km2). The three major IntroductionSediment budgets typically require estimates of (1) basinwide sediment yield, (2) erosion rates from upland, channel, and floodplain sources, and (3) changes to the volume and residence time of material in downslope storages [Trimble, 1983] tribution to sediments from various erosion sources, to be measured directly, rather than inferred by manipulation of erosion rate and sediment yield terms. The residence time of this material in channels can also potentially be estimated. In this paper we present a method for using fallout tracers to deconvolve the proportionate contributions to suspended sediment from various erosion sources in a large catchment (13,500 kn12). We also provide some constraints for the residence time of suspended fine-grained material within it, and combine this information with the known annual sediment yield and surface areas of the erosion sources, to estimate the changes in specific yield from these sources over a 10-year period. Study AreaThe Murrumbidgee River drains one of Australia's largest

An investigation on suspended solids sources in urban stormwater runoff using 7Be and 210 Pb as tracers

“…A discrimination of sediment sources can be achieved from mass balancing tracers (Wallbrink et al 1998). …”

Temporal variations of sediment source from a reservoir catchment in the black soil region, Northeast China

“…Therefore, the sediment sources were broadly divided into three categories: cultivated lands, uncultivated lands and subsoil material from gully/channel banks. Radioactivities of the accumulated sediment from the three sediment sources are anticipated to be different, and a simple model that has been successfully used in literatures (e.g., Wallbrink et al, 1998;Zhang et al, 2004) was employed to determine the relative contributions of the three potential sediment sources to the sediment deposit.…”

“…Thus, interest in sediment source identified by fingerprinting properties has increased in recent decades, and more and more work on sediment sources have been conducted in many regions over the world, such as in the UK (Gruszowski et al, 2003), the USA (Wallbrink et al, 1998;Lamba et al, 2015), Brazil (Franz et al, 2014), Tunisia (Slimane et al, 2013), Korea (Kim et al, 2013) and Chinese Loess Plateau (Zhang et al, 1989;Yang and Xu, 2010) and Southwestern region (Zhang et al, 2004). However, seldom study on this issue has been conducted in the black soil region of Northeastern China, where soil has been experiencing severe erosion, resulting from the easy erodibility of black soil, harsh climatic conditions and extensive human activity.…”

“…Different types of fingerprinting properties such as metals (e.g., Blake et al, 2012), stable isotopes (e.g., McKinley et al, 2013), mineral magnetic properties (Walling et al, 1999) and fallout radionuclides (e.g., Huisman et al, 2013) have been used, among which fallout radionuclides 137 Cs and 210 Pb ex are commonly used in a variety of geomorphic settings (e.g., Peart and Walling, 1986;Wallbrink et al, 1998;Gruszowski et al, 2003).…”

Ascribing soil erosion types for sediment yield using composite fingerprinting technique

“…To accomplish this, research has traditionally used single component signatures encompassing mineralogy (Klages andHsieh 1975, Wood 1978), colour (Grimshaw andLewin 1980, Carreras et al 2010), mineral magnetic (Bonnet et al 1989, Walden et al 1997, Hatfield and Maher 2009, Wang et al 2011, fallout radionuclides (Loughran et al 1992, Walling and Woodward 1992, Olley et al 1993, Wallbrink et al 1998, Zapata 2003, Mabit et al 2008, Shi et al 2011, Yan et al 2012, Benmansour et al 2013) and organic matter (Santiago et al 1992) properties. However, using single property or component signatures is likely to prove unrealistic and result in spurious linkages between source materials and sediment (Collins and Walling 2002), so most fingerprinting studies now employ composite fingerprints, which comprise a range of different diagnostic properties influenced by contrasting environmental controls, and thereby greatly improve the reliability of sediment source discrimination (Walling et al 2006).…”