Applying geochemical and colour properties to quantify sediment sources in a Brazilian semiarid ephemeral river system

A - Papers appearing in refereed journals

Nascimento, R. C., Maia, A. J., Bezerra da Silva, Y .J. A., Amorim, F. F., Araujo do Nascimento, W. C., Tiecher, T., Evrard, O., Collins, A. L., Biondi, C. M. and Bezerra da Silva, Y .J. A. 2022. Applying geochemical and colour properties to quantify sediment sources in a Brazilian semiarid ephemeral river system. Journal of Hydrology. 613 (A), p. 128360. https://doi.org/10.1016/j.jhydrol.2022.128360

AuthorsNascimento, R. C., Maia, A. J., Bezerra da Silva, Y .J. A., Amorim, F. F., Araujo do Nascimento, W. C., Tiecher, T., Evrard, O., Collins, A. L., Biondi, C. M. and Bezerra da Silva, Y .J. A.
Abstract

The Brazilian semiarid is the most densely populated dry region in the world. Although climate change projections underline the need for the creation of integrated strategies to protect water resources in the semiarid, sediment source apportionment data remain scant for this environment. Accordingly, we evaluated sediment source contributions in one of the most relevant Brazilian semiarid catchments by combining geochemical and colour tracer properties. In doing so, we explored the applicability of colour tracers as a low-cost alternative to the use of time-consuming and costly properties, such as geochemical tracers. Two source classification schemes were used based on environmentally contrasting regions within the catchment (upper, middle and lower catchment parts) and land use (Caatinga biome - natural vegetation, unpaved roads, and channel banks). Suspended sediments (SS) and bed sediments (BS) were used as target sediment. A total of 660 individual source material samples were collected and composited. Geochemical and colour tracers were measured on the source and target sediment samples and used as potential fingerprints to discriminate and quantify the sediment source contributions. The geochemical tracers provided weak source discrimination based on land use. However, combining geochemical and colour tracers improved the final outputs. Using the MixSIAR model, the lower catchment contributed more sediment than the other regional sources. The Caatinga (SS = 49 %; BS = 47 %) contributed more sediment than channel banks (SS = 35 %; BS = 39 %). Overall, our results suggest that the recovery and conservation of the Caatinga vegetation and the stabilization of channel banks, especially in the lower catchment part, are critical for improving sediment supply control in the semiarid study basin. More studies are needed to evaluate the conservative behaviour of colour tracers in ephemeral rivers.

KeywordsDrylands; Sediment fingerprinting; Colour tracers; Soil erosion; Climate change; Sediment transport
Year of Publication2022
JournalJournal of Hydrology
Journal citation613 (A), p. 128360
Digital Object Identifier (DOI)https://doi.org/10.1016/j.jhydrol.2022.128360
Web address (URL)https://doi.org/10.1016/j.jhydrol.2022.128360
Open accessPublished as non-open access
FunderNational Council and Technological Development (CNPq)
Biotechnology and Biological Sciences Research Council
Funder project or coderesearch productivity scholarship (Process Number: 303221/2019-4)
S2N - Soil to Nutrition - Work package 3 (WP3) - Sustainable intensification - optimisation at multiple scales
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES)
Output statusPublished
Publication dates
PrintOct 2022
Online23 Aug 2022
Publication process dates
Accepted13 Aug 2022
PublisherElsevier Science Bv
ISSN0022-1694

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