Applicability of Fingerprinting for Identification of Sediment Sources in a Mesoscale Semiarid Catchment

Abstract

The study aimed at identifying sediment sources in a mesoscale catchment (933 km²) located in the Brazilian semiarid region. The research explored the potential of using a fingerprinting technique to verify the origin of eroded sediments in a catchment by comparing physical and mineralogical properties of potential sediment sources and sediments deposited in a pond (6 x 10 3 m³ storage capacity) and a reservoir (20 x 10 6 m³ storage capacity). The goal was to assess the feasibility of using such material to identify sediment sources in a semiarid environment with a high density of surface reservoirs. Chemical variables were studied by mineralogical analysis using scanning electron microscopy (SEM) and multivariate statistics. The results showed that the fingerprinting technique is a potential tool to identify sediment sources comparing the properties of soils with silted material in reservoirs, allowing its use even in regions with low frequency of runoff.

The role of unpaved roads in the sediment budget of a semiarid mesoscale catchment

“…This shortcoming results from the insufficient knowledge about the sediment transport process in such structures, and the difficulty in obtaining monitored data to test the degree of connectivity between the road infrastructure, as a source of sediment, and the stream network. We faced this difficulty in our study, as well: the study area presents a dense network of surface water reservoirs and strong temporal variation of sediment transport, leading to the complexity of sediment transfer throughout the catchment (Mamede et al, 2018; Medeiros et al, 2010; Silva et al, 2018) and hampering a comparison of sediment yield. However, the results of this study contribute to better understand how small‐scale hydrological and sedimentological processes affect erosion rates and sediment yield on unpaved roads, as well as to quantify the impact of road infrastructure as an anthropogenic driver of the sediment budget in rural catchments.…”

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

“…Dams The average contributions of the upper catchment (SS = 23%; BS = 33%) were two-three fold greater than those estimated for the middle catchment (SS = 8%; BS = 10%). Typically, sources collected at larger distances from target sediment collection points have lower contributions because of the longer travel pathways and times (Le gall et al, 2017;Silva et al, 2018a;Batista et al, 2019). Such effects are likely pronounced in our study basin due to the following reasons: 1) the presence of small dams; 2) the longer transport times in semiarid compared with humid environments, and; 3) the flattened shape of the basin.…”

“…Although this approach has been successfully used in other Brazilian rivers in the subtropics (Minella et al, 2007;Tiecher et al, 2014;Ramon et al, 2020), its application for sediment source apportionment in a Brazilian semiarid ephemeral river system has not been reported yet, representing a significant research gap (Silva et al, 2018a;Collins et al, 2020).…”

Reservoir sediment characterisation by diffuse reflectance spectroscopy in a semiarid region to support sediment reuse for soil fertilization

“…This result shows the role of spatial scale in estimating sediment attributes: sediment generated in larger areas tends to present higher heterogeneity (Silva et al 2018), hampering its characterization from VNIR-SWIR spectroscopy and reducing the performance of prediction models. This finding suggests that homogeneous areas be established, for which the models could be transferred from one reservoir to another without (re)calibration requiring physicochemical laboratory data.…”