Tributary contributions to sediment deposited in the Jacuí Delta, Southern Brazil

Using particle size distributions to fingerprint suspended sediment sources—Evaluation at laboratory and catchment scales

“…The independent validation of sediment source fingerprinting estimates has been rarely undertaken (e.g., Batista et al, 2022; Gaspar et al, 2019). To validate estimated source proportions using PSDs as a fingerprint herein, we used sediment budget estimates generated using conventional water sampling; this has, to date, been used in few sediment fingerprinting studies (e.g., Collins et al, 1998; Dabrin et al, 2021; Tiecher et al, 2022), mainly due to the extra costs associated with the installation of equipment and sampling (Collins et al, 2020, 2017; Collins & Walling, 2004).…”

Combining sediment source tracing techniques with traditional monitoring: The “Arvorezinha catchment” experience

“…The authors reported that combining different environmental diagnosis techniques effectively outlined the fragility of those areas where overland flow may accumulate and lead to accelerated soil degradation processes. Moreover, Tiecher et al (2022) have also demonstrated that using sediment source tracing techniques, combined with sediment flux monitoring, can improve our understanding of the sediment source contributions to one of the largest lakes in South America: the Guaíba Lake (482 km 2 ). They used publicly available data from long‐term monitoring of river discharge and SSC (1978–2019) combined with the shorter‐term monitoring of chemical element concentrations in bed sediment (2000–2011) as geochemical tracers.…”

“…More recently, the target catchment area jumped to 5942 km 2 in a catchment experiencing a widespread land‐use change in the last years (Ramon et al, 2020), where the conversion of natural grasslands into cropland accelerated soil erosion and sediment delivery to the river systems. In addition, two more tentative approaches have used the sediment collected in the tributary outlet as potential sources to estimate the contribution of sediment from these tributary catchments to that supplied to a larger drainage system, such as the Uruguay River (266 132 km 2 ) (Ramon, 2021) and the Guaíba Lake (85 139 km 2 ) (Tiecher et al, 2022).…”

“…The sediment source research in the Arvorezinha catchment allowed studies to be applied to larger catchment sizes at different locations across Brazil and zones characterized by source types of increasing complexity. Studies that initially focused on two to three potential sources and mainly focused on land uses have turned into studies with four to five potential sources with different sediment sampling strategies (Tiecher et al, 2018), contrasted particle sizes (Amorim et al, 2021; Rodrigues et al, 2018), different mathematical models (Batista et al, 2019), stable isotope and radionuclide tracers (le Gall et al, 2017; Ramon, 2021; Valente et al, 2020), potential sources of sediment based on the soil type (le Gall et al, 2017), catchment sub‐region (Batista et al, 2019) and tributaries (Tiecher et al, 2022). Despite the advances, the lack of research in urban (Franz et al, 2014; Poleto et al, 2009), forest (Rodrigues et al, 2018; Valente et al, 2020) and natural grassland catchments is still notable (Ramon, 2021).…”