Using Geochemical Fingerprints for Assessing Sediment Source Apportionment in an Agricultural Catchment in Central Argentina

GARCIAS, YANINA; TORRES ASTORGA, ROMINA; OJEDA, GUILLERMO; DE LOS SANTOS VILLALOBOS, SERGIO; TEJEDA, SAMUEL; VELASCO, HUGO

Water

MDPI-Chris Bradley

Lugar: Basel; Año: 2021 vol. 13

Abstract: In the hilly semi-arid region of central Argentina, where the agricultural frontier expands atthe expense of natural ecosystems, soil erosion is one of the most alarming environmental problems.Thus, obtaining knowledge about the dynamics of erosive processes and identifying erosion hotspotsconstitutes a primary scientific objective. This investigation is focused on estimating the apportionmentsof main sources of sediments, at the mouth of a small catchment called Durazno del Medio,located in the province of San Luis, Argentina. Elemental Analysis, measured by Energy DispersiveX-ray Fluorescence (EDXRF), was used to select potential geochemical fingerprints of sediment. Theunmixing model MixSIAR was applied to approximate the contribution of each identified source inthe sediment accumulation areas at the mouth of the catchment. Potential sediment sources wereselected using two criteria: (i) a hierarchical approach to identify the main geomorphological units(GUs) and (ii) the main land uses (LU), recognized by examining satellite images and field recognitions.The selected geochemical tracers were able to distinguish sources located in the Crystallinebasement hills with loess-patched (CBH) as the main sediment contributors.