Caracterização granulométrica dos depósitos alúvio-coluviais de microbacias do rio Copiapó – região de Atacama (Chile)

Granulometric characterization of the alluvial-colluvial deposits in microbasins of the Copiapó river – Atacama region (Chile)

Abstract

This study examines the granulometric characteristics of sediments within alluvial-colluvial deposits in Chile’s Copiapó River basin. By analyzing the detailed grain-size composition of these deposits, the research aims to enhance understanding of the dynamics behind debris flows in this region. Debris flows—massive landslide events often triggered by intense rainfall—are common in the arid landscapes of the Coastal and Andes Mountain ranges. These flows are dense mixtures of gravel, finer sediments, and water, with distinctive non-Newtonian, viscoplastic fluid behaviors, enabling them to transport large materials over significant distances. A key aspect in determining the rheological properties of these flows is granulometry, specifically the concentration of fine sediments, which directly impacts viscosity and flow resistance. This study provides essential granulometric data, deepening insights into how sediment composition influences flow behavior and offering a scientific foundation for future characterizations of sediment mobility within these debris flows. By contributing to a more nuanced understanding of sediment transport dynamics, this work has potential applications in predictive modeling and risk assessment for geological hazards in mountainous regions.

Keywords: Granulometric composition, Debris flows, Copiapó River basin.