Abstract

The Copiapó river basin, to the south of the Atacama desert, has a strong anthropic intervention due to mining, agricultural and urban activities. The presence of mining environmental tailings in the basin is relevant, mainly when they are close to watercourses and populated areas. In this work the relationship between the variations of copper, lead, mercury and arsenic concentrations related to the sediment transport dynamics along a year was studied. From five points along the Copiapó river, including areas of mining, agricultural and urban intervention, the sediments were analyzed for granulometry and chemical composition. The results show that the temporal variation of elements concentrations was proportionally inverse to the transport of the finest fraction of the sediment. This is related to changes in sediments transport, influenced by sporadic rains, snow melting, sediment supply from upstream sediments and wind events in areas with mining activity.