Abstract

DEGIOVANNI, Susana; VILLEGAS, Mónica  and  ULLA, Juan P. Análisis de la carga de fondo y dinámica de trasporte en el Río cuarto, provincia de Cordoba, como base para una minería de aridos sustentable. Rev. Asoc. Geol. Argent. [online]. 2013, vol.70, n.2, pp.238-248. ISSN 0004-4822.

Like most streams in south of Córdoba Province, the Cuarto river shows changes in its operation (downcutting and lateral erosion in the middle basin) related to natural (climatic and tectonic) and anthropogenic causes (channel mining, rectifications, dam constructions). Some technical and administrative sectors assign to sand and gravel mining the destabilization of Cuarto river in its middle reach, but comprehensive studies are still required to consider the particularities of different sub-basins (morphological, hydrological, sedimentological) to analyze the impact of various activities, including mining. In order to contribute to the sustainable management of the river systems, this work intends to characterize the tractive load, defining their origin and analyzing rates and dynamics of transport. For this aim, geological and geomorphological features in the upper basin are set, hydrology of sub-basins Piedras Blancas, Las Canitas and La Invernada are analyzed, tractive load grain size is tipyfied, and direct and indirect methods for estimating transported volumes are applied. Conclusion are: psephitic sediments are predominantly provided by Piedras Blancas river and psammitic sediments by Las Canitas, La Invernada and Seco rivers. These contributions are related exclusively to summer floods; in low flow conditions Cuarto river mobilizes its riverbed sediments at 30-50 m3/day rate; sand and gravel mining locally powers the imbalance of sediment, so seasonal rates of replacement should be considered to reduce negative impacts and contribute to sustainability; regional downcutting is mainly related to climatic and tectonic causes and, subordinately, to anthropogenic causes.

Keywords : Provenance; Transport; Sand and gravel mining; Sustainability; Cuarto river.

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