Abstract

BUSNELLI, José  and  HORTA, Luis R. Morfometría de cuencas montanas y metamorfosis fluvial, Tucumán. Rev. Asoc. Geol. Argent. [online]. 2014, vol.71, n.1, pp.11-20. ISSN 0004-4822.

Fluvial basins located on eastern slopes of the Northwestern Argentina are dominated by intense water discharges in short period of time during storm events of the summer pluvial period. The strong nick point in the transition zone of foothill-slopes, the powerful orographic rainfalls and the intense human pressure on the Tucumán foothill and apical plain conditioned the high flash flood risk due to alluvial and migratory processes due to avulsion of fluvial channels. In the current research the fluvial metamorphosis, measured as changes in sinuosity, was related to morphometric measures of the contributing areas of the basins: slope gradients, elongation, drainage density and torrenciality. The shape factors and quantitative parameters of the basins were determined through satellite image visualization on Geographic Information Systems (GIS). Trace changes on the alluvial drainage network through time was developed by photointerpretation of aereal photos of the year 2000 and visualization of Cbers satellite images of the year 2008. Concluding, torrentiality decreases from Gastona, Medinas-Chico, Seco y Balderrama basins, while metamorphosis from higher to lower is: Seco, Gastona, Medinas-Chico, Balderrama. So, the relationship is kept for all the basins, unless Seco river, which could be explained by its lower elevation and higher pluvial discharges.

Keywords : Alluvial flash flood; Sinuosity; Geographic Information System (GIS); Montane basins Tucumán.

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