Influencia de la litología en la variación de los parámetros morfométricos, sistema de ventania, Argentina

Abstract

The area dealing with this study is located at the South of the Ventania system, in the Southwestern of Buenos Aires province, Argentina. The sub-basins of Oro´s creek, Ventana, Sauce Corto and Pantanoso drain off opposite hillside. The fl uvial dynamics of this sub-basins is generated by the inter-relationships of hydrometeorological, geological and geomorphological factors. The morphometric indexes refl ect the interactions between these factors. Therefore, the aim of this paper is to analyze morphometric indexes to determinate the influence of lithology, structure and morphology of river dynamics in 4 sub-basins mountain environment. For each sub-basin, the Bifurcation ratio (Rb), Drainage Density (Dd), Torrencial Index and Storage Coeffi cient have been analyzed and compared. The Rb between successive orders was more representative to identify lithologic variations and changes in river dynamics. The analysis of mean Rb, length ratio and elongation ratio allowed to take conclusions about the behaviour of hydrological basins. The type of outcrop rock, its areal distribution and the slope of each basin have infl uence upon Drainage Density value.