Abstract

GIL, Verónica. Fluvial geomorphology of the El Negro stream basin, Buenos Aires, Argentina. Rev. Univ. geogr. [online]. 2011, vol.20, n.1, pp. 151-169. ISSN 1852-4265.

The aim of this work is to analyze fluvial geomorphology in the El Negro stream. The basin, with 206 km², is located in the South of Buenos Aires Province, Argentina. It is characterized by low frequency flash floods generated by heavy rainfall. These flash floods affect the people who live in Sierra de la Ventana village. Knowledge of fluvial dynamics is necessary in order to improve planning policies. Morphometric rates have been calculated and a hydrogeomorphological map of the basin has been developed. Rainfall and flow records have been analyzed in different periods. According to this, morphometric rates establish the flash flood dynamics of the basin. The hydrogeomorphological analysis highlights two major units with different hydrological characteristics. This affects infiltration and runoff processes in the basin. On the other hand, rainfall and flow analysis allowed to establish the interdependence of these two variables. Thus, flow distribution throughout the year reflects rainfall in the basin of El Negro stream.

Keywords : Fluvial geomorphology; Hydrogeomorphological map; Morphometry; Ventania System.