Caracterización geomorfológica y aplicación del índice hidrogeomorfológico (IHG) en el Alto Valle del Río Negro

Abstract

The study area covers the upper section of the Negro River (38 ° 59'44.42 "S, 67 ° 59'55.31" W) in the homonymous province, from the confluence of the Limay and Neuquén rivers to the town of Chichinales (39 ° 8'16.01 "S, 66 ° 47'31.05" W). The fluvial geomorphological characterization was carried out and the Hydrogeomorphological Index (IHG) was applied, which constitutes the first application of the same in a river with an arid climate in Argentina, in circumstances different from that of its creation and in this way to verify its effectiveness. The geomorphology of the Negro River presents river bars, floodplain, alluvial fans, river terraces, and a large number of meanders, riparian vegetation, which make up the river ecosystem. Given the control exercised by dams and reservoirs in the headwaters, they cause a decrease in flow, floods, and drafts are poor, consequently favouring the lack of fluvial dynamics in the area. The application of the IHG contributed to the knowledge of fluvial geomorphology. It evaluates its environmental ecological status, based on the assessment of three components, Functional Quality of the River System, Quality of the Channel, and Quality of the Banks. As a result, it was obtained that the Hydrogeomorphological quality of the Negro river is moderate, which indicates that it is necessary to maintain the focus on continuous river restoration and seek a balance between the advancement of society and the river's area.