Morphometric parameters of the relief and drainage network of a tropical subbasin

Abstract

This research analyzed the morphological/morphometric parameters of the relief and drainage network of the Formiga River subbasin, southern Minas Gerais State, Brazil. This study identified and examined the influences of control mechanisms in the development of current configurations. The methodology was based on the application of indices and parameters: (1) slope length (Hack's Sl); (2) normalized slope index (ksn); (3) river hierarchy; (4) drainage density; (5) hydrographic density; (6) sinuosity index; (7) density of structural lineaments; (8) transverse topographic symmetry factor; (9) asymmetry factor of drainage basins; (10) topographic profiles transverse to the valleys; (11) relief ratio; (12) roughness index; (13) roughness concentration index; (14) compactness coefficient; (15) circularity index and (16) form factor. The results indicated 3 sectors of the subbasin with distinct geomorphic behaviors, which resulted in peculiar surface structures and divergent current dynamics. The subbasin presents physical evidence that demonstrates and corroborates strong tectonic and structural control in the development of the current drainage network and relief. Human action has also affected, from the construction of dams, the dynamics of the lower course of the river, drowned by the reservoir of the hydroelectric plant of Furnas.