Contribuições do modelo de regressão não-linear logarítmico aplicado à análise de perfis longitudinais em geomorfologia fluvial

Abstract

This paper deals with the investigation of the geometric behavior of longitudinal profiles and its recurrent association as an indicator of hydrodynamic conditions in fluvial geomorphology. In the literature it is recurrent the investigation of graded profile results in assuming a negative linear logarithmic curvature of concavity that attenuates in downstream direction. However, the simple morphological observation of the profile is not sufficient to indicate the conditions between erosion, deposition and distribution of energy in the system. In this context this paper presents the statistic method of non-linear logarithmic regression as an instrument to be evaluating quantitatively how much the longitudinal profile of a fluvial course approaches the ideal equilibrium profile, as well as to indicate possible conditioning factors that could influence its geometry. As a scenario, the main tributaries that drain part of the hydrographic divisor of the Velhas and Paraopeba river basins in Minas Gerais are used. In these tributaries the method is a suitable tool to evaluate the geometry of the longitudinal river profiles. The variability of the pedological cover is an indicator of the way the watercourse can dissects the surface.