Análise de características morfométricas e compartimentação geomorfológica de bacias hidrográficas da margem esquerda do Rio São Francisco - Norte de Minas Gerais

Abstract

This work analyses the morphometric characteristics of some drainage basins located at the left bank of the São Francisco River in order to contribute to the understanding of its environmental dynamics within the Water Resources Planning Unit SF09 in the northern region of Minas Gerais. The drainage basins of the study area present dense concentration of “veredas” which are important ecosystems for the maintenance of environmental quality not only of the São Francisco River as a fluvial system, but also for the Cerrado biome. The study of the drainage systems show differences in their hydrologic behavior due to numerous factors involved in the landscape dissection processes, resulting in the development of different types of relief forms, hydro geomorphologic and soil contexts which lead to the occurrence or absence of “veredas”. Therefore, it is of great importance to get a better understanding of the processes and forms associated with the action of water as templating agent acting at the earth's surface. Aspects such as altitude, slope, length of slopes and river channels, forms and guidelines of the tops, slopes and valleys are linked to water flow patterns on the surface, exerting great influence on the occurrence of “veredas”. In order to better understand these aspects morphometric indices for the basins were also generated and field campaigns conducted. Data analysis allowed the compartmentation of the relief into 4 large geomorphologic units with distinct environmental dynamics. These units are in different stages of evolution, in which dissection is marked by differentiation in river incision and the consequent reflex in the relief denudation, as well as by the diversification of the characteristics of the water bodies. The analysis of the relief compartmentation contributes to the understanding of the spacialization of the environmental dynamics of the region and contributes as support for future work associated with the preservation of “veredas” in the context of the preservation of these water bodies which are major tributaries of the São Francisco River and therefore fundamental to the regional economy.