Relação entre o escoamento de base e os diferentes sistemas hidrogeológicos do Estado de Minas Gerais

Abstract

The estimation of surface flow into direct surface flow and base flow is fundamental for understanding the hydrologic behavior of basins, being possible, among other features, the capability of discharges maintenance during the dry seasons. Analysis of the related base flow with hydrogeological classes can contribute to understand the hydrological processes involved. This work aimed to estimate the base flow for eight fluviometric stations that were chosen according to the hydro geologic systems observed in the State of Minas Gerais. A numerical filter was employed in order to evaluate the relationship between hydrogeology and water flow regime. Daily discharge data sets, between October/1981 and September/1991, were used in the study. In all cases, the base flow accounted for over 50% of the water flow in rivers. The hydrogeological systems "xistosa", "pelítica" and "cobertura detrítica" presented smaller amount of base flow in the rivers discharge than other hydrogeological systems and obtained the same statistical classification. Based on the results we concluded that hydrogeology exerts indirect influence on the relationship between the base flow and river discharge.