Geomorphological analysis of the basin of the Jacaré-Pepira (SP)

Abstract

This study was conducted in the high and median portion of the Jacaré-Pepira basin. The study area is 1650 km2. The objectives of the study were to quantify the erosion process and to determine the best characteristic that could better differentiate erosion areas. The geomorphologic map of the area was obtained using aerial photograph. Relief units were identified by RADAMBRAS11L methodology. In general, the area is characterized by a sequence of lithostructure plateaus developed over sedimentary and basic rocks in a sub-horizontal structure. The contact among the plateaus is through topographic ruptures. Geomorphologic units were individualized as high, median and low plateaus, considering the positive and negative slope of the regional expression. These units correspond to areas better conserved, where the relief forms are light or strongly undulated. In the high geomorphologic units was observed the highest slops and the highest preserved areas. They are composed by fluvial dissections. The convexity and interfluvial length are of 250 to 1500 m. The predominant cover on the high plateaus is a sand material from Itaqueri form ation. The medium plateaus were defined as intrusions on the slope of the high plateaus. They occur in larger areas and the relief form is almost flat with convex edge. Basic rocks, from the Serra Geral formation and a sand material from The Piramboia and Botucatu formations compose the rocks under these units. The low plateau presented light relief with a convex to rectilinear-concave slope. The predominant material under these plateaus is a sand material from the Botucatu formation

Keywords

• Jacaré-Pepira basin
• geomorpholig analysis
• erosion process