Levantamento de taxons geomorfológicos através de sensoriamento remoto e SIG: região centro norte do Escudo Sul-rio-grandense

Abstract

The present work describes a survey of geomorphological taxa carried out in Folha de Caçapava do Sul - RS State, Brazil, through geotechnology involving digital elevation models, satellite images and Geographic Information System. Having as main objective, to identify, to analyze and to classify the geomorphological forms reaching the 4th taxonomic level (scale 1: 100.000). Through various analyzes, mainly geological and morphometric using geoprocessing techniques, seven morphological sculptures were identified and described: Residual Sedimentary Plateau, Lower Sedimentary Plateau, Residual Plateau, Low Crystalline Plateau, Serra de Santana, Alluvial-colluvial, Plains and Depression Arroio Moirão. They were grouped into four geomorphological domains, they are; Sul-RioGrandense Shield, Camaquã Basin, Paraná Basin and Sedimentary Deposit. In each morpho sculpture, the modeled ones were mapped and their characteristics discussed. The region has a gently to heavily undulating surface with elevations ranging from 67 to 481 meters, with only 20% of the area having an altitude of more than 275 meters. The relief aspect comprises models of dissection and accumulation, the first corresponding to more than 80% of the entire area. Both developed on rocks from Paleoproteorozoic to Triassic ages. The geological diversity of the area is revealed through the landscape heavily worked by erosive agents, forming a wide worn area composed of hills and hills with different types of dissection patterns, mainly the homogeneous type with predominantly convex tops. About 80% of the dissected area is represented by high dissection rates ranging from 33 to 54 with a predominance of the 44 index followed by 33, which characterizes medium to strong notching of the valleys and an average to high drainage density.