Cartografia geomorfológica aplicada em áreas com cava de mineração no Alto Paranaíba (MG)

Abstract

The Alto Paranaíba region has a history of economic activity linked to mining, which results in anthropogenic action on the physical environment, altering the landforms. Geomorphological mapping is an instrument for environmental planning and for analyzing the current conditions and evolution of the relief. The aim of this research was to analyze the geomorphological characteristics of areas with mining pits in Alto Paranaíba (MG), as well as to assess anthropogenic interference using geomorphological mapping. From a theoreticalmethodological point of view, the research was based on the anthropogeomorphological approach, making use of retrospective geomorphological cartography applied to mining areas. Its methodology was subdivided into two phases. The first involved morphometric and morphological mapping (1:25,000) in areas around four (4) pits in order to recognize the geomorphological compartments. Two clay pits were selected in the municipality of Coromandel, one sand pit in Estrela do Sul and one diamond pit in Romaria. The second phase was aimed at organizing detailed geomorphological mapping (1:10,000) in different scenarios (2011 and 2021) for the sand and diamond pits, using anaglyphs. These two pits were selected on the basis of the geomorphological characteristics revealed in the first phase, as well as the intensity of anthropogenic alterations. The results show 24 mappings involving cartographic bases, morphometric (hypsometry and slope) and morphological (slope orientation, horizontal curvature and vertical curvature) maps, which helped identify the geomorphological compartments in which the four sample areas are located. The sand pit is located on a steep plateau front, where the first-order channels of the left bank of the Bagagem River are located; the diamond pit is also located on a steep plateau front, but where first-order channels such as the Água Suja, a tributary of the right bank of the Bagagem River, originate; the Taguá clay pit is located on the edge of residual reliefs with tabular tops, from where the first-order channels of the Douradinho River originate, and; the Várzea clay pit was installed on the plain and river terraces of the Santo Inácio River, already in its lower basin. The results of the second phase of the research are also presented, which involves organizing detailed geomorphological mapping for the sand and dyke pits in the 2011 and 2021 scenarios. The comparison between these years reveals significant changes in the terrain, highlighting both natural processes and human interventions. The work focused on the technical application of retrospective geomorphological mapping using anaglyphs, as well as the representation of original and anthropogenic features using symbologies. This technique can be replicated in future work, both for the Tágua and Várzea caves and for other caves. The maps generated in Phases 1 and 2 can contribute to planning the environmental recovery of the cave areas, as well as being a model for the identification of geomorphological compartments to help recognize future areas with economic potential.