Mapeamento de fragilidade ambiental do Parque Nacional dos Campos Ferruginosos, Carajás-PA

Abstract

This research is focused on Physical Geography, and brings an integrated environmental analysis of the landscape. The general objective is to understand the morphodynamics of the Campos Ferruginosos National Park landscape through the mapping of environmental fragility, through the crossing of geoenvironmental data (soil, vegetation and relief). This research is based on conceptual bases of renowned authors and important contributions such as Sotchava (1977); Bertrand (1971); Ab'Saber (1969); Vidal (2014); Cristofoletti (1999); Tricart (1965), and Ross (1992, 1994 and 2008), which is the main methodological reference. The manipulation of geotechnologies allowed the data processing and elaboration of the cartographic bases, carried out on a scale of 1: 250,000, using the software Qgis 2.18. From the thematic maps of slope, pedology, NDVI and land use and occupation were individually inserted a text file in Qgis through the algorithm “r.reclass” whose purpose was to create new scratch files containing a new numerical classification containing the values or weights indicating hierarchically the degree of environmental fragility of each of the thematic map classes, which were: very high (5), high (4), medium (3), low (2) and very low (1). After creating the new rasters containing the cited information, the information was crossed using the Qgis raster calculator, with the following equation: NDVI + soils + slope + use and occupation = frailty map, which was reclassified into 3 frailty classes, stable, moderate and unstable. The results showed that the Ferruginous Fields PARNA has areas with erosive potential and areas of unstable fragility, in which geomorphology played a very significant role, which facilitated the interpretation of the dynamic operation of the ferruginous geosystem. The imbalance of areas of unstable fragility is due to two distinct processes, the first is related to the dynamic balance of natural components (relief, soil and vegetation cover), which correlate disproportionately, being areas of high declivity, with a small vegetation, which can favor the erosive processes of the soils, and make such areas unstable. It is noteworthy that from the perspective of morphopedological compartmentalization, the steep slope unit of erosion has the highest erosive potential. The second is related to anthropic action, which consisted in the suppressio