2023-06-262023-06-262023-05-26SANTOS, Diogo Corrêa. Mudanças da cobertura, uso do solo e produção de minério de ferro em minas a céu aberto na Austrália e no Brasil: um indicador de intensidade de explotação mineral. Pedro Walfir e Souza Filho . 2023. 106 f. Tese (Doutorado em Geologia) - Programa de Pós-Graduação em Geologia e Geoquímica, Instituto de Geociências, Universidade Federal do Pará, Belém, 2023. Disponível em: https://repositorio.ufpa.br/jspui/handle/2011/15764. Acesso em:.https://repositorio.ufpa.br/jspui/handle/2011/15764Iron ore is a very important resource for the development of a nation. With technological, industrial and urban advances, especially in Asian countries, the demand for this resource has increased considerably in recent decades. Consequently, changes in land cover and use (LCLU) have occurred in the mined areas of countries with higher ore production. Australia and Brazil are the largest iron ore producers in the world. In 2019, they reached production amounts of 930 million tons (mt) and 480 mt, respectively. However, little is known about the extent of land required for iron ore exploitation at the scale of productive open-pit mines in these two countries. Therefore, this doctoral thesis aimed to (1) map the LCLU in time and space in iron mining areas in the countries with the highest production in the world; (2) estimate the area used for iron ore exploitation as well as the accumulated ore production from the 1980s to 2019; and (3) identify an indicator of mineral exploitation intensity and ore production in millions of tons per square kilometer (mt/km²) for the main iron mines in Australia and Brazil. Landsat 5 TM (1984 and 1986) and Sentinel-2B (2019) satellite images were processed to map LCLU in areas of open cast iron mines in the Pilbara region of Western Australia, Hamersley mineral province and in the regions of Carajás (PA), Corumbá (MS) and Quadrilátero Ferrífero, QF, (MG) in Brazil, using geographic object-based image analysis (GEOBIA). The values of iron ore production per mined area were extracted from the statistical yearbooks of mineral production in the two countries. The results showed that iron mining in Australia occupied an area of 41.45 km² in 1986 and was expanded to 875.06 km² by 2019. In Brazil, the extent of iron mining was 109.53 km² in 1984, and this area expanded to 295.75 km² in 2019. The overall accuracy and kappa index of the set of classified images were above 90%, indicating the excellent quality of the classification. The accumulated iron ore production data between 1984 and 2019 showed that Australia reached a total production of 8.4 billion tons of iron ore in this period in a mined area of 875.06 km², equivalent to 9.7 mt/km². Brazil reached a total production of 7.03 billion tons in an area of 297.75 km². The mineral exploitation intensity indicator showed that Brazil and Australia produced equivalents of 23.6 mt/km² and 9.7 mt/km², respectively, over the study period. The study concluded that (1) the area of mined soil increased in all the mines in the two countries analyzed between 1984 and 2019, with the largest expansion being detected in Australia; (2) the high production of iron ore in Australia and Brazil and the consequent LCLU changes are driven by high demand from Asian countries, especially China; and (3) according to the mineral exploitation intensity indicator, there was a better relationship between mineral production and mined area in Brazil than in Australia. This result allows us to confirm that the two countries, especially Brazil, reached extremely high levels of production in a proportionately small area. Finally, this doctoral thesis contributed to the understanding of the intensity of iron ore production and the consequent LCLU changes in these two countries in addition to contributing quantitative and specialized data on the extents of the main iron ore mines globally.Acesso AbertoAttribution-NonCommercial-NoDerivs 3.0 Brazilhttp://creativecommons.org/licenses/by-nc-nd/3.0/br/Minério de ferroSensoriamento remotoMCUSGEOBIAImagens de satéliteTeseCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIAGEOLOGIA MARINHA E COSTEIRAGEOLOGIA