Resumo em Português:

Resumo Os campos de murundus, também conhecidos como covoais, são microrrelevos frequentes no Cerrado. Trata-se conjuntos de elevações semicirculares que sobressaem da superfície do terreno, arredondadas ou ovais, com dimensões médias de 70 cm de altura e 6 m de diâmetro. Encontram-se associados a áreas úmidas e vêm sendo impactados pela expansão agropecuária. Os condicionantes de sua distribuição espacial regional são ainda pouco conhecidos. O objetivo deste trabalho foi identificar fatores naturais condicionantes de sua distribuição espacial no SO de Goiás, na Bacia Sedimentar do Paraná. Todas as ocorrências de campos de murundus identificadas pelo projeto Mapeamento dos Remanescentes de Campos de Murundus no Estado de Goiás (SEMAD-GO/LAPIG-UFG) foram comparadas com informações referentes à litologia, à geomorfologia, ao NDWI (Índice de Diferença Normalizada da Água) e ao SMI (Índice de Umidade do Solo). Os índices foram obtidos por imagens orbitais SENTINEL 2-A (MSI) e Landsat 8 (OLI e TIRS). Constatou-se que os campos de murundus ocorrem preferencialmente nas unidades Depósitos Aluvionares, Cachoeirinha, Coberturas Detrito-Lateríticas e Serra Geral. Predominam sob declividades de 0 a 8%, (relevo plano a suave ondulado) e nas áreas de menor densidade de drenagem. O NDWI e o SMI indicaram que os campos de murundus se concentram em superfícies úmidas, ocorrendo com menor frequência em áreas saturadas/muito úmidas e em áreas de umidade moderada, secas e muito secas.

Resumo em Inglês:

Abstract Murundus fields, also known as covoais, are frequent microreliefs in the Cerrado. These are sets of semicircular elevations that protrude from the surface of the land, rounded or oval, with average dimensions of 70 cm in height and 6 m in diameter. The determinants of its regional spatial distribution are still poorly known. This study aimed to identify the natural determinants of its spatial distribution in the Southwest of Goiás, in the Sedimentary Basin of Paraná. All occurrences of murundus fields identified by the project Mapping of Remnant Murundus Fields in the state of Goiás (SEMAD-GO/LAPIG-UFG) were compared with information referring to lithology, geomorphology, NDWI (Normalized Difference Water Index), and SMI (Soil Moisture Index). The indices were obtained from SENTINEL 2-A (MSI) and Landsat 8 (OLI and TIRS) orbital images. It was found that murundus fields preferentially occur in the Alluvial Deposits, Cachoeirinha, Detritic-lateritic Covers, and Serra Geral geological units. Murundus fields predominate under slopes of 0 to 8% (flat to gently undulating relief), and in areas with lower drainage density. The NDWI and the SMI indicated that murundus fields are concentrated on wet surfaces, occurring less frequently in saturated/very wet areas and in moderate humidity, dry, and very dry surfaces.

Resumo em Português:

Resumo As zonas úmidas costeiras são formadas por ecossistemas com potencial para resistir e até se expandirem em decorrência das mudanças climáticas. Para tanto, dependem da preservação da sua qualidade ambiental e dos serviços ecossistêmicos que prestam, entre eles a acumulação de sedimentos, fundamental para a manutenção das áreas atuais, e a presença de áreas terrestres contíguas livres da ocupação humana, permitindo o deslocamento para áreas mais elevadas, acompanhando o nível do mar. De forma a desenvolver uma metodologia para a avaliação conjunta dos impactos das mudanças climáticas e da ocupação do solo sobre ecossistemas costeiros, este trabalho está focado nos mangues da Baía da Babitonga, localizada no litoral norte de Santa Catarina. Utilizando-se projeções de elevação do nível do mar e da expansão da ocupação humana no entorno da baía a partir de dados de cobertura e uso do solo, foi possível identificar efeitos instantâneos do aumento do nível do mar e da ocupação humana a curto, médio e longo prazo, além da área potencial de expansão dos manguezais. Os resultados obtidos indicam a necessidade da expansão de áreas de conservação, considerando-se também zonas de deslocamento em direção ao continente, e no controle dos diversos fatores de estresse que podem interferir na saúde do ecossistema e em sua capacidade de manter as áreas atuais.

Resumo em Inglês:

Abstract Coastal wetlands are formed by ecosystems with the potential to resist and even expand because of climate change. However, they depend on the preservation of their environmental quality and the ecosystem services they provide, including sediment accumulation, which is essential for maintaining current areas, and the presence of contiguous land areas free from human occupation, allowing for migration to higher areas in response to sea-level rise. To develop a methodology for the joint assessment of the impacts of climate change and land occupation of coastal ecosystems, this study focuses on the mangroves of Baía da Babitonga, located on the northern coast of Santa Catarina. By using projections of sea-level rise and human occupation expansion around the bay based on land cover and land use data, it was possible to identify immediate effects of sea-level rise and human occupation in the short, medium, and long term, as well as the potential expansion area for mangroves. The results indicate the need for the expansion of conservation areas, considering displacement zones towards the mainland, and the control of various stress factors that can interfere with the ecosystem's health and its ability to maintain current areas.

Resumo em Português:

Resumo Garimpos de ouro podem ocorrer em terra firme ou em leitos de rios na forma de embarcações. Porém, a atividade precisa estar amparada com uma Permissão de Lavra Garimpeira (PLG), expedida pela Agência Nacional de Mineração, e com a devida licença ambiental do órgão ambiental competente. Nesse sentido, o uso de imagens dos satélites Sentinel-2 se apresenta como ferramenta potencial para identificação de garimpos de ouro embarcados devido à resolução temporal, gratuidade de imagens, cobertura global e resolução espacial mais refinada. Este estudo objetivou identificar garimpos de ouro embarcados no Rio Madeira, próximo à cidade Porto Velho, estado de Rondônia, em 13 imagens Sentinel-2 de 2018 a 2021, a partir dos seguintes classificadores: Support Vector Machine (SVM); K-Nearest Neighbor (KNN); Random Forest (RF); e Spectral Angle Mapper (SAM). Os resultados demonstraram que os classificadores do tipo machine learning obtiveram melhor performance, com destaque para o classificador SVM orientado a objeto que apresentou melhor score F1 médio (0,91). Além disso, o percentual de detecção obtido foi satisfatório com omissão variando de 0 a 4 garimpos ativos por imagem. Assim, a partir dos resultados obtidos, conclui-se que o uso de classificadores machine learning se mostrou eficaz para identificar garimpos de ouro embarcados.

Resumo em Inglês:

Abstract Artisanal and small-scale gold mining can occur on land or in riverbeds. However, the activity needs to be supported by a Mining Permit, issued by the Agência Nacional de Mineração, which is the Brazilian institution responsible for mining management, and the appropriate environmental license from the competent environmental agency. The use of images from Sentinel-2 satellites presents itself as a potential tool for identifying gold mining vessels due to the temporal resolution, free imagery, global coverage, and more refined spatial resolution. So, this study aimed to identify gold mining vessels on the Madeira River near Porto Velho city, Rondônia state, located at Brazilian Amazon, in 13 Sentinel-2 images from 2018 to 2021 using the classifiers: Support Vector Machine (SVM), K-Nearest Neighbors (KNN) Random Forest (RF) and Spectral Angle Mapper (SAM). The results showed that machine learning classifiers obtained the best performance, especially the object-oriented SVM classifier, which had the best average F1 score (0.91). In addition, the detection percentage of gold mining vessels originated by this classifier was satisfactory, with only 0 to 4 active gold mining vessels with sediment plumes being omitted per image. Therefore, based on the results obtained, it was concluded that the use of machine learning classifiers proved to be effective in identifying gold mining vessels.

Resumo em Inglês:

Abstract As the largest carbon reservoir in terrestrial ecosystems, soils play a critical role in food production, mitigation and adaption to climate change, and sustainability of agroecosystems. In this context, the aim of this study is to estimate variations in soil carbon stocks resulting from land use and management changes in different biomes that compose the Bacia Estendida do Rio São Francisco (BESF - Extended São Francisco River Basin), between 1985 and 2017. For this, remote sensing data and information from the IBGE agriculture and livestock census were used, in addition to emission factors to estimate soil organic carbon (SOC) changes. The results indicate that BESF had about 5.70 million ha degraded in the analyzed period, in addition to an increase of 0.72 Tg C year-1 in SOC stocks. The sub-medium São Francisco River basin recorded the highest SOC gain, with an increase of 0.54 Tg C ha-1; on the other hand, the sub-medium São Francisco River sub-basin had the greatest SOC losses, with an estimated reduction of 0.07 Tg C year-1. In short, this study provides important evidence on changes in SOC stocks in the region, emphasizing the importance of native vegetation conversion to agriculture and livestock systems under sustainable soil management for mitigating greenhouse gas emissions and maintaining soil quality.

Resumo em Inglês:

Abstract The Private Reserve of Natural Patrimony (RPPN) of the Santuário of Caraça is found in a mountain region within the Quadrilátero Ferrífero geological province in the State of Minas Gerais. In this region, intense metamorphic processes shaped their siliciclastic rocks, enabling the formation of fractures and diaclasis, the favourite routes of weathering during the development of karst landscapes. The natural cavities thus formed, mainly in the RPPN sector called “Pico do Inficionado”, provide shelter for countless swifts of the species Streptoprocne zonaris and S. biscutata, responsible for the accumulation of guano on the floor. However, guano is a substance rich in nutrients, mainly phosphates and nitrates, and this is the main nutrient supply in permanently dry caves. This work studied the physical (density) and chemical (organic carbon, nitrogen, potassium, phosphorus, sodium, calcium, magnesium, aluminium and pH) characteristics of 21 guanos layers, correlating their contents with the depth of seven deposits and separating the results into factors. Considering that, knowing that the guano deposits contain crucial elements such as Ca, Mg, and especially P and N, which act as an energy source for many chemotrophic organisms, the subdivision of the studied elements allowed us to defer three factors: the first one features the concentrations of Al, P, K, Na and CO, the second one was determined for N, pH and density. Finally, the third factor was based on Ca and Mg. The quartzitic material influences the chemical and physical composition of the deepest guano. As the rock changes, elements like Al and K are released and enrich the deeper layers, as well as increasing density due to the presence of sand in the material.

Resumo em Inglês:

Abstract Water management in the Brazilian semi-arid region has been, for decades, a challenge for institutions and decision-makers due to its intrinsic characteristics. The density of human occupation makes the region very vulnerable to drought events and problems related to the quality and need for water use are central issues. For this reason, this study presents an approach to assess the situation of water reservoirs in the semiarid based on the Water Quality Index (WQI) and Multi-Criteria Decision Making (MCDM). The WQI was used to calculate water quality and later applied as a criterion for the MCDM model proposed. The model also considers the need and availability criteria to assess the reservoirs of the two largest drainage basins in Rio Grande do Norte state, Brazil. The MCDM method used was R-TOPSIS since it is more flexible and robust for future analyses in other situations. The results showed the condition of the reservoirs, in order to support decision-makers in the operation of these facilities and enable multiple use of the waters. The combined approach proposed may provide important contributions in the analysis of water reservoirs in order to supply the semiarid region, where water issue is critical.

Resumo em Inglês:

Abstract In Southeastern Brazil, artisanal fishing communities reside, operate and suffer from interference originating from various economic branches. Thus, this study is aimed at identifying the critical points concerning the practice of artisanal fishing from the traditional knowledge of artisanal fishers in the coastal mesoregion of ES. 102 ethnographic interviews were conducted in 2022 with artisanal fishers through a semistructured questionnaire containing both open and closed questions. The critical points of fishing were identified through a SWOT analysis (strengths, weaknesses, opportunities, and threats). All the participants were men (n=102; 100%), and they reported that negative critical points (weaknesses and threats) exert the greatest influence on fishing. From the perspective of these fishers, the main problems that interfere with artisanal fishing are the lack of adequate fish storage, the precariousness of the vessels, the reduction in fish stocks, the high perishability of fish, the devaluation of traditional knowledge, and the presence of middlemen that prevent the commercialization of fish production from moving directly from the fisher to the final consumer. The identification of these critical points enables the recognition of flaws in the production chain and the realization that they can be minimized through public policies and comanagement strategies related to the economic, ecological, and social development of the sector.

Resumo em Inglês:

Abstract The article approaches the processes of metropolization with regard to urban development and spatial organization of the city in their continuous and articulated processes. The perspective of this analysis is that there is a new basis for urban/metropolitan dynamics, moving out from an industrial and post-Fordist economy to a financialization of the economy, which we call metropolization. From the recent dynamics of the concentration of people and the expansion of urban space, some discussions can emerge about the new socio-spatial reality. Concerning metropolization, our main objective is to discuss the concept of urbanization and metropolization, aiming to understand the spatial transformations of the contemporary world. In methodological terms, we sought a bibliographic survey on the dialogical relationship between urbanization and metropolization with Brazilian and foreign authors who are relevant in the Brazilian academic literature and, in turn, are present in the urban/metropolitan analysis. The presence of temporal, economic and spatial dimensions has been deemed the main drivers for metropolization. As a result, the concept of metropolization was understood as a socio-spatial process that interferes in the forms, functions and dynamics of large urban spaces, and that has been acquiring importance in the context of the contemporary world, being a characteristic that pervades urbanization, reaching both countries in the global South as in the global North.