Biblioteca Digital de Teses e Dissertações. https://repositorio.ufra.edu.br/jspui/handle/123456789/16 2026-07-07T22:27:12Z 2026-07-07T22:27:12Z MELO http://lattes.cnpq.br/3542869559542094, Adriana da cruz banca 1 ALVES JÚNIOR http://lattes.cnpq.br/2566643607928091, Flavio de Almeida banca 2 LIMA http://lattes.cnpq.br/8021186707342335, Mauricio Willians de https://orcid.org/0000-0001-9092-8731 banca 3 CHAGAS http://lattes.cnpq.br/9393899936340805, Rafael Anaisce das https://orcid.org/0000-0002-1555-6154 https://repositorio.ufra.edu.br/jspui/handle/riufra/2891 2026-06-18T13:32:32Z 2026-05-22T00:00:00Z

Título: Avaliação das águas superficiais da bacia hidrográfica do baixo tocantis, Pará, Brasil: Um panorama no espaço e no tempo Autor(es): MELO http://lattes.cnpq.br/3542869559542094, Adriana da cruz; banca 1 ALVES JÚNIOR http://lattes.cnpq.br/2566643607928091, Flavio de Almeida; banca 2 LIMA http://lattes.cnpq.br/8021186707342335, Mauricio Willians de https://orcid.org/0000-0001-9092-8731; banca 3 CHAGAS http://lattes.cnpq.br/9393899936340805, Rafael Anaisce das https://orcid.org/0000-0002-1555-6154 Abstract: Preserving water quality is essential for human survival and environmental conservation. Despite Brazil possessing the largest amount of freshwater in the world, it faces a water crisis throughout its territory due to problems such as lack of sanitation, pollution from agriculture, and lack of water reuse. The Tocantins-Araguaia River basin, the second largest in the country, encompasses a vast area with 430 municipalities distributed across the states of Pará, Maranhão, Tocantins, Goiás, and Mato Grosso. This study focuses on the Lower Tocantins region in northeastern Pará, where abiotic and biotic water parameters will be evaluated to understand the environmental dynamics. Factors such as land use, anthropogenic actions, and periods of intense rainfall influence water quality, increasing turbidity and nutrient levels, such as nitrogen and phosphorus, which can lead to eutrophication. CONAMA Resolution 357/2005 is a fundamental instrument for monitoring water quality standards in Brazil, contributing to the sustainable use of this vital resource. This study aimed to evaluate environmental parameters, calculate the Trophic State Index (TSI), and analyze the influence of seasonality, focusing on eleven points distributed across seven municipalities in Pará state, in order to support the planning of water preservation actions in the region. The results show the influence of seasonality on water quality, with higher values of electrical conductivity in the less rainy period (79 μS cm⁻¹) compared to the rainy period (65 μS cm⁻¹), indicating a higher concentration of dissolved ions. Chlorophyll a was also higher in the less rainy period (12.2 μg L⁻¹) compared to the rainy period (9.8 μg L⁻¹), suggesting a greater supply of nutrients. Turbidity was higher during the less rainy period (97 NTU), while dissolved oxygen remained close to 6.4 mg L⁻¹ in both periods. The Trophic State Index ranged from 51.32 to 52.11, indicating a mesotrophic condition and the influence of seasonality on the limnological dynamics of the region.

2026-05-22T00:00:00Z MARTINS, Ana Regina Araújo https://repositorio.ufra.edu.br/jspui/handle/riufra/2888 2026-06-10T12:14:55Z 2001-01-01T00:00:00Z

Título: Dinâmica de nutrientes na solução do solo em um sistema agroflorestal em implantação. Autor(es): MARTINS, Ana Regina Araújo Abstract: The agroforestry systems constitute an alternatíve to produce foods, wood and other non-wooden products, also playing an excellent role in the conservation and maintenance ofthe functions oftropical ecosystems. That being so, a agroforestry system with maize, cowpea, jack beans and cassava in rotation were studied in the area of CEPLAC, following the procedures ofthe Program" SHIFT - Studies on Human Impact on Forests and Floodplains in the Tropics ", in Benevides, Pará, near Belém. During the studied period between 1995/1996, the following parameters were registered: precipitation and saturation ofthe soil water (tensiometers in the depths 10, 45 and 145 cm), the chemical composition of the solution of rain (rain gauges) and the ground (lysimeters in depths 25, 40, 60 and 110 cm), the exported harvest ofthe field and its content of nutrients, and the residue from the remaining biomass in the field and its content of nutrients. The emphasis was in the study of the fluctuations in the chemical composition ofthe soil solution and in its dependence on the human activity in the field, aiming to get adaptable information to the reality ofsmall and medium producers. The most important observation verified was that the N was the element with the biggest relative importance in this work, for being present in bigger amounts in the soil solution in the band of25 cm, followed by the Ca, Mg, K, CI and Na. The effective participation ofthe CI and the Na in the cycling processes was a surprise, probably generated by the high amount ofthese in the rainwater. The S-SO4 and the AI had little importance for presenting small amounts. The other elements, Fe, Mn, H, P-PO4 appear in very low amounts. A system of rotational handling, and in association, suggests a faster and more intensive dynamics, thus the concentration of the elements studied in the soil solution was always higher in the agroforestry system than that in the forest. However, the observations during the studied period showed that the Na, CI and AI are less sensitive to the handling of the vegetation, whereas the Ça, Mg, K, N-NH4, N-N03 and S-S04 are more affected by the developed activities inside the agroforestry system. Specifically regarding the Na and CI, the concentration of these elements in the forest suffered influences :from the action of rain, :from impact of the dry deposition (bum) and :from the sea water, even so the participation of these ones in the agroforesty system is corroborated. The handling activities developed inside the agroforestry system (plantation, weeding, thinning, harvesting, pruning) generated additions and losses of nutrients promoting a fluctuation in the course of time. These fluctuations were observed mainly for the Ca, K, N-N03, CI and Na. The K was put into motion faster than the Ca in the soil solution. The S-S04 presented a small fluctuation, contrary to the N-N03 and the Cl. For the N-N03, Ca, Mg and K, the cause of the fluctuations was the sarne, that is, release and absorption.

2001-01-01T00:00:00Z COSTA, Izabelle Tavares da https://repositorio.ufra.edu.br/jspui/handle/riufra/2887 2026-06-09T19:41:43Z 2026-01-01T00:00:00Z

Título: Decifrando os desembarques de grandes bagres migradores: Como as características operacionais e sazonais moldam a pesca no estuário Amazônico? Autor(es): COSTA, Izabelle Tavares da Abstract: Fishery resources play an important role in the global economy. In the Amazon, fishing is a traditional and economically significant activity that provides both income and food security. Amazonian fish production is dominated by large migratory catfish species, such as piramutaba, dourada, and filhote, which depend on extensive migrations to complete their life cycle. Analyzing fishery activity data is an indirect approach to assessing fish populations. This study aimed to investigate the operational, spatial, and temporal characteristics that influence the occurrence and intensity of catches of B. rousseauxii, B. vaillantii, and B. filamentosum at the mouth of the Amazon River. Using advanced statistical tools, we evaluated the relationship between the CPUE of B. rousseauxii, B. vaillantii, and B. filamentosum as a function of seasonality and fishery operational characteristics, such as fishing area and vessel fishing power in the Amazon estuary. To account for zero-inflated data, a Hurdle model was applied, allowing a two-part structure: a binary component indicating the absence of CPUE and a continuous component modeling positive CPUE values. The CPUE of dourada is influenced by vessel classification and by the interaction between area and period. The CPUE of piramutaba varies with fishing area and period, and the effect of the period changes depending on the area. The CPUE of filhote varies with vessel type, area, and period, and the effect of the period also changes according to the area. These findings underscore the need for management strategies that incorporate the seasonality and spatial heterogeneity of fishing in the Amazon estuary.

2026-01-01T00:00:00Z SIMÔES, Lourdes Henchen Ritter https://repositorio.ufra.edu.br/jspui/handle/riufra/2886 2026-06-09T14:44:57Z 2026-05-11T00:00:00Z

Título: Influência da cobertura pedológica na utilização do solo na localidade de Benfica, município de Itupiranga, PA. Autor(es): SIMÔES, Lourdes Henchen Ritter Abstract: L'étude du sol dans le contexte de Tagriculture familiale en front pionnier est importante pour mettre en évidence les correlations entre les systèmes pédologiques, leurs potentiels et leurs limitations et les modes d'utilisation agricole locale. La principale fmalité de ce travail est d'identifíer la diversité des types de sois, leurs aptitudes culturales et comment ils sont utiiisés par les agriculteurs, à partir d'observations morphologiques sur trois toposséquences de sois formées sur deux roches (monzogranite et granodiorite), et d^ntretiens avec les agriculteurs Socaux. Les résultats montrent quMl existe une diversité de sois avec des potentiels agronomiques variés, offrant des alternatives durables pour Tagriculture et le maintien des exploitations. Cette diversité de systèmes pédologiques dans Ia plupart des cas n/est nas prise en compte par les agriculteurs. Cependant cette attitude est liée à une stratégie de production bovine dans laquelle les intérêts paraissent être la valorisation du lot en pâturage pour une vente future. Toutefois, quelques agriculteurs adoptent des stratégies dê diversificâtion du système de production et, alors, les différents types de sois sont considérés. Dans ce cas rexpioitation devient plus viable, garantissant pour une plus grande période le maintien de la capacité productive du milieu.

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