Modelagem hidrológica na bacia do rio Capim – estado do Pará.

CAPESEste estudo visa à estimativa dos componentes do ciclo hidrológico, com o modelo Soil and Water Assessment Tool (SWAT) para a bacia do Rio Capim, localizada nos estados do Pará e oeste do Maranhão, no período de janeiro de 2000 a dezembro de 2010. Foram utilizados dados meteorológicos de uma estação automática de Paragominas, além dos dados pluviométricos e fluviométricos (Agência Nacional de Águas – ANA). O clima na área de estudo tem sazonalidade bem definida, com períodos chuvosos de janeiro a maio e secos de junho a dezembro. De maneira geral, os resultados do modelo SWAT foram satisfatórios quando comparados com outros estudos realizados em bacias pelo Brasil, vale ressaltar que este estudo é pioneiro com o modelo SWAT para uma bacia no estado Pará. Dada a relevância dos recursos hídricos que essa bacia possui, ele pode certamente poderá contribuir para uma melhor gestão e planejamento dos recursos ambientais oferecidos pela bacia do Rio Capim. Dados médios mensais de vazão do Rio Capim foram utilizados para a validação do modelo SWAT, o que resultou em valores de Coeficiente de Eficiência (COE) que se situaram entre 0,59 a 0,65 (para as sub-bacias 3 e 5) e 0,87 para todo o período investigado (de 2000 - 2010). Observou-se ainda que, em termos percentuais, a vazão mensal simulada pelo modelo SWAT, na bacia do Rio Capim, após os ajustes, apresentou uma redução no seu erro de estimativa, que partiu de uma superestimativa de 210,75% até chegar a uma subestimativa de 26% (na sub-bacia 3), e de 219,18% para 18 % (na sub-bacia 5), respectivamente. Em síntese, foi possível espacializar os componentes do ciclo hidrológico e validar o modelo SWAT, o que poderá ser útil em estudos posteriores da bacia do rio Capim.The model Soil and Water Assessment Tool (SWAT) is used in order to estimate the hydrological cycle components of the Capim River basin, which is located in Brazilian states of Pará and Maranhão, from January 2000 up to December 2010. Data from an automatic meteorological station located at Paragominas city have been used, in addition to rainfall and stream flow data provided by the National Water Agency (ANA). The climate in the study area has well defined seasonality with rainy periods from January to May and dry periods from June to December. In general, the results of the SWAT model were satisfactory when compared with other studies ones regarding Brazilian river basins. Interestingly, this study is a pioneer in the application of the SWAT model for research of watersheds in Pará state. Given the importance of this basin’s water resources, this work can certainly contribute to a better management and planning of the environmental resources provided by the Capim River basin. Monthly flow data of the Capim River were used to validate the model SWAT, which has resulted in values of the coefficient of efficiency (COE) which ranged between 0.59 to 0 .65 (for the sub-basins 3 and 5) and 0.87 for the whole investigated period (2000-2010). It was also observed that , in percentage terms, the Capim River monthly runoff simulated by the SWAT model, after some adjustments, presented a reduction in its estimation error, which started from an overestimation of 210.75% until to reach an underestimation of 26% (in the sub-basin 3), and 219.18% to 18% (in the sub-basin 5), respectively. Overall, it was possible to spatialize the components of the Capim River basin hydrological cycle and to validate the model, what may be useful in further studies concerning this hydrological basin

Riscos ambientais e segurança do coletor no extrativismo do fruto de açaízeiro na Amazônia Oriental

The extraction of non-timber forest products in the Amazon is an activity that exposes workers to environmental risks that can affect their health and safety at work. The aim of this study was to identify the environmental risks and the psychophysiological and physical impacts of the collection of the açaizeiro fruit on workers in eastern Amazon. The study was carried out by applying semi-open questionnaires and structured interviews based on protocols of the Ergolândia version 6.0 software to 33 collectors in Ilha do Combú, Belém, Pará state. The physical risks identified were: ultraviolet radiation (12 h of sunlight), average annual relative humidity of 71.9% and heat with IBUTG of 24.4ºC. The fear of falling down from the açaizeiro tree, venomous animals, height and the high physical effort required to climb the palm tree were the main difficulties pointed out by extractivists. The risks of accidents were identified: snake, maribondo, scorpion, spider, açaizeiro fall, cuts, scratches and muscular torsion. The cargo transported by the 30 kg collectors meets the requirements of current legislation. The parts of the bodyO extrativismo de produtos florestais não madeireiros na Amazônia é uma atividade que expõe o trabalhador a riscos ambientais que podem afetar sua saúde e sua segurança no trabalho. O objetivo deste estudo foi identificar os riscos ambientais e os impactos psicofisiológicos e físicos da coleta do fruto do açaizeiro no trabalhador da Amazônia Oriental. O Estudo foi realizado pela aplicação de questionários semiabertos e entrevistas estruturadas baseadas a partir de protocolos do software Ergolândia versão 6.0 a 33 coletores na Ilha do Combú, Belém/PA. Os riscos físicos identificados foram: radiação ultravioleta (12 h de sol), umidade relativa média anual de 71,9% e calor com IBUTG de 24,4ºC. O medo da queda do açaizeiro, animais peçonhentos, altura e o alto esforço físico requerido para escalar a palmeira foram as principais dificuldades apontadas pelos extrativistas. Foram identificados os riscos de acidentes: cobra, maribondo, escorpião, aranha, queda do açaizeiro, cortes, arranhões e torção muscular. A carga de 30 quilos, transportada pelos coletores, atende ao estabelecido pela legislação vigente. As partes do corpo que os extrativistas sentem dores com frequência durante e após a atividade foram: a parte inferior das costas, pés e dedos, mãos e dedos, membros superiores, ombro, punho, trapézio, cabeça e peito, pescoço, antebraço, cotovelo, panturrilha, tornozelo e joelho. O protocolo de Moore e Garg classificou a atividade como de alto risco para o desenvolvimento de doenças ocupacionais com Strain Index de 13,5 e 10,12 na safra e entressafra, respectivamente, e o protocolo de Lehmann como um trabalho fatigante. A OWAS indicou a categoria de ação 4 com adoção de correções imediatas na postura da coluna, membros superiores e pernas dos extrativistas

USO DO MODELO AQUACROP PARA O FEIJÃO-CAUPI CULTIVADO SOB DIFERENTES LÂMINAS DE IRRIGAÇÃO EM CASTANHAL-PA

O feijão-caupi possui grande importância socioeconômica para a população, principalmente a de baixa renda. O modelo AquaCrop foi calibrado e validado para analisar a sua eficiência na simulação do teor de água no solo, produção de biomassa e produtividade do feijão-caupi sob diferentes disponibilidades hídricas no nordeste paraense. O experimento foi realizado na fazenda escola da UFRA-Castanhal, com a cultivar BR3-Tracuateua submetida a quatro tratamentos (T100, T50, T25 e T0), correspondentes à reposição da água perdida pela (ETc) durante a fase reprodutiva, em seis blocos ao acaso. Para a parametrização e calibração do modelo foi utilizado dados coletados em campo nos anos de 2015/2016. O seu desempenho foi avaliado pelos parâmetros estatísticos (RMSE, r², d, c e Ef). O modelo subestimou a biomassa dos tratamentos (T50, T25 e T0), entretanto a biomassa simulada apresentou alta correlação com a observada em todos os tratamentos, bem como um alto índice de desempenho. No geral, o modelo simulou bem a produtividade nos diferentes tratamentos e seus valores apresentaram alta correlação com os dados observados (r2 = 0,99), demonstrando um ótimo desempenho na simulação da produtividade do feijão-caupi (c = 0,98). O desempenho diminuiu em decorrência da lâmina aplicada (T100 > T0), não afetando sua eficiência (Ef > 0,67), decorrente da alta correlação (r² > 0,74) entre os valores observados e simulados e pelos erros de estimativa (RMSE < 20%) aceitáveis, viabilizando seu uso na simulação da biomassa, rendimento além de poder ser usado na simulação do teor de água no solo em Castanhal-PA

Simulation of Flow in the Capim River (PA) using the SWAT Model

ABSTRACT Flow in the Capim River watershed, located in the state of Pará, Brazil, was estimated using the Soil and Water Assessment Tool (SWAT) model in order to determine its use efficiency. The meteorological data (from 2000 to 2010) were collected from an automatic station located in the municipality of Paragominas. The pluviometric and fluviometric data are available at the National Water Agency (ANA) website. Overall results show Efficiency Coefficient (Eff) values of 0.65 (for sub-basin 5) and 0.87 for the entire investigated period. The results also show a reduction in Eff estimation error, which started from over-estimation of 219.18% and declined to underestimation of 18% (in sub-basin 5). In summary, validation of the SWAT model was successful after adjusting the sensors during the calibration phase. Thereby, this model can be used in other studies evaluating river basins

The SWAT Model as Tool for Water resources Management: an example applied to Apeú river in Castanhal/PA.

O gerenciamento dos recursos hídricos tem impulsionado pesquisas, que buscam alternativas de conhecimento dos processos ocorridos em bacias hidrográficas. Diante disso, este estudo teve como objetivo aplicar o modelo SWAT (Soil & Water Assessment Tool) como ferramenta complementar para o gerenciamento de recursos hídricos. O modelo foi utilizado na bacia do Rio Apeú, de 2009 a 2017, para a obtenção de informações sobre a dinâmica do ciclo hidro lógico, a partir das variáveis climáticas, tipo e uso do solo, estas informações podem auxiliar no planejamento da gestão dos recursos hídricos. Durante a calibração do modelo, foi obtida uma boa eficiência (Nash-Sulticliffe) com um valor de 0,89, que foi alcançada pela correlação (R2 = 0,99) entre os valores simulados e observados e pelos baixos valores de erro durante a simulação da vazão. Estes resultados mostram que o modelo pode auxiliar na geração de informações em áreas que não possuem monitoramento e assim obter um melhor planejamento dos recursos hídricos para as bacias.The water resources management has driven researches, which search for alternatives to the understanding about processes occurring in river basins. Therefore, this study aimed to apply the SWAT model (Soil & Water Assessment Tool) as complementary tool for water re sources management. The model was used in Apeú River Basin, from 2009 to 2017 to obtain information on the hydrological cycle dynamics based on climatic variables, type and land use. This kind of information can help in the planning of water resources management. During the model calibration, it obtained good efficiency (Nash--Sulticliffe) with a value of 0.89 which was achieved by the correlation (R² = 0.99) between the simulated and observed values and by the low error values during the flow simulation. These results showed that the model can help in the generation of information for areas wi thout monitoring, and consequently it can help the best planning of water resources for basins

WATER DEMAND, CROP COEFFICIENT AND UNCOUPLING FACTOR OF COWPEA IN THE EASTERN AMAZON

Cowpea has great socioeconomic importance in the northeastern part of Pará state. However, in order to provide suitable irrigation management during the dry period this region requires solid information regarding water demand by regional crops. This research aims to determine the water demand, the crop coefficient (Kc) and the uncoupling factor during the different development stages of cowpea in the northeast of Pará. The crop evapotranspiration (ETc) was measured by drainage lysimeters. This information was coupled to the reference evapotranspiration (ETo) to obtain the crop coefficients, which were used to adjust the model function of accumulated degree-days and the leaf area index (LAI). The uncoupling factor was estimated to indicate the factors that control evapotranspiration. The ETc values reached a cumulative total of 267.73 mm ± 10.21 mm during the cowpea cycle. The average value of the uncoupling factor was 0.66. This indicates that the cowpea crop does not fully uncouple from the atmosphere underneath the climatic conditions in northeast Pará. The cowpea Kc values presented averages of 0.8, 1.4 and 0.8 in the vegetative phase, reproductive phase and final stage, respectively. The Gaussian model showed an excellent fit for the estimation of Kc values based on accumulated degree days and the LAI. These amounts differ from others found in the literature. Therefore, it reinforces the necessity for an assessment of crop coefficients under local conditions and for the employment of more precise methods

Temperaturas basais e exigências térmicas do açaizeiro na Amazônia Oriental

The objective of this work was to determine the base temperatures, thermal time requirements, and length of the main reproductive growth stages of acai palm (Euterpe oleracea) in the northeast of the state of Pará, in eastern Amazon, Brazil. The experiment was carried out from 2017 to 2019 in a 10 ha acai plantation, using the time-series analysis. Plant phenology was monitored weekly, and local weather conditions were monitored daily. The lower and upper base temperatures were of 12.92 and 32.46°C, respectively, for pre-flowering; 13.50 and 32.23°C for flowering; 12.14 and 32.55°C for green fruit stage; 11.64 and 32.78°C for fruit color-changing stage; and 11.23 and 32.94°C for maturation. The thermal time requirement and the average cycle length for the ideal harvest time of acai palm were 3,893.15 degree-days and 283 days, respectively. The thermal time requirement and the duration of the reproductive growth stage for acai palm are influenced by the period of the year and the variability of air temperature, which, when high, reduces the cycle of the crop, and when mild, increases it.O objetivo deste trabalho foi determinar as temperaturas basais, as necessidades térmicas e a duração dos principais estádios fenológicos reprodutivos do açaizeiro (Euterpe oleracea) no Nordeste do estado do Pará, na Amazônia Oriental, Brasil. O experimento foi realizado de 2017 a 2019, em plantio de açaizeiro de 10 ha, tendo-se utilizado análise de série temporal. A fenologia das plantas foi monitorada semanalmente, e as condições meteorológicas dos locais foram monitoradas diariamente. As temperaturas basais inferiores e superiores foram de 12,92 e 32,46°C, respectivamente, na prefloração; 13,50 e 32,23°C na floração; 12,14 e 32,55°C no estádio de frutos verdes; 11,64 e 32,78°C no estádio de mudança de cor dos frutos; e 11,23 e 32,94°C na maturação. A exigência térmica e a duração média para o ponto ideal de colheita do açaí foram de 3.893,15 graus-dias e 283 dias, respectivamente. A exigência térmica e a duração dos estádios da fase reprodutiva do açaizeiro são influenciadas pelo período do ano e pela variabilidade da temperatura do ar, que, quando elevada, reduz o ciclo da cultura, e, quando amena, o estende

Performance of Cowpea under Different Water Regimes in Amazonian Conditions

Water availability is a crucial factor in the final productivity of cowpea. The objective of this work was to evaluate the production and productivity components of cowpea under different irrigation depths in Amazonian conditions. The experiment was carried out at the School Farm of the Federal Rural University of Amazonia, in the municipality of Castanhal-PA, using the cultivar BR3 Tracuateua, from September to November 2014, 2015, and 2016. The experimental design was conducted on six blocks and four treatments, where the four irrigation depths of 0, 25, 50, and 100% of crop evapotranspiration were tested. The productivity analysis was performed when 90% of the plants were in the phenological stage R9. The evaluated production components were pod length, number of pods per plant, number of grains per pod, mass of one hundred grains, and harvest index. There was a statistical difference among all treatments for the components of production and among productivities. An average reduction of 827 kg ha&minus;1 in cowpea productivity was observed during the three years of study, when the treatment without irrigation was compared with the treatment irrigated with 100% of the crop&rsquo;s water demand. It was found in this research that the simple fulfillment of the nutritional and phytosanitary demands of the crop, associated with an adequate planning of when to plant in the region, would already help in the improvement of local production when choosing times where the water deficit in the reproductive phase is less than 33 mm

Performance of Cowpea under Different Water Regimes in Amazonian Conditions

Water availability is a crucial factor in the final productivity of cowpea. The objective of this work was to evaluate the production and productivity components of cowpea under different irrigation depths in Amazonian conditions. The experiment was carried out at the School Farm of the Federal Rural University of Amazonia, in the municipality of Castanhal-PA, using the cultivar BR3 Tracuateua, from September to November 2014, 2015, and 2016. The experimental design was conducted on six blocks and four treatments, where the four irrigation depths of 0, 25, 50, and 100% of crop evapotranspiration were tested. The productivity analysis was performed when 90% of the plants were in the phenological stage R9. The evaluated production components were pod length, number of pods per plant, number of grains per pod, mass of one hundred grains, and harvest index. There was a statistical difference among all treatments for the components of production and among productivities. An average reduction of 827 kg ha−1 in cowpea productivity was observed during the three years of study, when the treatment without irrigation was compared with the treatment irrigated with 100% of the crop’s water demand. It was found in this research that the simple fulfillment of the nutritional and phytosanitary demands of the crop, associated with an adequate planning of when to plant in the region, would already help in the improvement of local production when choosing times where the water deficit in the reproductive phase is less than 33 mm