Práticas de manejo pecuário na microrregião de São Miguel do Araguaia, Goiás: uma análise a partir de dados de campo e de sensoriamento remoto

• Autor(a) principal: Aguado, Oscar Ivan De Oro
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/6854
• topic: Pastagem; Degradação; Série temporal; Tendência; Pastizales; Degradación; Serie temporal; Tendencia; TECNOLOGIA DE ARQUITETURA E URBANISMO::ADEQUACAO AMBIENTAL

Pasture degradation is a process in the tropical region and in Brazil, it is estimated that there are approximately 100 million hectares under poor conservation and management conditions. This work aims to understand, in an exploratory way, the quality of the Brachiaria Brizantha and Andropogon Gayanus species, evaluating the seasonal and trend characteristics in relation to the conditioning factors of the degradation in the microregion of São Miguel do Araguaia. The methodology consisted in the selection of pastures in three levels of degradation for the species mentioned above; historical management for the last 15 years; and estimated vegetative vigor analysis using satellite images from the MODIS sensor, i.e. product MOD13Q1 - NDVI, for the period 2000 to 2015. The time series was analyzed using seasonal metrics and the algorithms Breaks For Additive Season and Trend (BFAST) for trend analysis and identification of the degradation factors for the three levels of degradation of both species. The results demonstrated the differentiation between the three categories of pasture management (optimal, reasonable and poor) for the two grass species using data collected in the field and orbital. According to the seasonal metrics, statistically, the species presented differentiated vegetative vigor behaviors (t = 2,083, gl = 375, p <0.001), and the discrimination is higher using the amplitude and maximum metrics of the NDVI index. The optimal pastures (t = 2.876, gl = 375, p <0.001) and poor (t = 4,142, gl = 375, p <0.001) differed according to seasonal behavior, while reasonable pastures did not (t = 0.745; = 375, p> 0.05). The optimal and reasonable pastures of B. Brizantha presented similar behaviors over the analysis period, whereas the poor pasture presented differentiated behaviors for the amplitude and average metrics. However, the optimal, reasonable and poor pastures of the A. Gayanus species, despite having differentiated qualities and management in the field, the NDVI values throughout the temporal series presented similar behaviors for both qualities. The Trends analysis showed that the high temperatures of 2007 and 2010 generated negative breaks points for both species, while the years of 2009 and 2013 were points of positive breaks due to the increase in rainfall records. As a conclusion, moderate resolution orbital data, particularly NDVI, allow the differentiation of pasture species and their respective qualities through the analysis of time series and, on the other hand, trend analysis showed that both species of grass showed high Sensitivity to the climatic factors, as El Niño and La Niña, in relation to the management used.