Meteorologia Aplicada
URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/6657
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Resultados da Pesquisa
Item Remote sensing-based water resource diagnosis in regions with intensive expansion of irrigation in Brazil(Universidade Federal de Viçosa, 2024-02-20) Santos, Ana Beatriz dos; Costa, Marcos Heil; http://lattes.cnpq.br/1277129685383769Center pivot irrigation has been leading irrigation growth in Brazil in recent years. However, the intensification of climate change effects may lead to issues in regions highly occupied by center pivots. The reduction in precipitation volume or the duration of the dry season often generates conflicts over water usage between irrigators and other water users. Therefore, formulating a diagnosis of the hydrological situation in these regions is crucial. This study selected three Brazilian regions with intensive irrigation expansion: the Corrente and Grande rivers' basins in Bahia and the Alto Rio das Mortes in Mato Grosso. Although these are considered areas with a high technological level in the field, there is no systematic measurement network for water usage yet. Remote sensing products enable the estimation of center pivot water demand through evapotranspiration (ET). For the Corrente and Grande River basins, the MODIS ET product (MOD16A2 Version 6 Evapotranspiration/Latent Heat Flux product) was applied to identify sub-basins with a higher risk of water conflicts. After comparing the estimated irrigation water demand with river flow data, three sub-basins demonstrated a potentially critical situation regarding water resource usage. An in-depth analysis of these sub- basins also revealed that water use by center pivots has steadily increased over the years, pushing water consumption to its limits. In addition to the MODIS product, another database was applied to estimate the irrigation by center pivots, the daily evapotranspiration dataset provided by the GLODET (Global Daily evapotranspiration) platform for the Alto Rio das Mortes. Moreover, ET data measured via eddy covariance were used to assess the accuracy of the two products. The results showed that the new ET dataset exhibited improvements compared to the previous version used, which underestimates evapotranspiration in the region. Additionally, the results represent a first step in understanding irrigation in Mato Grosso, showing immense potential for application in future studies. Keywords: Center pivots; Remote sensing in agriculture; Water security.Item The role of large slaughterhouses on sustainable intensification of cattle ranching in Amazonia and Cerrado(Universidade Federal de Viçosa, 2018-03-02) Santos, Ana Beatriz dos; Costa, Marcos Heil; http://lattes.cnpq.br/1277129685383769Due to their location at the agricultural frontier, their interactions with ranchers and their market domination, large slaughterhouses are potential leverage points in the beef supply chain for achieving sustainable beef production in Brazil. However, their actual role in promoting sustainable production has not yet been ascertained. This dissertation analyzes changes after the start of operation of several large slaughterhouses for five variables: three related to agricultural intensification – protein and calorie production from crops and cattle stocking rate – and two related to environmental impact – land use change rate and greenhouse gas emissions. I focus my analysis on the large slaughterhouses located in the two most important Brazilian biomes for cattle ranching, Amazonia and the Cerrado. First, I selected 12 large slaughterhouses that started operations midway between 2000 and 2013, and I delimited their influence zones. Second, I delimited control zones in regions far from the influence of large slaughterhouses and outside conservation units and indigenous lands. Next, I calculated changes in the five study variables over the study period. In the Amazon, the results show a reduction of the land use change rate and greenhouse gas emissions in both the influence zones and the control zones. For the intensification variables, protein and calories from crops increased significantly in both zones, while the stocking rates do not change in the zones under slaughterhouse influence. In the Cerrado, all variables show the same responses in both the influence and control zones. These results do not support the idea that the large slaughterhouses promote either intensification of cattle ranching or improvements in the sustainability of cattle ranching activity in the Amazon and the Cerrado.