EM - Escola de Minas

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Regionalização da curva de regularização de vazão da bacia do rio Juruena.
(2020) Oliveira, João Paulo de Amorim; Uliana, Eduardo Morgan; Mendes, Múcio André dos Santos Alves; Lisboa, Luana
A regularização de vazão é essencial quando a demanda de água é maior que a vazão mínima. Isso torna necessária a acumulação dos excessos para atender períodos cuja disponibilidade hídrica natural é menor que demanda de captação. Nesse contexto, o objetivo do trabalho foi regionalizar a curva de regularização de vazões para a bacia do rio Juruena de forma a subsidiar projetos de outorga e dimensionamento de reservatórios. Foi gerada curva adimensional de regularização de vazão para sete seções de monitoramento de vazão da bacia. Em seguida foi ajustado o modelo potencial aos dados das curvas de forma a regionaliza-las. As equações de regionalização propostas possuem precisão e acurácia e poderão embasar projetos de regularização de vazão para irrigação, abastecimento público e geração de energia elétrica.
River reorganization affects populations of dwarf cichlid species (Apistogramma Genus) in the Lower Negro River, Brazil.
(2022) Leitão, Carolina Sousa de Sá; Souza, Érica Martinha Silva de; Santos, Carlos Henrique dos Anjos dos; Val, Pedro Fonseca de Almeida e; Val, Adalberto Luis; Almeida Val, Vera Maria Fonseca de
Alterations, such as drainage network reorganization, in the landscape in the Amazon basin influence the distribution range and connectivity of aquatic biota and, therefore, their evolution. River capture is a geomorphic mechanism of network reorganization by which a basin captures large portions of the network of a neighboring basin, thus creating a barrier against species dispersal. In this study, the influence of river capture on the genetic differentiation and structuring of two dwarf cichlids species (Apistogramma pertensis and Apistogramma gephyra) is investigated in two tributaries of the lower Negro River. The analysis of 11 loci microsatellite and three mitochondrial DNA genes (Cytochrome b, Citochrome c Oxidase subunit I and 16S ribosomal RNA) confirmed the populational isolation of two dwarf cichlids species, suggesting that they represent evolutionary significant units (ESU) that have been isolated—probably due to the river capture event. The paleovalley that resulted from the river capture is therefore an important physical barrier that separates the populations of the Cuieiras and Tarumã-Mirim Rivers. The findings herein provide evidence of a mechanistic link between the isolation and differentiation of fish populations and the drainage evolution of the Amazon basin, and indicate that the dynamic geological history of the region has promoted species diversification. The process described here partially explains the high diversity in the genus Apistogramma and the information obtained is beneficial to conservation programs.
Pathways for recent Cerrado soybean expansion : extending the soy moratorium and implementing integrated crop livestock systems with soybeans.
(2019) Nepstad, Lucy S.; Gerber, James S.; Hill, Jason D.; Dias, Lívia Cristina Pinto; Costa, Marcos Heil; West, Paul C.
The Brazilian Soy Moratorium has effectively reduced forest conversion for soybeans in Amazonia. This has come at the expense of the region’s pasturelands, which have increasingly ceded space for compliant soy expansion. The question of extending the policy to the Cerrado, where recent soy expansion has come at the cost of ecologically valuable vegetation, plugs into a wider discussion on how to reconcile competing commodities on finite amounts of cleared area. Innovative management strategies that allow different land uses to coexist are urgently needed. Integrated crop-livestock systems with soybeans(ICLS)rotates beef and soy on the same area, and shows promise as a means to improve production, farmer benefit, and environmental impacts. Here we reconstruct historical land use maps to estimate Cerrado Soy Moratorium outcomes with benchmark years in 2008 and 2014, we then estimate additional production afforded by ICLS implementation between 2008 and 2014. We find that if a 2008 Cerrado Soy Moratorium were in place, 0.7 Mha of 2014 Cerrado soy area would currently be in violation of the policy. Roughly 96% of this acreage is found in Matopiba (82%) and Mato Grosso (14%)states, suggesting that adoption may have slowed recent production in these rapidly transforming soy centers, in contrast to central and southwestern Cerrado where there is more concentrated eligible expansion area. Changing the benchmark to 2014 could have added 0.7 Mha of eligible expansion area, though over 80% of these additions would be in states with the most 2008 eligible area (Distrito Federal, Mato Grosso, Maranhão, Minas Gerais, Mato Grosso do Sul). Meanwhile, ICLS adoption could have added between 4.0 and 32 Mha of new soy land to the study area without additional clearing between 2008 and 2014, though this would depend on rigorous accompanying land zoning policy to guide implementation. The roughly 5 Mha of Cerrado soybean expansion that actually occurred between 2008 and 2014 could have been accommodated on 2008 suitable pasture area given an ICLS rotation frequency of every 6 years or less. Conservation estimates presented here represent the upper limit of what is possible, as our scenario modeling does not account for variables such as leakage, laundering, or rebound effects.

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