Os Impactos das Alterações Climáticas na Cana-de-Açúcar Cultivada em Sistema de Sequeiro na Região Nordeste do Brasil (The Impacts of the Climate Changes on Sugar Cane Cultivated in Rainfed Systems in Northeastern of Brazil)

Os impactos das alteracoes climaticas sobre o zoneamento agricola de risco climatico do cultivo da cana-de-acucar ( Saccharum officinarum L .) na regiao Nordeste do Brasil (NEB) sao analisados neste estudo. Foram utilizadas as series historicas de precipitacao pluvial com no minimo 30 anos de dados diarios, bem como o coeficiente de cultivo, a evapotranspiracao potencial e a duracao do ciclo da cultura. Adotou-se como criterio de corte para o Indice de Satisfacao das Necessidades de Agua para a cultura (ISNA), o valor 0,65. Os cenarios utilizados de alteracoes climaticas foram sem aumento na temperatura do ar e com aumentos de 1,5, 3 e 5oC associados as variacoes na precipitacao de ± 10, 25 e 40%. Os cenarios de mudancas climaticas analisados indicam reducao consideravel nas areas agricultaveis favoraveis ao cultivo da cana-de-acucar no NEB, afetando assim, as areas de producao da cultura. Existe diferenca relevante entre os cenarios sem aumento na temperatura do ar e os tres cenarios de aquecimento global. Palavras-chave: Mudancas climaticas, zoneamento agricola, evapotranspiracao, precipitacao pluvial. The Impacts of the Climate Changes on Sugar Cane Cultivated in Rainfed Systems in Northeastern of Brazil ABSTRACT The impacts of climate change on agricultural zoning of climate risk of sugar cane ( Saccharum officinarum L. ) in northeastern region of Brazil ( NEB, in portuguese) are analyzed in this study. It was used daily rainfall time series with at least 30 year as well as crop coefficients , potential evapotranspiration and length of crop cycle . It was adopted as criterion the value threshold of 0,65 for Water Requirements satisfaction index (WRSI) . The scenarios used of climate change were no increase in air temperature and increases of 1.5 , 3.0 and 5.0o C associated to changes in rainfall of ± 10 , 25 and 40 %. The analyzed climate change scenarios indicate a significant reducing in agricultural areas favorable to the cane sugar cultivation in the NEB , and therefore affecting the agricultural areas of sugar cane. There is a significant difference between the scenarios with no increase in temperature and three scenarios of global warming. Key words : Climate changes, agricultural zoning , evapotranspiration, precipitation .