ResumoA zona de transição Amazônia-Cerrado é caracterizada pela alta diversidade de ecossistemas, biodiversidade e condições climáticas. Este trabalho tem como objetivo investigar evidências de mudanças climáticas na precipitação e temperatura no Estado do Maranhão. Os dados de normais climatológicas desde 1977 até 2014 provenientes de 12 estações meteorológicas do Instituto Nacional de Meteorologia, distribuídas no Estado foram utilizados para construir a série temporal de dados climáticos. Os dados foram divididos em dois grupos referentes às estações climáticas, seca e chuvosa. O teste de Mann-Kendall foi aplicado para detecção de tendências de aumento ou decréscimo, tanto na série temporal completa, quanto nos dados referentes aos períodos seco e chuvoso. Os resultados evidenciaram uma forte elevação na temperatura do ar em todas estações do Estado. No bioma amazônico em relação a precipitação, as estações de Bacabal e Zé Doca registraram tendências de aumento e diminuição, respectivamente. No bioma cerrado, as estações de Carolina e Colinas apresentaram tendências de aumento e diminuição, respectivamente. Os resultados apresentados neste trabalho mostraram que as mudanças climáticas ocorrem diferentemente no Estado do Maranhão, não necessariamente influenciada pelo bioma. Palavras-chave: mudanças globais, desastres naturais, sensoriamento remoto. Evidence of Climate Change in the Amazon-Savanna Transition Region in Maranhão State AbstractThe Amazon-Savanna transition zone is characterized by high diversity of ecosystems, biodiversity and climatic conditions. This work aims to investigate evidences of climate change on precipitation and temperature in the Maranhão state. The climatological normal data from 1977 to 2014 provided from 12 meteorological stations of National Meteorological Institute distributed in state area was used to build the climatic time series. This dataset was divided in two groups according to climate stations, dry and rain seasons. The Mann-Kendall test was applied to detect increase and decrease trends regarding complete time series and both, dry and rain season series. The results show a strong climate change in air temperature. In the amazon biome, Bacabal and Zé Doca stations registered increase and decrease tendencies, respectively. In the savanna biome, in Carolina and Colinas stations presented increase and decrease tendencies, respectively. The results presented in this work shows that climate change occurred differently in Maranhão state, not influenced necessarily by biome.

The Maranhense Amazon floodplain shelters a Ramsar site established by the United Nations for the protection of wetland biodiversity. Despite its protected ecological status, the impacts from deforestation, burning, the agricultural and livestock industries, are on the rise. Knowledge of the spatial distribution and temporal dynamics of these impacts are important to improve the understanding of how this region is affected. Data on increasing deforestation and hot pixels were used to evaluate the anthropogenic pressure under the geodiversity of the region, relating them to the environmental variables (rainfall, Normalized Difference Vegetation Index and Deforestation annual deforestation rate) measured through the rainfall data and the Normalized Difference Vegetation Index (NDVI). In this study, the potential of remote sensing and geographic information system. The time series were used from 2001 to 2016 for all variables. We observed a strong negative and significant correlation between hot pixels and NDVI, while hot pixels increase, the vegetation indexes tend to decrease. In 2006 an abrupt fall in the NDVI occurred due to the marked increase in the deforested area. In 2010, the NDVI reached its highest levels, because the vegetation responded to the highest rainfall observed in the period in 2009. Unit 4 presented the highest pixels number in the period evaluated (2,978 pixels; 55% of the total). There is a significant correlation between NDVI and rainfall.