Publicações

Agreement for the UK and Brazil to work together on climate-change issues was reached when President Lula visited the UK in March 2006. Today, our two countries still work together, with the same sense of urgency his visit inspired, to assess the impacts of climate change on Brazil and the effects of deforestation on the Brazilian climate. This report highlights what has been achieved so far through the cooperation and expertise of INPE and the Met Office.

Quando visitou o Reino Unido em março de 2006, o presidente Lula firmou um acordo de trabalho conjunto entre Reino Unido e Brasil sobre questões relativas às mudanças climáticas. Atualmente os dois países ainda continuam trabalhando juntos, com o mesmo senso de urgência que a visita do presidente inspirou, para avaliar os impactos das mudanças climáticas e os efeitos do desmatamento sobre o clima do Brasil. Este relatório destaca o que se conseguiu até agora por meio da cooperação e da engenhosidade do INPE e o Met Office Hadley Centre (MOHC).

O 2º Relatório de Atividades do Instituto Nacional de Ciência e Tecnologia para Mudanças Climáticas (INCT para MC) apresenta os destaques científicos de seus 26 sub-projetos de pesquisa, no período de setembro de 2010 a agosto de 2011. Traz ainda uma descrição resumida dos objetivos, da organização, da infraestrutura e do processo de formação de recursos humanos desta que constitui a maior e mais abrangente rede interdisciplinar de instituições de pesquisa em meio ambiente no Brasil.

O 2º Relatório de Atividades da Rede Brasileira de Pesquisas sobre Mudanças Climáticas Globais – Rede CLIMA, que temos o prazer de apresentar, reúne os objetivos e a organização do Programa, apresenta os destaques científicos do seu último ano, descreve sucintamente as suas dez sub-redes temáticas de pesquisa, e apresenta três novas sub-redes: Oceanos, Serviços Ambientais dos Ecossistemas e Desastres Naturais.

We examine potential critical thresholds for biome shift in the Amazonian tropical forest by forcing a potential vegetation model with prescribed climate anomalies and projections from global and regional climate models and different levels of CO2 fertilization effect under the SRES A2 scenario (2070-2099). The results indicate that tropical forests might be replaced by seasonal forests or savanna over eastern Amazonia with temperature increases of 2-3 degrees C (4-5 degrees C), when CO2 fertilization effect is not considered (partially considered), depending on precipitation anomaly. A precipitation decrease greater than 30% would trigger the shift from tropical forest to drier biomes, such as savanna and shrubland in southeastern Amazonia. The projected decrease in precipitation during the dry season and the increase of temperature are the main mechanisms driving calculated biome changes. However, biome changes are considerably smaller when the optimum fertilization effect is included.

This paper examines the constraints that limit the large-scale adoption of open source GIS. Although the open source GIS community has already achieved relevant results, their products have a small market share. There is equivalent to Linux and Apache in the open source GIS scene. We try to explain why this happens, by considering some factors that control the evolution and adoption of open source software. Our view is that the community effort is split in many different systems, not allowing a dominant solution to come forth. Thus, none of the current open source GIS has the potential to be a disruptive technology. Then, we consider a future scenario where most public geospatial data will be available as open access policy. This scenario is becoming more probable given recent data policy decision in Europe, USA and other countries. In this scenario, there is a major chance for a disruptive open source GIS to appear.

Forest to pasture conversion can lead to a decrease of precipitation induced by the decrease of evapotranspiration starting a positive feedback in the climate system. The accelerated deforestation rate suffered by Amazonian region is of global concern due to the importance of the Amazonia to the climate. Improve the understanding of the impact of deforestation in the hydrological cycle is of the highest importance. Nowadays, Amazonian landscape is no longer a homogeneous surface of pristine primary forest, but an heterogeneous irregular patches of pasture and agriculture plots of various sizes. Besides this, those patches were many times abandoned, creating opportunities for the regrowth of original vegetation (secondary forests). Impacts of fragmentation, and more specifically natural regrowth, on regional climate and hydrology are not well known. Previous studies pointed that the conversion of primary forest to pasture or agricultural crops affect the precipitation and runoff, and consequently evapotranspiration at micro scales, but this effect is not always detected at larger temporal and spatial scales. Few works suggested that the evaporative fraction of the secondary forest increases with the age of the forest in comparison with mature primary forests. Therefore, the objective of this study was to compare the evapotranspiration of one site of primary forest with one site of ~20 years old secondary forest in Central Amazonia, and to evaluate whether the secondary forest has a role on the resilience of the Amazon system compensating the effects of the deforestation on the water cycle. The latent heat flux of the secondary forest during the dry season was 29% higher than in the primary forest. During the wet season the secondary forest also presented 17% higher latent heat flux than in primary forest. The values of evapotranspiration were 4.28 mm day-1 for secondary forest against 3.32 mm day-1 for primary forest during the dry season, which represents a difference of around 1 mm day-1. During the wet season, the evapotranspiration for secondary forest was 3.99 mm day-1 against 3.42 mm.day-1 for primary forest, resulting in a difference of around 0.57 mm day-1. The evaporative fraction during the dry season in the secondary forest was around 0.80 and in the primary forest was 0.70. During the wet season this difference was lower, 0.89 for secondary forest and around 0.82 for primary forest. These results show that the difference on energy available for evapotranspiration is not the only cause of the higher evapotranspiration of the secondary forest in comparison with the primary forest in both dry and wet seasons. In conclusion, our study demonstrate that the secondary forest may play a relevant role in the Amazonia system, and confirm the urgent need of a better understanding of the role of this type of vegetation on a basin wide water and energy balance. Additionally, improvement of the representation of secondary vegetation on atmospheric models and in the analysis of soil-water-atmosphere interaction studies at regional and global scales.

A região do semi-árido nordestino brasileiro apresenta sérios problemas ambientais, entre os quais se destacam os processos de desertificação. Sendo assim, o objetivo deste estudo consiste em avaliar as mudanças de cobertura da terra em uma área de desertificação: o Núcleo de Desertificação de Gilbués, Estado do Piauí, Brasil. A análise engloba o período entre 1999 e 2009, e busca, além de avaliar as alterações ocorridas, identificar possíveis fatores do meio físico responsáveis pela dinâmica do processo de desertificação, como precipitação e pedologia. Para este estudo considerou-se imagens do satélite Landsat, sensores TM e ETM+, e estimativas de precipitação da plataforma TRMM (Tropical Raifall Measuring Mission). Além disso, foram utilizados mapas pedológicos, desenvolvidos pela EMBRAPA. A avaliação das alterações das classes de cobertura da terra mostrou que as áreas de cerrado sofreram uma redução de 9%, o equivalente a 550 km2 . O cerrado cedeu lugar às atividades agropecuárias e às áreas de desertificação, que sofreram um aumento de 5% (315 km2) e 4% (240 km2 ), respectivamente. As demais classes, como floresta perene, corpos dágua, área urbana e estradas permaneceram constantes. A precipitação na região variou entre 1.000 mm no setor sudeste e 1.300 mm no noroeste, concentradas essencialmente no verão, entre dezembro e fevereiro. Em relação à variabilidade interanual da precipitação, verificou-se que os eventos de secas ocorreram em anos de El Niño. O crescimento da classe agropecuária está associado às classes de precipitação no intervalo de 1100 a 1250 mm e com as áreas de ocorrência de Latossolo Amarelo. Observou-se associação entre a expansão da agropecuária e tipos de solo; no entanto, o mesmo não aconteceu com a precipitação. As áreas de solo exposto expandiram-se proporcionalmente de acordo com os intervalos de precipitação e com as classes de solos.