Publicações

Resumo: A Mata Atlântica é um dos biomas brasileiros onde a partição das chuvas é mais estudada. No entanto, a maior parte das pesquisas é de curta duração, raramente ultrapassando um ano de coleta de dados. Investigações de longo prazo são importantes para avaliar a variação interanual desse processo hidrológico. O presente estudo teve como objetivo a quantificação da transprecipitação e a estimativa da interceptação das chuvas pelas copas das árvores na microbacia experimental B, recoberta com Floresta Ombrófila Densa Altomontana, no Laboratório de Hidrologia Florestal Walter Emmerich, Cunha-SP. Para esse propósito foi realizado o monitoramento da precipitação no aberto e da transprecipitação ao longo de três anos e 11 meses. Para a determinação da transprecipitação foram utilizados dez coletores (pluviômetros) de polietileno (galão e funil). Em uma parcela delimitada sob a floresta foram instalados trinta e seis suportes para acomodar os coletores. Semanalmente foram sorteados dez pontos diferentes onde eram instalados os coletores. A precipitação no aberto foi obtida por um dispositivo idêntico aos de transprecipitação e por três pluviógrafos localizados em área aberta da microbacia. A interceptação foi estimada pela diferença entre a precipitação no aberto e a transprecipitação média na parcela. Os resultados mostraram elevada variação interanual dos percentuais da transprecipitação e da interceptação em relação à precipitação no aberto, com valores variando entre 67% e 87% e 13% e 33%, respectivamente. Os percentuais de transprecipitação foram maiores no período chuvoso que no período pouco chuvoso, com valores médios de 78% e 68%, respectivamente. A interceptação, ao contrário, teve os maiores percentuais na estação pouco chuvosa (33%) que na chuvosa (22%). Regressões lineares simples correlacionando a transprecipitação e a precipitação no aberto apresentaram bom ajuste, com coeficiente de determinação superior a 91%, ao contrário das equações relacionando a interceptação com a precipitação no aberto, cujos coeficientes de determinação variaram de 9,2% a 66,1%.

ABSTRACT: The Atlantic Forest is one of the Brazilian biomes where the rainfall partitioning process is more studied. However, most research is short, rarely exceeding one year of data collection. Long-term research is needed to assess the interannual variation of this hydrological process. This study aimed to quantify the throughfall and interception of rain by canopy in the experimental catchment “B” covered with Dense Ombrophilous Forest, in the Walter Emmerich Forest Hydrological Laboratory, CunhaBrazil. For this purpose, monitoring of gross precipitation and throughfall over three years and 11 months was conducted. For the determination of the throughfall ten polyethylene containers were used in which plastic funnels were attached. In a plot delimited under the forest were installed thirty-six supports to accommodate the collectors. Ten different points were randomly drawn ten times by the generation of ten random numbers from 1 to 36 where the collectors were installed. The gross precipitation was obtained by a device similar to those of throughfall and the records of three tipping bucket rain gauges installed in clearing in the interior of the watershed. The interception was estimated by the difference between the gross precipitation and the mean throughfall in the plot. The results showed large annual variation in the percentage of throughfall and interception in relation to gross precipitation, with extreme values of 67% to 87% and 13% to 33% respectively. The percentage of throughfall were higher in the rainy season (October to March) that the little rainy season (April to September), with average values of 78% and 68%, respectively. The interception, by contrast, had the highest percentages in little rainy season (33%) than in the wet (22%). Simple linear regressions established between throughfall and gross precipitation in the annual open showed very good fit, with a coefficient of determination higher than 91%, unlike the equations relating the interception with gross precipitation, whose determination coefficients ranged from 9.2% to 66.1%.

RESUMEN: La Mata Atlántica es uno de los biomas brasileños donde la partición de las lluvias es más estudiada. Sin embargo, la mayoría de las investigaciones son de corta duración, rara vez superando un año de recolección de datos. Las investigaciones a largo plazo son importantes para evaluar la variación interanual de este proceso hidrológico. El presente estudio tuvo como objetivo la cuantificación de la precipitación de copas y la estimación de la interceptación de precipitación por las copas de los árboles en la microcuenca experimental B, recubierta con Bosque Ombrófilo Denso, en el Laboratorio de Hidrología Forestal Walter Emmerich, Cunha-Brasil. Para ese propósito se realizó el monitoreo de la precipitación bruta y de la precipitación de copas a lo largo de tres años y 11 meses. Para la determinación de la precipitación de copas se utilizaron diez contenedores de polietileno en los que se unieron embudos de plástico. En una parcela delimitada bajo el bosque se instalaron treinta y seis soportes para acomodar a los colectores. Diez puntos diferentes fueron dibujados al azar diez veces por la generación de diez números aleatorios del 1 al 36 donde se instalaron los colectores. La precipitación bruta fue obtenida por un dispositivo idéntico a los de precipitación de copas y los registros de tres pluviómetros de cubeta basculante instalados en claros en el interior de la cuenca. La intercepción se estimó por la diferencia entre la precipitación bruta y precipitación de copas media en la parcela. Los resultados mostraron gran variación interanual de los porcentajes de la precipitación de copas y de la interceptación en relación a la precipitación bruta, con valores extremos de 67% y 87% y 13% y 33%, respectivamente. Los porcentajes de precipitación de copas fueron mayores en el período lluvioso que en el período poco lluvioso, con valores medios de 78% y 68%, respectivamente. La interceptación, por el contrario, tuvo los mayores porcentuales en la estación poco lluviosa (33%) que en la lluviosa (22%). Las regresiones lineales simples correlacionando la precipitación de copas y la precipitación bruta presentaron muy buen ajuste, con coeficiente de determinación superior al 91%, al contrario de las ecuaciones relacionando la interceptación con la precipitación bruta, cuyos coeficientes de determinación variaron del 9,2% a 66 1%.

RESUME: La forêt atlantique est l’un des biomes brésiliens où la répartition des précipitations est plus étudiée. Cependant, la plupart des enquêtes sont de courte durée, dépassant rarement une année de collecte de données. Des études à long terme sont importantes pour évaluer la variation interannuelle de ce processus hydrologique. Cette étude visait à quantifier les pluviométrie au sol et une interception estimée de la cime des arbres de la pluie dans le bassin versant expérimental B, couvert de Forêt Tropicale Dense, le Laboratoire d’Hydrologie Forestière Walter Emmerich, Cunha-Brésil. A cet effet, a été suivi de la pluie incidente et pluviométrie au sol sur trois ans et 11 mois. La pluie incidente a été obtenue par la mesure dun pluviomètre et par lenregistrement de trois pluviomètres à auget basculeur installés dans des brèches à lintérieur du bassin versant. Pour la détermination du pluviométrie au sol, on a utilisé dix récipients en polyéthylène dans lesquels des entonnoirs en plastique étaient fixés. Sur une parcelle délimitée sous la forêt, trente-six supports ont été installés pour accueillir les collecteurs. Dix points différents ont été tirés au sort dix fois au hasard par la génération de dix nombres aléatoires de 1 à 36 où les collecteurs ont été installés. L’interception a été estimée par la différence entre La pluie incidente et le pluviométrie au sol dans la parcelle. Les résultats ont montré une grande variation annuelle du pourcentage de pluviométrie au sol et l’interception par rapport à la pluie incidente, avec des valeurs de 67% et 87% et 13% et 33%, respectivement. Les pourcentages étaient plus élevés dans des pluies période de bit pluviométrie au sol en saison des pluies avec des valeurs moyennes de 78% et 68%, respectivement. L’interception, en revanche, avaient les pourcentages les plus élevés en saison des pluies peu (33%) que dans l’humide (22%). La régression linéaire simple corrélation pluviométrie au sol et les pluie incidente a montré une très bonne forme, avec un coefficient de détermination dépassant 91%, à la différence des équations relatives à l’interception avec des pluie incidente, dont les coefficients de corrélation variaient de 9,2% à 66,1%.

Under the United Nations Framework Convention on Climate Change, the Clean Development Mechanism (CDM) requires local stakeholders to participate by sharing their comments on CDM activities. This stipulation aims at promoting social equity, a key element of sustainable development. We draw on the stakeholder theory to examine the local stakeholder participatory process in CDM in four Latin American countries Brazil, Honduras, Mexico, and Peru. We analyze 625 projects using cluster analysis and multidimensional scaling. The results confirm that in countries that have put in place national procedures for stakeholder consultation, such as Brazil and Peru, the role of national institutions is highlighted. Conversely, in countries with no national government guidelines on local stakeholder participation, such as Honduras and Mexico, private companies dominate the local stakeholder consultation process. In all the four countries, we identify a lack of community involvement in discussions and deliberations on the potential benefits of CDM projects, and a lack of participatory decision-making mechanisms. The projects we analyzed demonstrate that companies use stakeholder participation concept merely as a rhetoric tool to legitimate company activities, ostensibly to create value for all involved, but in practice providing almost no participation to the local communities. The findings also suggest the importance of national legal requirements in ensuring broad engagement at the local level. The stakeholder model established for CDM can be improved in the new market mechanism under the Paris Agreement by empowering local authorities and by formulating guidelines in domestic legal provisions for participatory processes.

Mapping forest types and tree species at regional scales to provide information for ecologists and forest managers is a new challenge for the remote sensing community. Here, we assess the potential of a U-net convolutional network, a recent deep learning algorithm, to identify and segment (1) natural forests and eucalyptus plantations, and (2) an indicator of forest disturbance, the tree species Cecropia hololeuca, in very high resolution images (0.3 m) from the WorldView-3 satellite in the Brazilian Atlantic rainforest region. The networks for forest types and Cecropia trees were trained with 7611 and 1568 red-greenblue (RGB) images, respectively, and their dense labeled masks. Eighty per cent of the images were used for training and 20% for validation. The U-net network segmented forest types with an overall accuracy >95% and an intersection over union (IoU) of 0.96. For C. hololeuca, the overall accuracy was 97% and the IoU was 0.86. The predictions were produced over a 1600 km2 region using WorldView-3 RGB bands pan-sharpened at 0.3 m. Natural and eucalyptus forests compose 79 and 21% of the regions total forest cover (82 250 ha). Cecropia crowns covered 1% of the natural forest canopy. An index to describe the level of disturbance of the natural forest fragments based on the spatial distribution of Cecropia trees was developed. Our work demonstrates how a deep learning algorithm can support applications such as vegetation, tree species distributions and disturbance mapping on a regional scale.

O objetivo deste artigo é contribuir com o debate acerca do desmatamento no contexto da evolução das políticas de gestão fundiária e territorial na Amazônia, destacando seu papel relevante para o reconhecimento de direitos políticos de categorias sociais minoritárias. A associação do desmatamento na Amazônia sempre esteve correlacionada a problemas sociais e envolve diferentes agentes e fatores causadores conforme a área de abrangência e o momento de sua realização. Procuram-se evidenciar alguns dos principais fatores institucionais que contribuem para pôr em xeque as conquistas do modelo socioambiental por meio de um estudo de caso no assentamento rural categoria Projeto Agroextrativista Praialta-Piranheira, Pará. Essa análise permite concluir que a falta de coerência institucional representa um aspecto estrutural cujo desconhecimento incapacita a compreensão das dinâmicas territoriais da Amazônia.

Disturbance of vegetation is a critical component of land cover, but is generally poorly constrained in land surface and carbon cycle models. In particular, land-use change and fire can be treated as large-scale disturbances without full representation of their underlying complexities and interactions. Here we describe developments to the land surface model JULES (Joint UK Land Environment Simulator) to represent land-use change and fire as distinct processes which interact with simulated vegetation dynamics. We couple the fire model INFERNO (INteractive Fire and Emission algoRithm for Natural envirOnments) to dynamic vegetation within JULES and use the HYDE (History Database of the Global Environment) land cover dataset to analyse the impact of land-use change on the simulation of present day vegetation. We evaluate the inclusion of land use and fire disturbance against standard benchmarks. Using the Manhattan metric, results show improved simulation of vegetation cover across all observed datasets. Overall, disturbance improves the simulation of vegetation cover by 35% compared to vegetation continuous field (VCF) observations from MODIS and 13% compared to the Climate Change Initiative (CCI) from the ESA. Biases in grass extent are reduced from -66% to 13 %. Total woody cover improves by 55% compared to VCF and 20% compared to CCI from a reduction in forest extent in the tropics, although simulated tree cover is now too sparse in some areas. Explicitly modelling fire and land use generally decreases tree and shrub cover and increases grasses. The results show that the disturbances provide important contributions to the realistic modelling of vegetation on a global scale, although in some areas fire and land use together result in too much disturbance. This work provides a substantial contribution towards representing the full complexity and interactions between land-use change and fire that could be used in Earth system models.

O Acordo de Paris é um tratado global, adotado em dezembro de 2015 pelos países signatários da Convenção-Quadro das Nações Unidas sobre Mudança do Clima (UNFCCC, acrônimo em inglês), durante a 21ª Conferência das Partes (COP21). Esse acordo rege medidas de redução de emissão de dióxido de carbono a partir de 2020, e tem por objetivos fortalecer a resposta à ameaça da mudança do clima e reforçar a capacidade dos países para lidar com os impactos gerados por essa mudança. Por meio deste acordo, os governos se comprometeram em agir para manter o aumento da temperatura média mundial “bem abaixo” dos 2 °C em relação aos níveis pré-industriais e em envidar esforços para limitar o aumento a 1,5 °C. Para tanto, os países apresentaram planos de ação nacionais abrangentes para reduzirem as suas emissões por meio da formulação de sua Contribuição Nacionalmente Determinada (NDC, acrônimo em inglês). O governo brasileiro comprometeu-se em sua NDC a reduzir as emissões de gases de efeito estufa em 37% em 2025, com uma contribuição indicativa subsequente de redução de 43% em 2030, em relação aos níveis de emissões estimados para 2005. Com intuito de contribuir com a ampla divulgação do Acordo de Paris, o Ministério da Ciência, Tecnologia, Inovações e Comunicações, editou esse encarte que contempla a versão oficial do Governo Brasileiro (Decreto no 9.073/2017) para o acordo, em português, e a versão original, em inglês, da UNFCCC (Anexo da Decisão 1/CP.21).

Aedes aegypti has developed evolution-driven adaptations for surviving in the domestic human habitat. Several trap models have been designed considering these strategies and tested for monitoring this efficient vector of Dengue. Here, we report a real-scale evaluation of a system for monitoring and controlling mosquito populations based on egg sampling coupled with geographic information systems technology. The SMCP-Aedes, a system based on open technology and open data standards, was set up from March/2008 to October/2011 as a pilot trial in two sites of Pernambuco Brazil: Ipojuca (10,000 residents) and Santa Cruz (83,000), in a joint effort of health authorities and staff, and a network of scientists providing scientific support. A widespread infestation by Aedes was found in both sites in 2008-2009, with 96.8\%-100\% trap positivity. Egg densities were markedly higher in SCC than in Ipojuca. A 90\% decrease in egg density was recorded in SCC after two years of sustained control pressure imposed by suppression of >7,500,000 eggs and >3,200 adults, plus larval control by adding fishes to cisterns. In Ipojuca, 1.1 million mosquito eggs were suppressed and a 77\% reduction in egg density was achieved. This study aimed at assessing the applicability of a system using GIS and spatial statistic analysis tools for quantitative assessment of mosquito populations. It also provided useful information on the requirements for reducing well-established mosquito populations. Results from two cities led us to conclude that the success in markedly reducing an Aedes population required the appropriate choice of control measures for sustained mass elimination guided by a user-friendly mosquito surveillance system. The system was able to support interventional decisions and to assess the program’s success. Additionally, it created a stimulating environment for health staff and residents, which had a positive impact on their commitment to the dengue control program.

Most energy generation globally is fueled by coal and oil, raising concerns about greenhouse gas emissions. Hydroelectric reservoirs are anthropogenic aquatic systems that occur across a wide geographical extent, and, in addition to their importance for energy production, they have the potential to release two important greenhouse gases (GHGs), carbon dioxide and methane. We report results from an extensive study of eight hydroelectric reservoirs located in central and southeastern tropical Brazil. In the Brazilian dry tropical biome reservoirs, emissions (in tons of CO2 Eq. per MW h) varied from 0.01 to 0.55, and decreased with reservoir age. Total emissions were higher in the reservoir lake when compared to the river downstream the dam; however, emissions per unit area, in the first kilometer of the river after the dam, were higher than that in the reservoir. The results showed, despite higher carbon emissions per energy production in the youngest reservoirs, lower emission from hydroelectric reservoirs from the studied region in relation to thermo electrical supply, fueled by coal or fossil fuel. The ratio emission of GHG per MWh produced is an important parameter in evaluating the service provided by hydroelectric reservoir and for energy planning policies.