Publicações

Soil moisture information is essential to monitoring of the intensity of droughts,the start of the rainy season, planting dates and early warnings of yield losses.We assess spatial and temporal trends of drought over the Brazilian semiaridregion by combining soil moisture observations from 360 stations, root zone soilmoisture from a leading land surface model, and a vegetation health index fromremote sensing. The soil moisture dataset was obtained from the network of sta-tions maintained by the National Center of Monitoring and Early Warning ofNatural Disasters (Cemaden), in Brazil. Soil water content at 10 to 35 cm depth,for the period 19792018, was obtained from running the JULES land surfacemodel (the Joint UK Land Environment Simulator). The modelled soil moisturewas correlated with measurements in the common period of 20152018, result-ing in an average correlation coefficient of 0.48 across the domain. The standard-izedsoilmoistureanomaly(SMA)wascalculatedforthelong-termmodelledsoilmoisture and revealed strong negative values during well-known drought peri-ods in the region, especially during El-Niño years. The performance of SMA inidentifying droughts during the first 2 months of the raining and cropping sea-son was similar to the Standardized Precipitation Index (SPI), commonly usedfor drought assessment: 1214 events were identified by both indices. Finally, thetemporal relationship between both SMA and SPI with the Vegetation HealthIndex (VHI) was assessed using the cross-wavelet transform. The results indi-cated lagged correlations of 1 to 1.5 months in the annual scale, suggesting thatnegative trends in SMA and SPI can be an early warning to yield losses during the growing season. Public policies on drought assessment should consider thecombination of multiple drought indices, including soil moisture anomaly. 

Este artigo apresenta uma análise sobre o processo formativo de um grupo de atores interessados na temática da Gestão dos Recursos Hídricos no estado de São Paulo, em especial, na Bacia do Paraíba do Sul. Tem como conceitos orientadores a pedagogia da práxise a ciência cidadã. A metodologia é qualitativa e fundamenta-se emdiferentes estratégias de pesquisa de campo. O intuito maior, além de analisar o processo formativo, éverificar a alteração da percepção ambiental dos atores participantes de umcurso. Conclui-se que a experiência formativa oferecida pelo curso, fundada em metodologias participativas, produz efeitos positivos no engajamento dos atores envolvidos nos territórios de interesse. ABSTRACT: This article presents an analysis of the learningprocess of a group of actors interested in the theme of Water Resources Management in the State of São Paulo, especially in the Paraíba do Sul Basin. Its guiding concepts are the pedagogy of praxis and citizen science. The methodology is qualitative and isbased on different field research strategies. The main purpose, in addition to analyzing the learningprocess, was to verify the change in the environmental perception ofthe actors participating in the course. The conclusion isthat the educationalexperience offered by the course, based on participatory methodologies, produces positive effects in the engagement of actors involved in the territories of interest. 

Há importantes lacunas metodológicas para se analisar devidamente os impactos cumulativos de um conjunto de empreendimentos, considerando as complexidades e interações entre os impactos. Esse é o caso de aproveitamentos hidrelétricos, os quais afetam funções ecossistêmicas de forma significativa, especialmente quando em cascata. Assim, o presente trabalho propõe uma abordagem metodológica para analisar os impactos cumulativos de Pequenas Centrais Hidrelétricas (PCHs) em cascata na fase de operação pela perspectiva dos sistemas socioecológicos e analisa as mudanças de uso e cobertura da terra de sete PCHs na sub-bacia Guaporé no estado de Rondônia. Foram utilizadas as classificações do MapBiomas, considerando um buffer de 50km linear aos rios Branco e Saldanha para 3 períodos: início da operação da primeira PCH (1999); último ano disponível do MapBiomas, quando todas as PCHs estão em operação (2020); e ano intermediário (2011), quando a quarta PCH entrou em operação. A formação florestal apresentou perdas sucessivas (total de 3.393 km²), com maiores perdas entre 1999 e 2011. A maior parte dessa cobertura vegetal se converteu em pastagem e agricultura anual, classes que tiveram maior aumento de 1999 a 2020. As demais classes tiveram pouca variação em porcentagem e área. Portanto, observou-se que as mudanças de uso e cobertura da terra podem representar um testemunho relevante das diversas alterações ecossistêmicas causadas por PCHs em cascata em distintos intervalos de tempo, podendo se revelar uma abordagem para a avaliação de impactos cumulativos.

The Food-Water-Energy (FWE) nexus represents, above all, a perspective, a way of looking at the world, the problems, the solutions, providing a view of the three main resource systems of food, water and energy, not in isolation, but as a system, with many and diverse cross-links between the subsystems. So, analytically speaking, it is a unifying concept, an antidote to the relentless pressures towards reductionism. Human society and its interactions with the natural environment form a dynamic socio-ecological system of such impressive complexity that reductionist approaches seem inevitable to make research and management on the subject viable. This development is not just an illusion – this book already presents some real examples of inter and transdisciplinary approaches, with the FWE nexus as a shared lens to better observe where problems occur and where sustainable solutions can be found.

In this chapter, we examine the main components of greenhouse gas budgets from tropical terrestrial and aquatic environments, including how these components are measured and modeled at scales ranging from field plots to regions. We discuss uncertainties associated with measurements and models, review the most current knowledge, and present efforts underway to further advance our knowledge of the tropic greenhouse gas budget. 

As turfeiras armazenam grande quantidade de carbono (C) e têm atuado como sumidouros de CO2 atmosférico, mas também podem se comportar como importantes fontes de Gases de Efeito Estufa (GEE) para a atmosfera (CO2, CH4 e N2O) quando submetidas a drenagem e mudança no seu uso alterando a cobertura da terra. Quantificar os estoques de carbono em turfeiras, bem como os parâmetros que regulam a dinâmica de C e também do nitrogênio (N) é essencial para subsidiar políticas públicas que visem a proteção desses ecossistemas. Este estudo teve como objetivo avaliar o efeito da mudança do uso e da cobertura da terra na dinâmica do carbono e nitrogênio em turfeiras na várzea do Rio Paraíba do Sul, considerando as coberturas da terra, bem como a análise temporal feita em cronossequência. Coleta de amostras de solo e de ar foram realizadas em 24 locais entre 2019 e 2020 nas estações secas e chuvosas bem como na transição entre elas. Os fluxos foram medidos utilizando-se câmaras estáticas de PVC com coletas de amostras em períodos de 30 minutos, em solos cobertos por florestas, pastagens e agricultura e em áreas >10 anos e <10 anos. Os resultados evidenciam solos orgânicos, altamente ácidos (pH <4,3) e de alta densidade 0,87 g/cm³), com teor de matéria orgânica por volta de 39%. Concentrações elevadas de macro e micronutrientes foram observadas na região, especialmente nitrogênio (média 0,47%), Fe (média 266,67 mg/kg) e Ca (média de 640,47mg/kg), associadas principalmente à deposição seca e ao manejo agrícola. Os resultados mostram fluxo médio de (1660,79 ± 1729,86) g m-2 ano-1 de CO2 , (0,30 ± 1,41) g m-2 ano-1 de CH4 e (0,45 ± 0,9) g m-2 ano-1 de N2O, não apresentando diferenças significativas entre as coberturas do solo nem mesmo nas cronossequências adotadas. Os resultados indicaram que, neste ecossistema, as emissões foram reguladas por características químicas e físicas do solo, principalmente a profundidade do nível freático que regulou os níveis de saturação do solo. Os fluxos de CO2 foram maiores quando o nível freático atingiu 1,5 metros de profundidade e menores quando atingiu a superfície do solo, favorecendo a emissão de CH4. O estoque de carbono acumulado nas camadas de 0-20cm variou entre 159,2 e 470,5 Mg C ha-1, totalizando 482 Tg de C e a decomposição da matéria orgânica do solo promoveu a perda média de carbono de 1164,63 GgCO2eq.ano-1 (variação entre -52,20 e 7458,21 GgCO2eq.ano-1) representando valores até 5,4% das emissões totais no estado de São Paulo, evidenciando que as turfeiras são fontes significativas de GEE e devem ser consideradas nos inventários regionais. Assim, fica evidente que aprofundar o entendimento da dinâmica do carbono e do nitrogênio, bem como dos parâmetros que regulam as emissões de GEE, nestes solos, são de extrema importância na conservação dos estoques de carbono na região.

A pesquisa presente iniciação científica foi iniciada em abril de 2021 e tem por objetivo o diagnóstico do tema das mudanças climáticas em espaços educadores, de forma a identificar barreiras e oportunidades para alavancar o tema das mudanças climáticas dentro de políticas públicas e estratégias de educação ambiental, considerando a dimensão pedagógica. As análises foram realizadas a partir de abordagens bibliométricas. O projeto tem as seguintes referenciais teóricos: políticas públicas de educação ambiental, mudanças do clima, antropoceno, transição para a sustentabilidade e objetivos do desenvolvimento sustentável (ODS). O desenho metodológico prevê o levantamento de dados em bases científicas, com foco na plataforma Scopus, sistematização dos dados e análises quantitativas. Os resultados indicam que, embora haja um evidente crescimento da produção científica que considere a dimensão da educação ambiental dentro do escopo dos termos descritos (mudanças climáticas, antropoceno, transição para a sustentabilidade e ODS), em valores totais essa produção é muito tímida frente a outras possíveis dimensões de análise, principalmente aquelas ligadas às ciências naturais e exatas.

The Pantanal region in South America is one of the worlds largest wetlands. Since 2019, the Pantanal has suffered a prolonged drought that has spelled disaster for the region, and subsequent fires have engulfed hundreds of thousands of hectares, and this situation has worsened in 2021. The lack of rainfall which affected the region during the summers of 2019, 2020 and 2021 was caused by a dual effect, namely I) the reduced transport of warm and humid summer air from Amazonia into the Pantanal; and II) the predominance of warmer and drier air masses from subtropical latitudes, which contributed to a scarcity of summer rainfall at the peak of the monsoon season. This led to prolonged extreme drought conditions across the region which had severe impacts on the hydrology of the Pantanal. Hydrometric levels fell significantly in 2020 all along the Paraguay River and have not yet recovered. In addition, three intense heat waves struck the region in spring 2020 resulting in record-breaking daily maximum temperatures in several locations in central South America. Several localities reported maximum temperatures above 40 ºC for several days in a row, and temperature anomalies of 10 ºC. This sequence of heat waves aggravated the drought over the Pantanal and nearby regions (including Bolivia). Overall, this superposition of major heat waves and intense droughtncreased dramatically the number of large wildfires, with serious impacts on the ecosystems and socioeconomic activities in the area. Due to these compound dry and hot conditions, fires spread and affected natural biodiversity as well as the agribusiness and cattle ranching sectors. Based on satellite data from MODIS we conclude that the total burned area in Pantanal in 2020 has increased by 376% when compared to the average of 2003-2019, and 43% of the area affected in 2020 had not been burnt previously in 2003-2019. The area affected by fire in the Brazilian Pantanal at the end of September 2021 (1,089,975ha) is very above the historical average (616,125 ha). However, differently from 2020, when fires reached the northern part of Pantanal, in 2021 the most critical region affected was the southern part. It should be stressed that, despite the level of dryness and high temperature observed recently, these last three years do not represent an outlier but more the culmination of highly significant trends towards a much drier and hotter climate. This vicious cycle of drought and extreme heath is consistent with what is expected under a warming climate, with higher risks of fire and water crises in the region.

The Suns radiation is the primary energy source for chemical, biological, and physical processes that happen in the climate system. Thus, the earth-atmosphere radiative balance system is one of the main aspects of climate change. Natural fluctuations in incident solar radiation caused by the sunspot cycle can influence the energy balance. In addition, human activities can also affect this balance. Changes in gases and aerosols emissions to the atmosphere can modify its composition because they are involved in complex chemical reactions, such as ozone concentrations. Gases and aerosols are able to absorb, scatter and reflect incident solar radiation, thereby affecting the balance. This study assesses the direct impact of aerosol (through changing the optical depth of aerosol-AOD in the radiation subroutine) on the surface atmospheric temperature and radiation balance. Three simple experiments for 1998-2017 were carried out through numerical modeling using BAM-v1.2 (Brazilian Global Atmospheric Model), the operational weather and climate forecasting model at CPTEC/INPE (Center for Weather Forecasting and Climate Studies/National Institute for Space Research).These experiments were zero aerosols, fixed AOD over the land and ocean, and AOD climatology with a spatial and temporal variation (AOD-C). The surface atmospheric temperature was validated against the ERA5 reanalysis from December to February (DJF) and June to August (JJA). Also, the downward shortwave solar radiation on the clear-sky variable was validated against CERES-EBAF satellite data. We performed the bias, the difference between the model and the reanalysis data (ERA5) and EBAF-CERES, correlation and RMSE of the model results against ERA5 and EBAF-CERES for surface temperature and downward shortwave solar radiation on clear-sky respectively.Our results have shown a positive bias atmospheric surface temperature for the northern hemisphere continent and a contrary, negative bias for the southern hemisphere continent during JJA. We observed a decrease in this positive bias in the northern hemisphere in the experiments with fixed aerosols, but an important improvement (vies, correlation, and RMSE) was observed in the experiment with AOD-C. On the other hand, during the DJF period, the model has a positive bias only in some continental areas, such as southwestern South America and South Africa, North Africa, and the Australian continent. Similarly, to JJA we observed improvements in these regions in the experiments that use fixed and AOD-C.The downward shortwave solar radiation on clear-sky results for both DJF and JJA showed an inversion from the positive bias to a negative bias in the model version without aerosols to the model versions with fixed aerosols and AOD-C, due to the presence of the aerosol, which reduces short wave flow. An important improvement (vies, correlation, and RMSE) in the downward shortwave solar clear sky was observed in the version that uses AOD-C during JJA.

Land use and land cover (LULC) changes strongly affect local hydrology and sediment yields. The current study focused on a basin in the Brazilian Amazon and had the following three objectives: (1) to perform an effective diagnosis of flow and sediment yield, (2) to evaluate the impacts of LULC changes over the last 40 years on the hydro-sedimentological variables, and (3) to investigate the impacts of the possible trends or breaking points in the flow, surface runoff, and sediment yield series. The Soil and Water Assessment Tool (SWAT) model validation showed that the simulated results were consistent with the data measured in the dynamic reproduction of flow seasonality. Furthermore, changes in LULC altered surface runoff, sediment yield, and flow according to the Mann-Kendall and Pettitt non-parametric tests. It was also observed that the sub-basins in which pastureland is predominant are more susceptible to increased surface runoff and sediment yield. According to trend and homogeneity tests, these sub-basins had break points in the time series of these variables. On the other hand, in the sub-basins whose land cover is predominantly forest, the time series is homogeneous and trendless. The current study highlighted the impacts that 40 years of LULC changes in an Amazonian basin had on hydro-sedimentological variables, which, in turn, can play an important role in changing the hydrological cycle, consequently these changes can also impact diverse human activities in the region, such as agribusiness, livestock, energy production, food security, and public water supply. Thus, it is concluded that the SWAT model is a good estimator of hydro-sedimentological processes in Amazonian basins and can be used by decision makers in the management of water and environmental resources.