Cleiton da Silva Silveira

Forecasts of hydrological variables are extremely important for water resource management in regions that are particularly vulnerable to the effects of climate change and climate variability. The aim of this study was to develop a hybrid neural network capable of producing daily streamflow forecasts on a sub-seasonal scale. This hybrid neural network consists of an artificial neural network with inputs preprocessed by the wavelet transform (WANN). The WANN was tested in the Três Marias, Sobradinho, and Retiro Baixo reservoirs, located in the São Francisco River Basin (SFRB). The obtained results show that WANN was highly accurate in short-term forecasts (7–28 days); however, for long-term forecasts (35 and 42 days), there was a significant drop in performance, especially during the transition periods to the rainy season and in the dry months. The comparison between the performance metrics of the WANN forecasts and the National Electricity System Operator (ONS) operational models for the Três Marias, Sobradinho, and Retiro Baixo basins showed that WANN outperformed all these models. The results obtained show that WANN is a valuable tool for addressing the complex and dynamic challenges of hydrology, making it essential for decision-making on water resource management.

Study RegionGrande River Basin (GRB), Brazil, an important tributary of the São Francisco RiverStudy FocusEvaluate the impact of anthropogenic changes on the onset, development and recovery of hydrological droughts, considering different drought states and their transition probabilitiesNew hydrological insightsA new data-based method was proposed to evaluate the impact of anthropogenic changes on the evolution of hydrological drought called “Drought Roulette Analysis” (DRA). By applying the DRA in the GRB, it was possible to identify significantly slower hydrological recovery during the human-modified period, with increases in the probabilities of transitioning from hydrometeorological to hydrological drought (+5.68%) and of remaining in the hydrological drought state (+22.2%). The DRA provided greater flexibility for drought-propagation analysis in human-modified basins.

In this review, we examine dengue outbreak prediction and warning systems, highlighting their methodologies, variables, key findings, and existing gaps in the literature. The study was conducted in five stages: a literature survey, definition of thematic scope and eligibility criteria, exploratory review, systematization and categorization of findings, critical analysis, and comparative narrative synthesis. We selected 14 articles on prediction and seven on warning systems, encompassing statistical models, machine learning, and deep learning, as well as systems applied in various countries, with a particular focus on Brazil. The results indicated that meteorological and climatic variables are the most frequently used, followed by epidemiological and entomological data. Models such as Random Forest and Long Short-Term Memory demonstrated superior predictive performance, especially for short-term forecasts of up to 1 week. Among the warning systems, classical methods, such as the Early Aberration Reporting System, offer simplicity and speed but provide shorter lead times. In contrast, systems such as EWARS-TDR and ADSEWS excel by integrating multiple data sources and providing longer lead times (up to 13 weeks). Despite considerable advancements, challenges related to data quality and availability, model replicability across different contexts, and implementation persist in public health systems.

There is evidence that the climate on the planet has been undergoing variations over the years, resulting in climate events that are becoming increasingly extreme, such as heavy raining. The objective of this study was to verify the behavior and tendency of heavy rain in Brazil, and possible correlations with atmospheric temperature. The methodology utilizes Climate Extremes Indices (CEI), and the Mann-Kendall Test (MKT) and Sen’s Slope (SS) were applied in each of them to evaluate the statistical significance of the trends in climate extremes, as well as to measure the magnitudes, respectively. Then, Pearson’s Correlate Coefficient (PCC) between indexes was calculated. The total period of analysis was between 1991 to 2022. The MKT and SS results presented tendencies of extreme rain increase in the South, North, parts of the Northeast and Southeast coastline, and the decrease trend in the Midwest, Southeast and North. There are, too, increase trends in the maximum (TX) and minimum temperature (TN) in the whole country. PCCs were significant, between total/extreme rainfall and temperature, as follows: Northeast and Southeast (negative PCCs for TX); North and South (positive PCCs for TN). There are some areas where the SS and PCCs presented non-linear interdependence between these climatic variables. Therefore, the changes in the climate pattern can contribute to the increase trend in extreme precipitation events in different areas of Brazil.

Com objetivo de analisar a atuação dos egressos do curso de engenharia ambiental da Universidade Federal do Ceará (UFC), no mercado de trabalho e o seu alinhamento com as Diretrizes Curriculares Nacionais (DCNs) da engenharia, o presente documento exibe os resultados de uma pesquisa realizada com ex-estudantes desta graduação. A pesquisa apresentou três grandes etapas: aplicação e análise dos questionários com os egressos do curso; coleta dos trabalhos de conclusão do curso para posterior verificação das competências específicas e confronto com as respostas dos questionários; análises com base nos relatórios disponibilizados pelo ENADE. O espaço amostral foi de 214 egressos, considerando o intervalo de anos de 2014 a 2023, responderam a pesquisa 70 deles. Aproximadamente 85% estão exercendo algum tipo de atividade profissional. As competências específicas dispostas pelo NDE possuem correlação significativa com aquelas cobradas nas diretrizes de prova do Exame Nacional de Desempenho dos Estudantes (ENADE), e provavelmente com o desejado por parte do mercado de trabalho. Embora, a maioria dos egressos esteja inserido no mercado de trabalho na área ambiental, apenas 10% atua como engenheiro. Esse aspecto mostra a necessidade dos órgãos de fiscalização e regulamentação da profissão atuarem na verificação das atribuições e no respeito às leis que regem a profissão.

Background: Climate change projections impact dengue transmission in tropical regions, creating diverse and complex public health challenges. The aim of this study was to project future seasonal dengue incidence in a large tropical urban area of Brazil, where dengue is endemic, by systematically analyzing climatic and dengue case time series. Methods: An epidemiological dengue model was developed using time series analysis techniques and forced with statistical downscaling from various Coupled Model Intercomparison Project Phase 6 (CMIP6) climate models based on Shared Socioeconomic Pathway (SSP) scenarios for the late twenty-first century (2071–2100). The ecological time-series investigation analyzed 193 618 dengue cases from January 2008 to December 2018. Statistical downscaling transformed low-resolution Global Climate Models’ outputs into high-resolution data, based on a 30-y climate baseline. Results: The results indicated significant climate changes in seasonal temperature and precipitation by the end of the century. Under both SSP2-4.5 and SSP5-8.5 scenarios, substantial increases in dengue cases are projected during current low-incidence months, resulting in a reduced seasonality of dengue. Conclusions: The findings represent considerable challenges for future public health systems, which may face sustained high levels of dengue incidence throughout the year.

The present study addressed the effects of water scarcity on the deterioration of water quality in 155 reservoirs located in the state of Ceará, Brazil, using the drought index SPI (standardized precipitation index) calculated for the accumulation time scales of 3, 6, and 12 months. Based on this, a comparison was made with the variations in the trophic state index of these reservoirs, between 2008 and 2021. The study pointed to the occurrence of an intense series of dry events between 2012 and 2018, highlighting the year 2013, when the SPI assumed a value of -2.43 identifying an extremely dry year. Also, during this period, the amount of water stored by the state's reservoirs achieved only 8% of the total storage capacity, with the existence of eutrophic and hyper-eutrophic dams accounting for 68% of the total in 2016. In this context, it was observed that, during the transition from a dry to a wet period, the average trophic state index of the reservoirs tended to increase, rising from 62.1 (2008–2012) to 65.1 (2013–2017), before decreasing to 61.5 with the return of the wet period (2018–2021). In addition, to assess the influence of human activities on water quality, land use and occupation data from three basins in Ceará were analyzed. It was observed that the basin with the largest area occupied by agriculture experienced the most significant increases in total phosphorus and chlorophyll-a concentrations.

O presente artigo tem por objetivo apresentar um projeto de extensão universitária produzido na engenharia ambiental, o Jornal Gazeta Verde (JGV). Ativo desde 2023, o JGV tem como foco a educação ambiental e o fomento ao diálogo com a comunidade sobre questões socioambientais. Composta por uma equipe dedicada de estudantes de graduação, o projeto busca abordar e promover discussões sobre temas relevantes e atuais, utilizando uma linguagem acessível e informativa. O JGV publica uma edição escrita mensal, produzida por alunos e de livre acesso a todos, resumindo os principais eventos do mês relacionados a questões socioambientais, tecnologia e meio ambiente no Ceará, no Brasil e no mundo. O periódico também traz informações sobre temas relacionados à universidade, como pesquisas ambientais e questões estratégicas relativas aos cursos da UFC (por exemplo, uma coluna dedicada aos egressos intitulada "Por onde anda"). Também oferece críticas joviais e bem-humoradas por meio do quadro artístico "Ambiart". Além disso, o jornal se estende além dos limites da universidade, alcançando periferias, praias e bairros para ouvir as perspectivas da comunidade sobre questões socioambientais. Esse esforço de divulgação contribui para a produção de conteúdo (vídeos e fotos) para mídias sociais e para o site de hospedagem do periódico. Os indicadores de resultados incluem: edições de leitura mensais; regularidade na produção e disseminação de conteúdo; conteúdo exclusivo audiovisual, dentre outros. O JGV tem se mostrado um instrumento importante de formação dos estudantes (especialmente no desenvolvimento das “soft skills”) e de escuta da comunidade.

The occurrence of subseasonal phenomena, such as dry spells and flash droughts, are potentially detrimental to the agricultural sector and water resources. The impacts on agricultural sector have been well explored by the technical-scientific community, attesting to the importance of subseasonal variability for this sector, especially for low-tech farming areas. However, when it comes to water resources, there is a large gap regarding the hydrological impacts of these phenomena, in a way that pertinent questions about the importance of subseasonal variability for water resources management remain still unexplored or poorly understood. This study evaluated the impacts of dry spells on reservoir inflow in semiarid regions, taking the Orós reservoir (Northeast Brazil) as a case study. The relationship between the dry spell index and the inflow of Orós reservoir during the rainy season was analyzed, as well as the daily time series of precipitation and storage volume during two long-term dry spells. The two formulated hypotheses suggest that dry spells are indeed capable of reducing the reservoir inflow efficiency in semiarid regions during rainy seasons. These hypotheses serve as a starting point for a deeper discussion on the impacts of dry spells on water resource management in arid and semiarid regions.