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  1. Abstract

    While there have been efforts to supply off-grid energy in the Amazon, these attempts have focused on low upfront costs and deployment rates. These “get-energy-quick” methods have almost solely adopted diesel generators, ignoring the environmental and social risks associated with the known noise and pollution of combustion engines. Alternatively, it is recommended, herein, to supply off-grid needs with renewable, distributed microgrids comprised of photovoltaics (PV) and in-stream generators (ISG). Utilization of a hybrid combination of renewable generators can provide an energetically, environmentally, and financially feasible alternative to typical electrification methods, depending on available solar irradiation and riverine characteristics, that with community engagement allows for a participatory codesign process that takes into consideration people’s needs. A convergent solution development framework that includes designers—a team of social scientists, engineers, and communication specialists—and communities as well as the local industry is examined here, by which the future negative impacts at the human–machine–environment nexus can be minimized by iterative, continuous interaction between these key actors.

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  2. Abstract

    Hydropower dams have received increased global attention due to their detrimental socioenvironmental ramifications. Such attention has led to an increase in studies on the impacts of reservoir operation on river flow; however, a holistic understanding of the compounded effects of hydropower dams on different hydrological characteristics is lacking, especially for large river basins such as the Amazon where hydropower development is on the rise. Here, we mechanistically quantify the historical impacts of existing dams and the potential impacts of the collective operation of existing and planned dams on a basin‐wide scale in the Amazon for the 1981–2019 period. We build on the recently developed high‐resolution (3‐arcmin; ∼5 km) river‐floodplain‐reservoir model, the CaMa‐Flood‐Dam, which is enhanced to realistically simulate hydropower dam operation considering maximized power production. Flood simulations are further downscaled to 3 arc‐seconds (∼90 m) resolution to investigate the impacts of dams on fine‐scale flood dynamics across the basin. Results indicate that existing dams have substantially altered downstream river flow and flooding patterns across the Amazon River basin. Specifically, large dams in the Amazonian subbasins, including the Xingu, Madeira, and Tocantins, have altered downstream river flow amplitude by up to 3 orders of magnitude. Further, the collective operation of existing and planned dams could increasingly alter river flow patterns, causing ∼10% decrease in flood duration in many parts of the Amazon mainstem. Our results provide quantitative evidence on the severity of the hydrologic impacts of large hydropower dams and have important implications for sustainable hydropower operation and development in the Amazon and worldwide.

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  3. Abstract

    Nations in the global South have developed hydropower projects at a rapid pace in recent decades, most notably Brazil and China. These projects have long‐documented impacts on social and ecological systems, yet the implications of hydropower for human well‐being and health are not fully understood. In this paper, we examine eight Brazilian Amazon communities in the Madeira river basin, near the Jirau and Santo Antônio dams (sample size: 536 households). We evaluate how impacts on community resources, social capital, and the experience of resettlement influence self‐rated health in these communities. Results suggest that the dams strained community resources and social capital, which were associated with reductions in self‐rated health. In particular, cognitive social capital (i.e., trust) is lower after the dams' construction. The effect of resettlement and compensation is more nuanced and qualified. This work suggests that hydropower projects have broad deleterious impacts on well‐being and health of human populations in hosting regions and that better directed efforts are required on the part of dam developers to reduce these negative outcomes.

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  4. Abstract

    We investigated how the taxonomic and functional structures of fish assemblages in the lower Amazon River floodplain responded to seasonal hydrological variations. Fishes were sampled in 440 aquatic habitats across a floodplain area of 17,673 km2during periods of high, receding, low and rising water. In addition, we recorded local environmental and landscape variables known to affect fish assemblages in floodplains. Redundancy analysis indicated that the taxonomic and functional structures of the fish assemblages were associated with water levels as well as local environmental, landscape and spatial variables. Our results showed that piscivores, planktivores and omnivores, as well as species with periodic and intermediate life history strategies, dominated the floodplain fish assemblages during periods of high‐water levels, whereas herbivores, invertivores and detritivores, as well as species of large body size with an equilibrium life history strategy, dominated the fish assemblages during periods of low‐water levels. Hydrology strongly influenced the structure of the fish assemblages in the Amazon floodplains. Our results indicate that the maintenance of seasonal hydrological dynamics in the basin is essential for the conservation of the regional fish diversity.

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  5. Following potential reforestation in the Amazon Basin, changes in the biophysical characteristics of the land surface may affect the fluxes of heat and moisture behavior. This research examines the impacts of potential tropical reforestation on surface energy and moisture budgets, including precipitation and temperature. The study is novel in that while most studies look at the opposite driver (deforestation), this one examines the impact of potential forest rehabilitation on atmospheric behavior using WRF.V3.9 (weather research and forecast model). We found that forest rehabilitation across the Amazon Basin can make the atmosphere cooler with more moisture and latent heat (LH), especially during May-November. For instance, the mean seasonal temperature decreased significantly by about 1.2 °C, indicating the cooling effects of reforestation. Also, the seasonal precipitation increased by 5 mm/day in reforested areas. By reforestation, the mean monthly LH also increased as much as 50 W m−2 in August in certain areas, while available moisture to the atmosphere increased by 27%, indicating possible causal mechanisms between increased LH and precipitation and emphasizing the mechanisms that were identified between the onset of the wet season and forest cover. Therefore, it is likely that forest regrowth across the basin leads to, if not reverses regional climate change, at least slowing down the rate of changes in the climate. 
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  6. Avaliamos as mudanças na dinâmica da pesca e nos aspectos sociais, econômicos, político-institucionais e ecológicos, em duas localidades do reservatório da Usina Hidroelétrica Santo Antônio: Distrito Jaci Paraná e Vila Nova do Teotônio, Rondônia, Brasil. A dinâmica pesqueira e o Índice do Desenvolvimento dos Pescadores do Médio Madeira (IDPM) foram obtidos e comparados entre os períodos: 2007/2009 e 2017/2019. Observamos: redução na captura e na contribuição das comunidades no mercado de Porto Velho; variações na composição das capturas, diminuição de algumas espécies; e diminuição na renda média mensal dos pescadores. O IDPM das localidades diminuiu no POSR e abaixo do ideal de desenvolvimento, influenciado pelo baixo desempenho dos indicadores ecológico e pesca. Ambas as localidades sofreram com as mudanças, os poucos pescadores que persistiram na atividade, demostram estratégias de adaptação ao novo cenário, com variações entre as localidades. 
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