REMOTE SENSING OF WATER BALANCE IN PANTANAL

Pantanal, located in the Upper Paraguay basin, is the world’s largest tropical wetland. The maintenance of this ecosystem depends on the water balance since precipitation is seasonal and high losses of water occur due to the high evapotranspiration. Water balance assessment using in situ data is still a challenge due to the large extension of the area and the complexity to be represented. In this study, the water balance in the Upper Paraguay basin was investigated based on hydrological variables derived from remote sensing data. Precipitation, evapotranspiration, and water storage change data were estimated with accuracy by the water balance, but the same was not possible for the discharge. However, high uncertainties in the estimates were verified, mainly during the rainy season. The remote sensing data allowed the identification of the seasonality of hydrological variables in the Pantanal system and in the different regions of the basin: Chaco, Pantanal and Planalto. Water deficit in the basin was observed from March/April to September as well as a positive water balance due to precipitation during the rest of the year. The spatial analysis of the basin showed that in the northern region, the precipitation, the evapotranspiration, and the water storage variation are higher than in the southern region. Results demonstrated that remote sensing data can help in the comprehension of hydrological systems operation, especially in large wetland regions

Estimativa de potencial energético de biogás proveniente do aterro sanitário Tijuquinhas (município de Biguaçu/SC)

Most solids waste in Brazil is disposed improperly, causing environmental, social and public health impacts. Methane, a product of anaerobic degradation of MSW, is considered to be an impactful greenhouse gas. This gas, burned or recycled properly in landfills for power generation, can bring financial returns for the company administrator, while minimizing environmental impacts. The objective of this study was to analyze the energy potential of landfill Biguaçu/SC using the methodologies proposed by the IPCC for theoretical estimation of biogas production. It was found that the landfill Biguaçu has high capacity power generation by exploiting methane, with a maximum potential of 5.26 MW in 2019, a year after the closure of the landfill.A maior parte dos resíduos sólidos urbanos (RSU) no Brasil é disposta de maneira inadequada, provocando impactos ambientais, sociais e de saúde pública. O metano, produto da degradação anaeróbia dos RSU, é considerado impactante por ser um gás de efeito estufa. Este gás, queimado ou aproveitado corretamente em aterros sanitários, para geração de energia, pode trazer retorno financeiro para a empresa administradora, além de minimizar impactos ambientais.  O objetivo deste trabalho foi analisar o potencial energético do aterro sanitário de Biguaçu/SC utilizando as metodologias propostas pelo IPCC para estimativa teórica de produção de biogás. Constatou-se que o aterro de Biguaçu possui alta capacidade de geração de energia através do aproveitamento de metano, com potencial máximo de 5,26 MW em 2019, um ano após o encerramento do aterro

Expressive fluxes over Amazon floodplain revealed by 2D hydrodynamic modelling

Water fluxes in the Amazon River floodplain affect hydrodynamic and ecological processes from local to global scales, but they remain poorly understood due to difficult accessibility and limited data. We characterized the hydrodynamics of eight floodplain units of the central Amazon River (40000 km2) using the 2D hydraulic model HEC-RAS. High resolution modelling (∼400 m) improved the representation of river and floodplain discharge, water surface elevation (77 cm accuracy) and flood extent (∼80% - high water period, ∼52% - low water period) compared to past modelling studies. Our results show that floodplain flows during floods are very intense with upstream inflow and downstream outflow of the floodplain units. These gross flows are much larger than the net flows, with values of up to 20% of the Amazon River discharge and residence time around 6 days during floods (several months during low water period). Water extent did not show strong interannual variability during floods as the volume stored in the floodplain did, possibly due to topographic constraints. Significant hysteresis in flood extent and volume, and active and storage zones on the floodplain highlight the complexity of floodplain hydrodynamics. Extreme floods strongly impacted the onset and duration of the flood by up to one month and, consequently on duration of high water renewal period with the river. Our characterization is important to assess the effects of extreme floods on riverine communities, understand nutrient and sediment variations in the floodplain, and characterize the export of water, sediment, and carbon flux to the ocean from the world's largest hydrological system

Increased floodplain inundation in the Amazon since 1980

Extensive floodplains throughout the Amazon basin support important ecosystem services and influence global water and carbon cycles. A recent change in the hydroclimatic regime of the region, with increased rainfall in the northern portions of the basin, has produced record-breaking high water levels on the Amazon River mainstem. Yet, the implications for the magnitude and duration of floodplain inundation across the basin remain unknown. Here we leverage state-of-the-art hydrological models, supported by in-situ and remote sensing observations, to show that the maximum annual inundation extent along the central Amazon increased by 26% since 1980. We further reveal increased flood duration and greater connectivity among open water areas in multiple Amazon floodplain regions. These changes in the hydrological regime of the world’s largest river system have major implications for ecology and biogeochemistry, and require rapid adaptation by vulnerable populations living along Amazonian rivers