scholarly journals The Rise of Climate-Driven Sediment Discharge in the Amazonian River Basin

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 208 ◽  
Author(s):  
Nazzareno Diodato ◽  
Naziano Filizola ◽  
Pasquale Borrelli ◽  
Panos Panagos ◽  
Gianni Bellocchi
Keyword(s):  
River Basin ◽  
Amazon Basin ◽  
Global Climate ◽  
Climate Extremes ◽  
Temporal Variations ◽  
Sediment Discharge ◽  
Storm Events ◽  
Discharge Data ◽  
Magdalena River ◽  
Sediment Export

The occurrence of hydrological extremes in the Amazon region and the associated sediment loss during rainfall events are key features in the global climate system. Climate extremes alter the sediment and carbon balance but the ecological consequences of such changes are poorly understood in this region. With the aim of examining the interactions between precipitation and landscape-scale controls of sediment export from the Amazon basin, we developed a parsimonious hydro-climatological model on a multi-year series (1997–2014) of sediment discharge data taken at the outlet of Óbidos (Brazil) watershed (the narrowest and swiftest part of the Amazon River). The calibrated model (correlation coefficient equal to 0.84) captured the sediment load variability of an independent dataset from a different watershed (the Magdalena River basin), and performed better than three alternative approaches. Our model captured the interdecadal variability and the long-term patterns of sediment export. In our reconstruction of yearly sediment discharge over 1859–2014, we observed that landscape erosion changes are mostly induced by single storm events, and result from coupled effects of droughts and storms over long time scales. By quantifying temporal variations in the sediment produced by weathering, this analysis enables a new understanding of the linkage between climate forcing and river response, which drives sediment dynamics in the Amazon basin.

Temporal variations of river basin waters from Topex/Poseidon satellite altimetry. Application to the Amazon basin

2001 ◽  
Vol 333 (10) ◽  
pp. 633-643 ◽  
Author(s):  
Ilce de Oliveira Campos ◽  
Franck Mercier ◽  
Caroline Maheu ◽  
Gérard Cochonneau ◽  
Pascal Kosuth ◽  
...  
Keyword(s):  
River Basin ◽  
Satellite Altimetry ◽  
Amazon Basin ◽  
Temporal Variations

scholarly journals Assessment of Temporal Variations of Orthometric/Normal Heights Induced by Hydrological Mass Variations over Large River Basins Using GRACE Mission Data

2020 ◽  
Vol 12 (18) ◽  
pp. 3070
Author(s):  
Walyeldeen Godah ◽  
Malgorzata Szelachowska ◽  
Jan Krynski ◽  
Jagat Dwipendra Ray
Keyword(s):  
River Basin ◽  
Amazon Basin ◽  
Principal Component ◽  
River Basins ◽  
Temporal Variations ◽  
Large River ◽  
Satellite Mission ◽  
Equivalent Water Thickness ◽  
Normal Heights ◽  
Large River Basins

Almost half of the Earth’s land is covered by large river basins. Temporal variations of hydrological masses induce time-varying gravitational potential and temporal mass loading that deforms the Earth’s surface. These phenomena cause temporal variations of geoid/quasigeoid and ellipsoidal heights that result in temporal variations of orthometric/normal heights ΔH/ΔH*. The aim of this research is to assess ΔH/ΔH* induced by hydrological masses over large river basins using the Gravity Recovery and Climate Experiment (GRACE) satellite mission data. The results obtained reveal that for the river basin of a strong hydrological signal, ΔH/ΔH* reach 8 cm. These ΔH/ΔH* would be needed to reliably determine accurate orthometric/normal heights. The ΔH/ΔH* do not exceed ±1 cm in the case of the river basin of the weak hydrological signal. The relation between hydrological mass changes and ΔH/ΔH* was investigated. Correlations between ΔH/ΔH* and temporal variations of equivalent water thickness were observed in 87% of river basins subareas out of which 45% exhibit strong correlations. The ΔH/ΔH* determined over two river basins that characterize with the strongest and weakest temporal variations were analysed using the Principal Component Analysis method. The results obtained reveal that ΔH/ΔH* in subareas of the same river basin can significantly differ (e.g., ±2 cm in the Amazon basin) from each other, and are strongly associated with different spatio-temporal patterns of the entire river basin.

scholarly journals The influence of rain in limnological characteristics of Viruá wetlands, Brazilian Amazon

2014 ◽  
Vol 26 (3) ◽  
pp. 254-267 ◽  
Author(s):  
Julio Daniel do Vale ◽  
Jansen Zuanon ◽  
William Ernest Magnusson
Keyword(s):  
Rainy Season ◽  
Amazon Basin ◽  
Global Climate ◽  
Temporal Variations ◽  
Large River ◽  
Water Transparency ◽  
Ecological Processes ◽  
Mean Values ◽  
Significant Difference ◽  
Local Rainfall

AIM: Floodplains occupy a vast area of the Amazon basin but little is known of how their physical and limnological characteristics respond to local and regional ecological processes. In the Negro River basin and its main tributary, the Branco River, there are large areas that are seasonally flooded by water from local rainfall and that are not directly connected to major rivers. One such area is the floodplain of Viruá National Park, in Roraima state, northern Brazil. METHODS: The physical and chemical limnological characteristics of 19 plots in this area were monitored over three years (2008‑2010), with samples collected each year at the beginning and end of the rainy season (May to August). RESULTS: The water bodies studied had low mean values for electrical conductivity (22.0 ± 14.0 µS*cm-1) and pH (4.8 ± 0.7), relatively high temperatures (26.6 ± 2.7 °C), and moderate values for dissolved oxygen saturation (43.0 ± 21.5%) and water transparency (87.9 ± 38.7 cm). There was no significant difference in the limnological characteristics of the aquatic plots between the beginning and end of the rainy seasons in 2008 and 2010, but there were significant differences in 2009 due to an atypical rainfall pattern with two short dry spells during the rainy season. Multivariate analysis showed that the highest temporal variations in the limnological characteristics of the aquatic plots resulted from changes in water transparency, and these changes were related to soil type, elevation of the plot, and the particular micro-basins to which they were connected. CONCLUSIONS: This dynamic is different from that of most floodplains in the Amazon region, where the limnological pattern is well-defined seasonally and strongly dependent on the direct connectivity to large river systems. Floodplains not connected to large rivers should receive special attention in relation to the expected impacts of global climate change because of their high dependence on local rainfall.

scholarly journals Spatio-Temporal Variations in COVID-19 in Relation to the Global Climate Distribution and Fluctuations

2021 ◽  
pp. 100417
Author(s):  
Olaniran Jonathan Matthew ◽  
Adebayo Oluwole Eludoyin ◽  
Kehinde Sunday Oluwadiya
Keyword(s):  
Global Climate ◽  
Temporal Variations ◽  
Spatio Temporal

Evidence of river flow regulation loss over time in the Magdalena river basin 

2021 ◽  
Author(s):  
Diver E. Marín ◽  
Juan F. Salazar ◽  
José A. Posada-Marín
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
River Basin ◽  
River Flow ◽  
Southern Oscillation ◽  
Scaling Theory ◽  
Scaling Properties ◽  
Low Flows ◽  
High Flows ◽  
Magdalena River

<p>Some of the main problems in hydrological sciences are related to how and why river flows change as a result of environmental change, and what are the corresponding implications for society. This has been described as the Panta Rhei context, which refers to the challenge of understanding and quantifying hydrological dynamics in a changing environment, i.e. under the influence of non-stationary effects. The river flow regime in a basin is the result of a complex aggregation process that has been studied by the scaling theory, which allows river basins to be classified as regulated or unregulated and to identify a critical threshold between these states. Regulation is defined here as the basin’s capacity to either dampen high flows or to enhance low flows. This capacity depends on how basins store and release water through time, which in turn depends on many processes that are highly dynamic and sensitive to environmental change. Here we focus on the Magdalena river basin in northwestern South America, which is the main basin for water and energy security in Colombia, and at the same time, it has been identified as one of the most vulnerable regions to be affected by climate change. Building upon some of our previous studies, here we use data analysis to study the evolution of regulation in the Magdalena basin for 1992-2015 based on the scaling theory for extreme flows. In contrast to most previous studies, here we focus on the scaling properties of events rather than on long term averages. We discuss possible relations between changes in the scaling properties and environmental factors such as climate variability, climate change, and land use/land cover change, as well as the potential implications for water security in the country. Our results show that, during the last few decades, the Magdalena river basin has maintained its capacity to regulate low flows (i.e. amplification) whereas it has been losing its capacity to regulate high flows (i.e. dampening), which could be associated with the occurrence of the extremes phases of  El Niño Southern Oscillation (ENSO) and anthropogenic effects, mainly deforestation. These results provide foundations for using the scaling laws as empirical tools for understanding temporal changes of hydrological regulation and simultaneously generate useful scientific evidence that allows stakeholders to take decisions related to water management in the Magdalena river basin in the context of environmental change.</p>

scholarly journals Breeding sites of Culicoides pachymerus Lutz in the Magdalena River basin, Colombia

2010 ◽  
Vol 105 (2) ◽  
pp. 216-219 ◽  
Author(s):  
María Cristina Carrasquilla ◽  
Felipe Guhl ◽  
Yaneth Zipa ◽  
Cristina Ferro ◽  
Raúl Hernando Pardo ◽  
...  
Keyword(s):  
River Basin ◽  
Breeding Sites ◽  
Magdalena River
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