Details

Autor(en) / Beteiligte

• Roland, Fábio
• Vidal, Luciana O.
• Pacheco, Felipe S.
• Barros, Nathan O.
• Assireu, Arcilan
• Ometto, Jean P. H. B.
• Cimbleris, André C. P.
• Cole, Jonathan J.

Titel

Variability of carbon dioxide flux from tropical (Cerrado) hydroelectric reservoirs

Ist Teil von

• Aquatic sciences, 2010-06, Vol.72 (3), p.283-293

Ort / Verlag

Basel: SP Birkhäuser Verlag Basel

Erscheinungsjahr

2010

Link zum Volltext

Quelle

SpringerLink (Online service)

Beschreibungen/Notizen

• Hydroelectric reservoirs generate energy without significant combustion of fossil fuels. However, these systems can, potentially, emit greenhouse gases (GHG’s) at a rate which may be significant at the global scale, and, possible, co-equal, per kilowatt-hour, to that from conventional coal or oil-fired systems. Although much of the new construction of hydroelectric reservoirs is in the tropics, most of the data on GHG emissions comes from temperate regions. Further, much of the existing data on reservoir gas emissions comes from single sites, usually near the terminal dams. Large tropical reservoirs often involve the impoundments of river systems with complex morphology which in turn can cause spatial heterogeneity in gas flux. We evaluated spatial and seasonal variability in CO 2 concentrations and gas flux for five large (50–1,400 km 2 ) reservoirs in the Cerrado region of Brazil. Most of data set (87% of all measurements) showed CO 2 supersaturation and net efflux to the atmosphere. There was as much or more variation in p CO 2 over space and among seasons. The large studied reservoirs showed different zones in terms of CO 2 emission because those fluxes are dependent on flooded biomass, watershed input of organic matter and dam operation regime. Here we demonstrate that the reservoirs in the Brazilian Cerrado have low rates of CO 2 emissions compared to existing global comparisons. Our results suggest that ignoring the spatial variability can lead to more than 25% error in total system gas flux.