Bohdan Matvienko

Bio: Bohdan Matvienko is an academic researcher from University of São Paulo. The author has contributed to research in topics: Greenhouse gas & Hydroelectricity. The author has an hindex of 8, co-authored 24 publications receiving 781 citations.

Carbon dioxide and methane emissions and the carbon budget of a 10-year old tropical reservoir (Petit Saut, French Guiana)

Abstract: emissions, 0.07 ± 0.01) the first 3 years after impounding (1994–1996) and then decreased to 0.12 ± 0.01 Mt yr 1 C( CO2, 0.10 ± 0.01; CH4, 0.016 ± 0.006) since 2000. On average over the 10 years, 61% of the CO2 emissions occurred by diffusion from the reservoir surface, 31% from the estuary, 7% by degassing at the outlet of the dam, and a negligible fraction by bubbling. CH4 diffusion and bubbling from the reservoir surface were predominant (40% and 44%, respectively) only the first year after impounding. Since 1995, degassing at an aerating weir downstream of the turbines has become the major pathway for CH4 emissions, reaching 70% of the total CH4 flux. In 2003, river carbon inputs were balanced by carbon outputs to the ocean and were about 3 times lower than the atmospheric flux, which suggests that 10 years after impounding, the flooded terrestrial carbon is still the predominant contributor to the gaseous emissions. In 10 years, about 22% of the 10 Mt C flooded was lost to the atmosphere. Our results confirm the significance of greenhouse gas emissions from tropical reservoir but stress the importance of: (1) considering all the gas pathways upstream and downstream of the dams and (2) taking into account the reservoir age when upscaling emissions rates at the global scale.

Greenhouse Gas Emissions from Hydroelectric Reservoirs in Tropical Regions

Abstract: This paper discusses emissions by power-dams in the tropics. Greenhouse gas emissions from tropical power-dams are produced underwater through biomass decomposition by bacteria. The gases produced in these dams are mainly nitrogen, carbon dioxide and methane. A methodology was established for measuring greenhouse gases emitted by various power-dams in Brazil. Experimental measurements of gas emissions by dams were made to determine accurately their emissions of methane (CH4) and carbon dioxide (CO2) gases through bubbles formed on the lake bottom by decomposing organic matter, as well as rising up the lake gradient by molecular diffusion.The main source of gas in power-dams reservoirs is the bacterial decomposition (aerobic and anaerobic) of autochthonous and allochthonous organic matter that basically produces CO2 and CH4. The types and modes of gas production and release in the tropics are reviewed.

Scientific Errors in the Fearnside Comments on Greenhouse Gas Emissions (GHG) from Hydroelectric Dams and Response to His Political Claiming

Abstract: LUIZ PINGUELLI ROSA1, MARCO AURELIO DOS SANTOS2, BOHDAN MATVIENKO3, ELIZABETH SIKAR4 and EDNALDO OLIVEIRA DOS SANTOS5 1Tenured Professor, Energy Planning Program, Graduate Engineering Programs Coordination Unit, Rio de Janeiro Federal University (PPE/COPPE/UFRJ) E-mail: lpr@adc.coppe.ufrj.br 2Contributing Professor, Energy Planning Program, Graduate Engineering Programs Coordination Unit, Rio de Janeiro Federal University (PPE/COPPE/UFRJ) E-mail: aurelio@ppe.ufrj.br 3Assistant Professor, Water Resources and Applied Ecology Center, Sao Paulo University (CRHEA/USP/SC) E-mail: bohdan@linkway.com.br 4Construmaq Sao Carlos E-mail: elizabeth@linkway.com.br 5Doctoral Student, Atmospheric Sciences, Graduate Engineering Programs Coordination Unit, Rio de Janeiro Federal University (COPPE/UFRJ) E-mail: eos@ivig.coppe.ufrj.br

Biogenic gas production from major Amazon reservoirs, Brazil

Abstract: Methane (CH 4 ) and carbon dioxide (CO 2 ) emissions from Brazilian reservoirs were assessed. Point measurements were made during 1998 and 1999 (using inverted funnels for bubbles and air and water concentration gradients for diffusion) in the 559 km 2 Samuel reservoir, which was initially flooded in 1988, and the 2430 km 2 Tucurui reservoir, which was flooded in 1984, and the data were evaluated with respect to historical measurements in other Brazilian reservoirs. Bubble emissions of CH 4 were higher in Samuel (ranging from 2 to 70 mgCH 4 m -2 day -1 ) than in Tucurui (ranging from 0.5 to 30 mgCH 4 m -2 day -1 ), with the highest values occurring the shallowest regions in each reservoir. CH 4 from diffusion for the Tucurui reservoir ranged from 5 to 30 mgCH 4 m -2 day - 1 , which is lower than that for the Samuel reservoir, which ranged from 10 to 80 mgCH 4 m -2 day -1 The smaller emissions in Tucurui compared with Samuel are attributed to a larger depletion in the source organic material that was present when the reservoir was filled. The CO 2 concentration was similar for each reservoir, and ranged from 1000 to 10000 mgCO 2 m -2 day -1 .

Gas release from a reservoir in the filling stage

Abstract: (2000). Gas release from a reservoir in the filling stage. SIL Proceedings, 1922-2010: Vol. 27, No. 3, pp. 1415-1419.

Fragmentation and flow regulation of the world's large river systems

Abstract: A global overview of dam-based impacts on large river systems shows that over half (172 out of 292) are affected by dams, including the eight most biogeographically diverse. Dam-impacted catchments experience higher irrigation pressure and about 25 times more economic activity per unit of water than do unaffected catchments. In view of projected changes in climate and water resource use, these findings can be used to identify ecological risks associated with further impacts on large river systems.

Lakes and reservoirs as regulators of carbon cycling and climate

Abstract: We explore the role of lakes in carbon cycling and global climate, examine the mechanisms influencing carbon pools and transformations in lakes, and discuss how the metabolism of carbon in the inland waters is likely to change in response to climate. Furthermore, we project changes as global climate change in the abundance and spatial distribution of lakes in the biosphere, and we revise the estimate for the global extent of carbon transformation in inland waters. This synthesis demonstrates that the global annual emissions of carbon dioxide from inland waters to the atmosphere are similar in magnitude to the carbon dioxide uptake by the oceans and that the global burial of organic carbon in inland water sediments exceeds organic carbon sequestration on the ocean floor. The role of inland waters in global carbon cycling and climate forcing may be changed by human activities, including construction of impoundments, which accumulate large amounts of carbon in sediments and emit large amounts of methane to the atmosphere. Methane emissions are also expected from lakes on melting permafrost. The synthesis presented here indicates that (1) inland waters constitute a significant component of the global carbon cycle, (2) their contribution to this cycle has significantly changed as a result of human activities, and (3) they will continue to change in response to future climate change causing decreased as well as increased abundance of lakes as well as increases in the number of aquatic impoundments.

Global carbon dioxide emissions from inland waters

Abstract: Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8(-0.25)(+0.25) petagrams of carbon (Pg C) per year from streams and rivers and 0.32(-0.26)(+0.52) Pg C yr(-1) from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1 Pg C yr(-1) is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally.

Assessment of sustainability indicators for renewable energy technologies

Abstract: The non-combustion based renewable electricity generation technologies were assessed against a range of sustainability indicators and using data obtained from the literature. The indicators used to assess each technology were price of generated electricity, greenhouse gas emissions during full life cycle of the technology, availability of renewable sources, efficiency of energy conversion, land requirements, water consumption and social impacts. The cost of electricity, greenhouse gas emissions and the efficiency of electricity generation were found to have a very wide range for each technology, mainly due to variations in technological options as well as geographical dependence of each renewable energy source. The social impacts were assessed qualitatively based on the major individual impacts discussed in literature. Renewable energy technologies were then ranked against each indicator assuming that indicators have equal importance for sustainable development. It was found that wind power is the most sustainable, followed by hydropower, photovoltaic and then geothermal. Wind power was identified with the lowest relative greenhouse gas emissions, the least water consumption demands and with the most favourable social impacts comparing to other technologies, but requires larger land and has high relative capital costs.